PT - Conference TI - The New Horizons Mission: Pluto and the Kuiper Belt Up-Close AU - Singer, K. N. AU - Stern, A. AU - Moore, J. M. AU - Spencer, J. R. AU - McKinnon, W. B. AU - White, O. L. AU - Schenk, P. AU - Porter, S. AU - Verbiscer, A. AU - Parker, A. H. AU - Buie, M. W. AU - Showalter, M. AU - Umurhan, O. M. AU - Young, L. A. AU - Binzel, R. P. AU - Grundy, W. M. AU - Protopapa, S. AU - Weaver, H. A., Jr. AU - Olkin, C. AU - Ennico Smith, K. AU - Parker, J. W. TA - AGU Fall Meeting Abstracts SO - American Geophysical Union, Fall Meeting 2019, abstract #P54B-09 VI - 2019 DP - 2019 Dec 01 PG - P54B-09 4099- https://ui.adsabs.harvard.edu/abs/2019AGUFM.P54B..09S AB - In July of 2015 the New Horizons spacecraft flew through the Pluto system, initiating humanity's close-up exploration of Kuiper belt objects (Stern et al., 2015, Science). Pluto turned out to be a world of remarkable geologic diversity whose terrains display a range of ages and varied compositions, suggesting geologic activity of various forms (both endogenic and exogenic) has persisted for much of Pluto's history (e.g., Moore et al., 2016, Science). This was a surprise given Pluto's size and lack of recent tidal energy inputs. Many discoveries were also made about Pluto's complex atmosphere, including the existence of many haze layers. Pluto's large moon Charon appears to have had an early large cyrovolcanic resurfacing episode along with large-scale extensional tectonism. On January 1 of 2019 New Horizons encountered its second target, a cold classical Kuiper belt object approximately 35 km across at 43 AU (Stern et al., 2019, Science). This is the farthest and most primordial planetary body ever explored in detail. Its flattened, snowperson-like shape and unique surface features are helping us learn about the earliest times in the solar system and how planetary bodies formed (Spencer et al., 2019, Science; McKinnon et al., 2019, Science). No satellites or rings were found. MU69's surface has the signature of H2O and CH3OH (methanol) and a very red color, indicative of other organics. This presentation will highlight some of the unique aspects of the Pluto-system, and give an update on the ongoing work to further unveil its secrets. We will also present an overview of what New Horizons is learning about the Kuiper belt as a whole (from Pluto to MU69 to distant KBO observations) and what new information this gives us about planetesimal and planet formation.

PT - Conference TI - Triton's Surface Composition: Reevaluation of Voyager colors from the perspective of New Horizons at Pluto AU - Schenk, P. AU - Grundy, W. M. AU - Hansen, C. J. AU - Howett, C. AU - Prockter, L. M. TA - AGU Fall Meeting Abstracts SO - American Geophysical Union, Fall Meeting 2019, abstract #P53D-3492 VI - 2019 DP - 2019 Dec 01 PG - P53D-3492 4099- https://ui.adsabs.harvard.edu/abs/2019AGUFM.P53D3492S AB - New Horizons mapping of Pluto the best known Kuiper Belt Object (KBO), revealed the presence of surface ices (including CO, CH4, N2, and H2O) and their geologic distribution. Triton, the largest moon of Neptune, is very similar in size and bulk density to Pluto and was likely a KBO before capture. Both bodies orbit at comparable distances from the Sun (though Pluto goes further out) and have similar rotation periods. Both have complex obliquity cycles and both may have been or are ocean worlds. Triton is also a priority target for future exploration. Voyager (VGR) color mapping lacked the infrared capabilities of New Horizons (NH), rendering compositional mapping very difficult, but also revealed complex geologic and atmospheric color patterns on the surface of Triton. These include color changes at unit boundaries and equatorial bright and dark regional patterns uncorrelated to geology with very strong UV signatures. Small dark spots that appear wind-blown also have distinct spectral signatures. We have remapped the color data for Triton using updated cartography. VGR did extend into the UV which allows comparisons to Cassini icy moons color mapping. Color filter bandpasses for VGR & NH overlap in the 0.4 and 0.6 micron bands, which allows for a comparison of the brightness and spectral slopes of color units on the two bodies. The presence of CO2 on Triton will produce a distinct spectral signature compared to Pluto. Principle component analysis will be updated using all 6 filters to identify distinctive surface components. Disk integrated color rotational coverage from Earth-based spectra may also permit correlation of specific color units with identified longitudinal concentrations of ice phases.

PT - Conference TI - Pluto Refractory Material AU - Dalle Ore, C. AU - Cruikshank, D. P. AU - Grundy, W. M. AU - Cook, J. C. AU - Ennico Smith, K. AU - Olkin, C. AU - Stern, A. AU - Weaver, H. A., Jr. AU - Young, L. A. TA - AGU Fall Meeting Abstracts SO - American Geophysical Union, Fall Meeting 2019, abstract #P43C-3486 VI - 2019 DP - 2019 Dec 01 PG - P43C-3486 4099- https://ui.adsabs.harvard.edu/abs/2019AGUFM.P43C3486D AB - One of Pluto's unexpected discoveries has been the variety of terrains that characterize its surface. This bounty of data has given us the opportunity to investigate the composition of the different regions to compare and contrast the non-icy refractory component(s) of Pluto's surface. The colored materials that are the target of our investigation are thought to originate either from haze deposition, or from ejection from a liquid water sub-crustal reservoir, or from surface irradiation of the hydrocarbon ices. Considering the dynamic nature of Pluto's surface, continually refreshed and/or renewed, the possibility of a primordial component is remote. We compare the refractory material of different regions of Pluto's surface and attempt at identifying their origin.

PT - Conference TI - On the solar nebula origin of (486958) 2014 MU69, a primordial contact binary in the Kuiper belt AU - McKinnon, W. B. AU - Grundy, W. M. AU - Hamilton, D. AU - Umurhan, O. M. AU - Keane, J. T. AU - Spencer, J. R. AU - Olkin, C. AU - Weaver, H. A., Jr. AU - Stern, S. A. TA - AGU Fall Meeting Abstracts SO - American Geophysical Union, Fall Meeting 2019, abstract #P42C-05 VI - 2019 DP - 2019 Dec 01 PG - P42C-05 4099- https://ui.adsabs.harvard.edu/abs/2019AGUFM.P42C..05M AB - MU69 is a contact binary, and all the data returned from New Horizons are consistent with it being a planetesimal. It is not a product of heliocentric, high-speed collisional evolution. There is no evidence of it having suffered a catastrophic or even a subcatastrophic impact during its lifetime. Nor is there evidence of hierarchical accretion of independent, heliocentric planetesimals, as slow as those collisions may have been in the beginning. Rather, there is strong evidence that its two lobes ("Ultima" and "Thule") came together at an extremely low velocity, on the order of no more than a couple of m/s and possibly much more slowly. Binary formation is a theoretically predicted common outcome in protoplanetary disks when swarms of locally concentrated solids ("pebble clouds") collapse under their own gravity, and plausibly explains the high fraction of binaries among cold classical Kuiper belt objects (KBOs). Cold classical KBO binaries exhibit a range of binary orbital separations, down to the observable limit, so there is no physical reason that tight or even contact binaries could not form in a collapsing pebble cloud. The prominence of bilobate shapes among the short-period comets, which are derived from the scattered disk component of the Kuiper belt, suggests (but does not require) that there is a process that collapses or hardens Kuiper belt binaries. The alignment of the principal axes of the Ultima and Thule lobes is also consistent with tidal coupling between two co-orbiting bodies, prior to a final merger. Our examination of various mechanisms to drive binary mergers in the cold classical Kuiper belt (Kozai-Lidov, BYORP, tides, collisions, gas drag) highlights the potential importance of gas drag while the protosolar nebula is still present. We find the process to be surprisingly effective, because in a gas nebula with a radial pressure gradient the velocity of the gas deviates from the heliocentric Keplerian velocity of the binary. The headwind that the binary feels couples to the motion of the binary pair about its own center of mass. The resulting viscous, Stokes-regime gas drag can collapse MU69-scale co-orbiting binaries—as well as smaller, cometary-scale binaries—within the few-Myr lifetime of the protosolar gas nebula.

PT - Conference TI - Surface compositions and colors of Pluto, its system of moons, and 2014 MU69 AU - Protopapa, S. AU - Grundy, W. M. AU - Cruikshank, D. P. AU - Reuter, D. AU - Olkin, C. AU - Ennico Smith, K. AU - Parker, J. W. AU - Singer, K. N. AU - Spencer, J. R. AU - Stern, S. A. AU - Verbiscer, A. AU - Weaver, H. A., Jr. TA - AGU Fall Meeting Abstracts SO - American Geophysical Union, Fall Meeting 2019, abstract #P42C-04 VI - 2019 DP - 2019 Dec 01 PG - P42C-04 4099- https://ui.adsabs.harvard.edu/abs/2019AGUFM.P42C..04P AB - The trans-neptunian population is extremely diverse, with bodies ranging from geologically-active, atmosphere-bearing, volatile-dominated dwarf planets to small primitive planetesimals lacking abundant surface volatile ices (e.g., methane, nitrogen, carbon monoxide)---what we think of as the building blocks of planets. Our understanding of the Kuiper Belt has been limited by the challenges of acquiring high-quality spectroscopy for midsize and small trans-neptunian objects and composition maps of large dwarf planets. NASA's New Horizons mission represents a breakthrough in our understanding of the trans-neptunian population providing a detailed portrait of objects with very different size scales: the 2400-km-diameter dwarf planet Pluto, the midsize ~1200 -km-diameter body Charon, and the much smaller Pluto's satellites (e.g., Nix and Hydra) and (486958) 2014 MU69 (hereafter MU69), the latter with an 18 km equivalent spherical diameter. This is the result of two successful flybys: that of Pluto and its moons on July 14th, 2015 (Stern, S. A., Bagenal, F., Ennico, K., et al. 2015, Science, 350, aad1815), and that of MU69 on January 1st, 2019 (Stern, S. A., Weaver, H. A., Spencer, J. R., et al. 2019, Science, 364, aaw9771). We will present an overview of the color and composition of these very diverse bodies in terms of size, evolutionary stage, and dynamical class in the broad context of the physical and chemical properties of other trans-neptunian objects. Comparing and contrasting these objects will shed light on the mechanisms at play during the epoch of planet formation in the Third Zone of the Solar System.

PT - Conference TI - The Geology and Formation of the Kuiper Belt Object 2014 MU69 AU - White, O. L. AU - Moore, J. M. AU - McKinnon, W. B. AU - Stern, S. A. AU - Weaver, H. A., Jr. AU - Olkin, C. AU - Spencer, J. R. AU - Parker, J. W. AU - Verbiscer, A. AU - Grundy, W. M. TA - AGU Fall Meeting Abstracts SO - American Geophysical Union, Fall Meeting 2019, abstract #P42C-01 VI - 2019 DP - 2019 Dec 01 PG - P42C-01 4099- https://ui.adsabs.harvard.edu/abs/2019AGUFM.P42C..01W AB - The New Horizons flyby of the small Kuiper Belt Object 2014 MU69 provided the first look at the geology of a member of the Cold Classical Kuiper Belt, the most primitive known population of objects in the solar system. MU69 is a contact binary, composed of two sharply distinct components (nicknamed "Ultima" and "Thule") that make contact at a bright, narrow, "neck". Both are flattened, with their smallest axes aligned, and their contact point is close to the longest axis of both bodies. This configuration strongly suggests that the two components formed independently, and orbited each other in a tidally locked configuration before coming gently together. The current rotation period of 15.92 hours is slow enough that, for reasonable densities, the two bodies must have lost significant angular momentum after contacting each other. On both components, the surface is generally smooth, though pits are seen near the terminator, and bright spots away from the terminator may also be bright-floored pits. If impact-generated, these features indicate a surface age dating to the era of planetary accretion. Ultima, the larger component, is highly flattened, with approximate dimensions 20.6 × 19.9 × 9.4 km. Thule is closer to spherical than Ultima, with approximate dimensions 15.4 × 13.8 × 9.8 km. In both cases, the shortest dimension is the least certain. Ultima appears to be divided into several sub-units, distinguished by surface texture and/or separated by linear scarps or bright linear albedo features. Dark features that appear to be low hills and ridges are unevenly distributed across the surface. The sub-units may provide evidence for assembly of Ultima from smaller bodies, though the continuity of some surface texture units across some of the bounding linear features argues for some of the unit boundaries being relatively young rather than primordial. Thule is markedly different in appearance. It is dominated by a large depression (nicknamed "Maryland") that is 7 km across and 0.5-1 km deep, and which is likely to be an impact feature. The rest of the surface is characterized by bright and dark albedo markings that often have strikingly sinuous boundaries, possibly due to sublimation erosion of thin, discrete surface layers. This work was supported by the NASA New Horizons project.

PT - Conference TI - Pluto's Surface Properties from the New Horizons Uplink Bistatic Radar Experiment AU - Linscott, I. AU - Asmar, S. AU - Bird, M. AU - DeBoy, C. AU - Sepan, R. AU - Stern, A. AU - Vincent, M. AU - Oudrhiri, K. AU - Paetzold, M. AU - Andert, T. AU - Hinson, D. P. AU - Tyler, G. L. AU - Weaver, H. A., Jr. AU - Young, L. A. AU - Grundy, W. M. AU - Olkin, C. AU - Ennico Smith, K. TA - AGU Fall Meeting Abstracts SO - American Geophysical Union, Fall Meeting 2019, abstract #P34A-01 VI - 2019 DP - 2019 Dec 01 PG - P34A-01 4099- https://ui.adsabs.harvard.edu/abs/2019AGUFM.P34A..01L AB - Exploration of planetary surface properties by scattering radio signals has been carried out via Solar System spacecraft for nearly six decades. During the New Horizons flyby of Pluto on July 14, 2015, an innovative approach reversed the radio path using a high-power uplink transmitted from the Deep Space Network. The uplink illuminated the surface of Pluto, and the scattered signals were recorded onboard the spacecraft by REX the Radioscience instrument, setting a record at 7.6 Bkm for bistatic radar. The high SNR advantage, needed to characterize such a distant object, was nearly three orders of magnitude greater than traditional downlink experiments could have provided. The bistatic experiment was performed using a radar transmission at 7.18 GHz, from the NASA's Deep Space Network 34-m diameter antenna (designated DSS-26) at Goldstone, California. The transmission was CW at 80 kilowatts in right-hand circular polarization (RCP) and was adjusted in frequency to compensate for predicted Doppler shifts to ensure it would fall within REX's 1.25 kHz bandpass. The received signal's SNR was 30x, (15 dB), and digitized by REX in both polarizations, and in-phase and quadrature, revealing a polarization ratio of ~1/2, and a surface reflectivity of ~0.3. The radar illumination at Pluto's specular point subtended an angle of incidence between 40 degrees and 60 degrees, a near-optimal geometry for modelling surface properties. Characterization of Pluto's surface in the vicinity of the specular point has incorporated Fresnel reflection, as well as electromagnetic scattering models for randomly oriented surface facets as well as subsurface propagation and multidimensional optimization over the distribution of surface slopes and roughness, to obtain both the composition and structure of Pluto's surface and subsurface. These results demonstrate the efficacy of bistatic scattering for planetary surface characterization and suggest that bistatic experiments, if incorporated in future missions to the solar system's planets, moons, dwarf planets and bodies, will substantially increase and enrich their science return.

PT - Conference TI - On the Stability & Origin of MU69's and Pluto's Ices AU - Lisse, C. M. AU - Young, L. A. AU - Cruikshank, D. P. AU - Sandford, S. A. AU - Stern, A. AU - Weaver, H. A., Jr. AU - Umurhan, O. M. AU - Pendleton, Y. J. AU - Keane, J. T. AU - Gladstone, R. AU - Parker, J. W. AU - Binzel, R. P. AU - Earle, A. M. AU - Horanyi, M. AU - Elmaarry, M. R. AU - Cheng, A. F. AU - McNutt, R. L., Jr. AU - Moore, J. AU - Grundy, W. M. AU - Schmitt, B. AU - Kavelaars, J. J. AU - Linscott, I. AU - Britt, D. T. AU - Spencer, J. R. AU - Olkin, C. AU - Elliott, H. A. TA - AGU Fall Meeting Abstracts SO - American Geophysical Union, Fall Meeting 2019, abstract #P33I-3540 VI - 2019 DP - 2019 Dec 01 PG - P33I-3540 4099- https://ui.adsabs.harvard.edu/abs/2019AGUFM.P33I3540L AB - In this paper we discuss in a model-independent way the nature of the stable, refractory ices that could be present in Kuiper Belt object (KBO) 2014 MU69 ("Ultima Thule") after its 4.6 Gyr residence in the Edgeworth-Kuiper belt (EKB) as a cold classical object, and the processes that could affect them, such as short-lived radioactive decay, x-ray/ultraviolet photon (XUV) and galactic cosmic ray (GCR) irradiation, and micrometeorite bombardment. We compare the upper bounds for the gas production rate (~10²⁴molecules/sec) measured by the New Horizons spacecraft flyby on 01 Jan 2019 to estimates for the outgassing flux rates from a suite of common cometary and KBO ices at the average ~40K sunlit surface temperature of UT, but do not find the upper limit very constraining except for the most volatile of species (eg CO, N₂, CH₄). More constraining is the stability versus sublimation into vacuum requirement over Myr to Gyr, and from this we find only 3 common ices that are truly refractory: HCN, CH₃OH, and H₂O (in order of increasing stability), while NH₃and H₂CO ices are marginally stable and may be removed by any positive temperature excursions in the EKB, as produced every 10⁸- 10⁹yrs by nearby supernovae (SN) and passing O/B stars. To date the New Horizons (NH) team has reported the presence of abundant CH₃OH and H₂O on MU69's surface (Stern+ 2019, Grundy+ 2019). NH₃has been searched for, but not found. We predict that future absorption feature detections, if any are ever derived from higher SNR spectra, will be due to an HCN or poly-H₂CO based species.

Consideration of the conditions present in the EKB region during the formation era of MU69 lead us to state that it is highly likely that it "formed in the dark", unable to see the nascent, variable, highly luminous YSO/TTauri Sun, in an optically thick proto-planetary disk (PPD) mid-plane. Also, that KBOs contain pure CH₃OH (and likely HCN) ice phases in addition to the H₂O ice and H₂O ice clathrates found in their short period (SP) comet descendants. Finally, when we apply our ice thermal stability analysis to bodies/populations related to MU69, we find that that Pluto must have gained its hypervolatiles from PPD sources in the first few Myr of the solar system's existence, that comet C/2016 R2 was placed onto an Oort Cloud orbit on a similar timescale, and that the O₂in comet 67P is not primordial.

PT - Conference TI - Impact craters on 2014 MU69: Implications for Kuiper belt object size-frequency distributions and planetesimal formation AU - Singer, K. N. AU - Spencer, J. R. AU - McKinnon, W. B. AU - Stern, A. AU - Greenstreet, S. AU - Gladman, B. AU - Robbins, S. J. AU - Runyon, K. AU - Schenk, P. AU - Kavelaars, J. J. AU - Lauer, T. AU - Parker, A. H. AU - Weaver, H. A., Jr. AU - Olkin, C. AU - Moore, J. AU - Parker, J. W. AU - Verbiscer, A. AU - Grundy, W. M. TA - AGU Fall Meeting Abstracts SO - American Geophysical Union, Fall Meeting 2019, abstract #P33I-3535 VI - 2019 DP - 2019 Dec 01 PG - P33I-3535 4099- https://ui.adsabs.harvard.edu/abs/2019AGUFM.P33I3535S AB - Impact craters in the Pluto system as observed by New Horizons in July of 2015 revealed a previously-unknown deficit of small Kuiper belt objects (KBOs) less than ~1-2 km in diameter (Singer et al., 2019, Science) . New Horizons was poised to test this observation 3.5 years later with its next KBO close flyby of the cold classical KBO (486958) 2014 MU69 (nicknamed Ultima Thule). The images returned by New Horizons in early 2019 show MU69 is only modestly cratered, and potential craters on the surface show a shallow size-frequency distribution (SFD) similar to that of craters on Pluto and Charon (Stern et al. 2019, Science; Singer et al., 2019, EPSC-DPS; Spencer et al. 2019, Science).

Some features on MU69 do have multiple morphologic indicators suggesting they are impact craters. There are regions on MU69 with few-to-no craters, even where the lighting is favorable for recognizing topographic features. The ~7-km-diameter depression (informally called Maryland) on the small lobe of MU69 is the largest easily observed feature that is likely to be an impact crater. There are also craters under 1 km in diameter, but no obvious craters between 1 and 7 km in diameter.

The possible impact craters < ~1 km in diameter were divided into subgroups based on morphology, likelihood of being a crater , lighting geometry, and also into one possible geologic unit. Measurements/ratings were provided by several team members. All subgroups produced shallow- sloped SFDs (differential power-law slope ≲ −2) similar to those seen on Pluto and Charon for the same size craters (when scaled for gravity and impact velocity). Whole-sale resurfacing through geologic processes is not expected for MU69. Thus many more craters and at least some heavily cratered terrains would be predicted if the impactor SFD slope were steeper (an average differential slope closer to −3; Greenstreet et al. 2019, ApJ). Both the apparent lack of craters overall, and the shallow SFD slopes, are consistent with a relatively benign collisional environment for MU69 (McKinnon et al., 2019, Science).

PT - Conference TI - A Statistical Test for the Population of Contact Binaries in the Kuiper Belt AU - Showalter, M. AU - Benecchi, S. AU - Buie, M. W. AU - Grundy, W. M. AU - Keane, J. T. AU - Lisse, C. M. AU - Olkin, C. AU - Porter, S. AU - Robbins, S. J. AU - Singer, K. N. AU - Verbiscer, A. AU - Weaver, H. A., Jr. AU - Zangari, A. M. AU - Hamilton, D. P. AU - Kaufmann, D. E. AU - Lauer, T. AU - Mehoke, D. S. AU - Mehoke, T. S. AU - Spencer, J. R. AU - Throop, H. AU - Parker, J. W. AU - Stern, S. A. TA - AGU Fall Meeting Abstracts SO - American Geophysical Union, Fall Meeting 2019, abstract #P33I-3532 VI - 2019 DP - 2019 Dec 01 PG - P33I-3532 4099- https://ui.adsabs.harvard.edu/abs/2019AGUFM.P33I3532S AB - New Horizons images of Kuiper Belt object (486958) 2014 MU69 dramatically revealed that it is a contact binary, comprising two flattened lobes attached by a very narrow neck. In spite of its highly elongated shape, MU69 has a rotational light curve with an amplitude that was too small to be measured from Earth or during the approach of the spacecraft in December 2018. This surprising result is, in part, a consequence of MU69's bilobate shape; in general, contact binaries have light curve amplitudes that are systematically lower than those of equivalent-area ellipsoids.

The prevalence of contact binaries among the cold classical KBOs (CCKBOs) has been a topic of investigation on several fronts. We find that an important constraint on the answer to this question can be inferred from the statistical distribution of light curve amplitudes among CCKBOs. We have modeled these distributions based on a variety of assumptions, including rough or irregular shapes, albedo variations, degree of flattening, the size of the neck, and the size ratio of the two lobes. We have also explored the dependence on the statistical distribution of KBO orientations, assuming that the rotation poles are either completely random or are preferentially oriented normal to the orbit plane. In all cases, the distribution of light curve amplitudes is predicted to be lower if contact binaries are prevalent among the CCKBOs.

At this time, the limited available data on CCKBO light curve amplitudes does not permit a definitive answer to the question of how many CCKBOs are contact binaries. However, the statistical test holds promise as more CCKBOs are observed. It would complement the shape determinations based on the direct modeling of KBOs with high-amplitude light curves, combined with further occultation studies of KBO shapes. Needed is a large and an unbiased sample of light curve amplitudes, one which does not focus on the high-amplitude light curves that are often of greatest interest.

PT - Conference TI - Update on High Resolution Searches for KBO Binaries using New Horizons LORRI AU - Weaver, H. A., Jr. AU - Porter, S. B. AU - Spencer, J. R. AU - Stern, S. A. AU - Verbiscer, A. AU - Benecchi, S. AU - Binzel, R. P. AU - Buie, M. W. AU - Buratti, B. J. AU - Cheng, A. F. AU - Cruikshank, D. P. AU - Grundy, W. M. AU - Kavelaars, J. J. AU - Lauer, T. AU - Lisse, C. M. AU - Moore, J. AU - Olkin, C. AU - Parker, A. H. AU - Parker, J. W. AU - Young, L. A. AU - Zangari, A. M. TA - AGU Fall Meeting Abstracts SO - American Geophysical Union, Fall Meeting 2019, abstract #P33I-3531 VI - 2019 DP - 2019 Dec 01 PG - P33I-3531 4099- https://ui.adsabs.harvard.edu/abs/2019AGUFM.P33I3531W AB - The New Horizons (NH) spacecraft has been traversing the Kuiper belt for the past four years, enabling observations of known Kuiper belt objects (KBOs) at unique geometries, including at large phase angles not possible from the inner solar system and at ranges that provide higher spatial resolution than available from Earth, or Earth-orbiting, facilities. New Horizons carries a large aperture (20.8 cm) visible light imaging system, the LOng Range Reconnaissance Imager (LORRI), whose resolution (IFOV=1,4 arcsec for 1x1 and 4x4 modes, respectively) permits searches for binaries at finer spatial scales than available from the Hubble Space Telescope (HST). We have already observed 13 KBOs (1 Plutino, 1 Hot Classical, 1 Scattered Disk, and 10 Cold Classicals) that passed within 1 AU of the NH spacecraft, and two more KBOs are scheduled for observations in early September 2019. We are actively searching for additional candidates using ground-based telescopes. Five of the observed KBOs passed within 0.2 AU of the NH spacecraft, including two with ranges of ~0.11 AU (82 km/pix for 1x1 mode). LORRI's photometric sensitivity for these satellite searches (V~16.3 in 1x1 mode after co-adding ~125 0.5s exposures; V~21 in 4x4 mode after co-adding ~50 30s exposures, and even deeper after implementing 64s exposures in fall 2019) is comparable to, or exceeds, that available from HST. Five of the six highest resolution (1x1 mode) NH KBO satellite searches were performed during the latter half of 2018, and some of those data are scheduled for downlink in Oct-Nov 2019. Here we report on the binary search limits achieved for the 1x1 data that were downlinked by the end of Nov 2019.

PT - Conference TI - Probing the regoliths of the classical Uranian satellites using near-infrared telescope observations: CO2 ice deposits mantled by a veneer of tiny H2O ice grains? AU - Cartwright, R. J. AU - Emery, J. P. AU - Pinilla-Alonso, N. AU - Grundy, W. M. AU - Cruikshank, D. P. TA - AGU Fall Meeting Abstracts SO - American Geophysical Union, Fall Meeting 2019, abstract #P32A-08 VI - 2019 DP - 2019 Dec 01 PG - P32A-08 4099- https://ui.adsabs.harvard.edu/abs/2019AGUFM.P32A..08C AB - In the late 1970s and early 1980s, near-infrared (NIR) ground-based observations (~1 - 2.5 µm) determined that the surfaces of the large and tidally-locked "classical" moons of Uranus are composed of H₂O ice, mixed with a dark, C-rich constituent. In the late 1990s and early 2000s, CO₂ ice was detected in NIR spectra of these moons, with spectral properties remarkably similar to the second and third order combination and overtone bands of CO₂ ice (between 1.9 to 2.1 µm and 1.57 to 1.61 µm, respectively). The presence of these relatively weak CO₂ bands indicates that the detected CO₂ ice is retained in thick deposits (~1 - 100 mm) on the surfaces of these moons. However, over longer NIR wavelengths (~3 - 5 µm), the spectral signature of CO₂ ice is mostly absent from these moons. Photon penetration depths into H₂O-rich particulate surfaces are a steep function of wavelength, with NIR photons between 1 and 2.5 µm penetrating deeper (~0.15 - 10 mm depths) than NIR photons between 3 and 5 µm (~0.001 - 0.05 mm depths). Thus, we hypothesize that the regoliths of the classical Uranian satellites are compositionally stratified, with thick deposits of CO₂ ice retained beneath a veneer of tiny H₂O ice grains.

To test this hypothesis, we have collected data using the Infrared Array Camera (IRAC) onboard the Spitzer Space Telescope (spanning ~3 to 5 µm). We compared these new IRAC data to an IRAC dataset collected previously, as well as longer NIR spectra, spanning 3 to 4 µm. Analysis of these longer NIR datasets indicates that the Uranian moons are relatively bright over the 3 to 5 µm range, with enhanced 3.6-µm H₂O ice peaks. Best fit spectral models of the IRAC datasets are primarily composed of tiny H₂O ice grains (≤ 2 µm diameters), with no trace of CO₂ ice. Thus, our analyses support compositional stratification of these moons' regoliths. We explore some of the processes that could generate layered media on the Uranian moons and discuss why the surfaces of icy Jovian and Saturnian moons lack similar veneers of tiny H₂O ice grains. Additionally, we discuss how next generation telescopes and future spacecraft missions would revolutionize our understanding of the classical Uranian moons and ice giant planetary systems.

PT - Conference TI - Titan's Bistable Climate and the Origin of its Atmospheric Methane AU - Steckloff, J. AU - Soto, A. AU - Soderblom, J. M. AU - Farnsworth, K. AU - Chevrier, V. F. AU - Hanley, J. AU - Grundy, W. M. AU - Groven, J. AU - Pearce, L. TA - AGU Fall Meeting Abstracts SO - American Geophysical Union, Fall Meeting 2019, abstract #P21C-02 VI - 2019 DP - 2019 Dec 01 PG - P21C-02 4099- https://ui.adsabs.harvard.edu/abs/2019AGUFM.P21C..02S AB - Saturn's largest moon, Titan, hosts a methane-driven hydrological cycle [1-2]. This methane has been in the atmosphere for less than 470 Myr [3]. However, the reservoir that released this methane is poorly understood. Here we show that Titan presently has a bistable climate, and that the atmospheric methane is released during a transition between climatic regimes: from the colder "Slushball Titan" regime (in which all surface methane is sequestered in the depths of a nearly global nitrogen-dominated ocean) to the present warm climatic regime in which nearly all surface methane is atmospheric.

In the Slushball Titan regime, the lack of atmospheric methane results in frigid surface temperatures, well below 84 K [4-5], the tipping point between regimes. Under these conditions, Titan's atmosphere partially collapses into a nearly global ~70 m deep nitrogen ocean. Thermodynamics drive nearly all surface methane (whether atmospheric or geologically released) into this ocean.

We propose that Titan was in a slushball climate until a few hundred Myr ago, until an energetic event (such as a large impact and/or changes in insolation) warmed Titan sufficiently to trigger a transition to the warm Titan climate. This transition would evaporate the nitrogen ocean and release its oceanic methane to the atmosphere. This atmospheric methane would further warm the moon and begin to experience photochemical processing. This scenario is consistent with Titan's surface cratering age (200-1000 Myr; [6]), the ~50-630 Myr required to form Titan's dune materials from atmospheric methane [7], and the ~300-1200 Myr required to explain Titan's global shape via ethane substitution in methane clathrates [8]. This is also consistent with the presence of fluvial features in Titan's low latitudes [9], the lower crater abundance at lower elevations [10], and the overabundance of small craters, which indicate that Titan's atmosphere was thinner in the past [6].

PT - Conference TI - HST Search for Binary Neptune Trojans: Upper Limits and Comparison to Other Transneptunian Populations AU - Noll, Keith AU - Grundy, William TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-2038 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-2038 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13.2038N AB - The Hubble Space Telescope has observed six of the twenty two known Neptune Trojans (NT). The origin of this population is not known and color information suggests it may differ from other transneptunian populations. The frequency of binaries is another observable property that differs among these populations. No binaries have been found among the small sample of NTs observed. The lack of binary NTs is compared to other populations in the same absolute magnitude range. A larger, potentially realizable sample of NTs will be required in order for binary frequency to be a constraining property.

PT - Conference TI - On the Origin of the Remarkable Contact Binary (486958) 2014 MU69 ("Ultima Thule") AU - McKinnon, William B. AU - Keane, James T. AU - Nesvorný, David AU - Richardson, Derek C. AU - Hamilton, Douglas P. AU - Lauer, Tod R. AU - Lisse, Casey M. AU - Mao, Xiaochen AU - Marohnic, Julian AU - Parker, Alex H. AU - Porter, Simon B. AU - Showalter, Mark W. AU - Umurhan, Orkan M. AU - Spencer, John R. AU - Grundy, William M. AU - Moore, Jeffrey M. AU - Stern, S. Alan AU - Weaver, Hal A. AU - Olkin, Catherine B. AU - New Horizons Science Team TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-1387 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-1387 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13.1387M AB - We discuss the remarkable world 2014 MU69, or "Ultima Thule," as revealed by the recent New Horizons flyby. This body reveals hitherto unimagined details of how the building blocks of planets -planetesimals -were actually assembled.

PT - Conference TI - Limits on Rings and Debris Around 2014 MU69 from New Horizons AU - Throop, Henry AU - Lauer, Tod AU - Spencer, John AU - Showalter, Mark AU - Buie, Marc AU - Porter, Simon AU - Grundy, Will AU - Weaver, Harold AU - Stern, S. Alan AU - Hamilton, Doug AU - Kaufmann, David AU - Verbiscer, Anne AU - Zangari, Amanda AU - Olkin, Cathy AU - Parker, Joel TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-1196 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-1196 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13.1196T AB - We searched for rings around 2014MU69 ('Ultima Thule'). We looked extensively, but we found nothing.

PT - Conference TI - Understanding the Hydrocarbon Lakes and Seas on Titan AU - Hanley, Jennifer AU - Engle, Anna AU - Dustrud, Shyanne AU - Groven, Jessica AU - Lindberg, Gerrick AU - Grundy, William AU - Tan, Sugata AU - Tegler, Stephen TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-1146 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-1146 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13.1146H AB - We have performed laboratory experiments and chemical modeling to understand methane and ethane stability in the presence of a nitrogen atmosphere with respect to surface condition on Titan.

PT - Conference TI - Photometric properties of Pluto's main surface units AU - Protopapa, Silvia AU - Olkin, Cathy AU - Grundy, Will AU - Li, Jian-Yang AU - Verbiscer, Anne AU - Cruikshank, Dale P. AU - Howett, Carly J. A. AU - Stern, Alan AU - Weaver, Harold A. AU - Young, Leslie A. AU - Ennico, Kim TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-1026 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-1026 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13.1026P AB - We present a multi-wavelength, regionally dependent photometric analysis of Pluto's surface. We will perform a comparative analysis and use these properties to quantitively infer the composition of Pluto's different terrains and investigate the different coloring agents across Pluto's surface.

PT - Conference TI - Atmosphere/Surface/Subsurface Interaction at Pluto AU - Young, Leslie AU - Tan, Sugata AU - Trafton, Lawence AU - Stansberry, John AU - Grundy, William AU - Protopapa, Silvia AU - Schmitt, Bernard AU - Umurhan, Orkan AU - Bertrand, Tanguy TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-1015 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-1015 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13.1015Y AB - Methane is critical to Pluto's evolution. The methane in Pluto's atmosphere, surface, and subsurface is not in equilibrium. If we understand how and why now, we can extrapolate behavior to other epochs.

PT - Conference TI - New Horizons REX Radiometry at 2014 MU69 AU - Linscott, Ivan AU - Bird, Mike AU - Tyler, Len AU - Patzold, Martin AU - Stern, Alan AU - Weaver, Hal AU - Young, Leslie AU - Olkin, Cathy AU - Moore, Jeff AU - Grundy, Will AU - DeBoy, Chris AU - Sepan, Rebecca AU - Vincent, Michael AU - Bowman, Alice AU - Oudrhiri, Kamal TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-973 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-973 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..973L AB - During the January 1, 2019, encounter with 2014 MU69, the REX instrument on New Horizons measured radio thermal emission at the wavelength of 4.2 cm. Two radiometry observations were conducted, one on approach, and one on departure. Brightness temperature measurements were made of the unresolved disk. An additional bistatic radar experiment was performed during the departure thermal scan.

PT - Conference TI - Pluto surface composition from spectral model inversion with metaheuristics AU - Gabasova, Leila AU - Blanchard, Nikola K. AU - Schmitt, Bernard AU - Grundy, Will M. AU - Olkin, Cathy B. AU - Spencer, John R. AU - Young, Leslie A. AU - Ennico Smith, Kimberly AU - Weaver, Hal A. AU - Stern, S. Alan TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-968 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-968 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..968G AB - We present first quantitative results for the composition of Pluto's surface from New Horizons LEISA data, achieved using radiative transfer model inversion via progressive metaheuristic methods. We discuss the implications of these results as regards other New Horizons datasets for Pluto's surface, and introduce new methods for pixel-by-pixel mapping and segmentation in order to create a global quantitative compositional map.

PT - Conference TI - Rapid Temporal Variability of Condensed Oxygen on Europa? AU - Spencer, John AU - Grundy, William AU - Schmidt, Carl TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-935 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-935 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..935S AB - New visible-wavelength spectroscopy of Europa provides the best view so far of the enigmatic 0.3% deep 5770 A absorption feature due to condensed O2. The band depth is inconsistent in observations of the same longitude on Europa taken a week apart, which if real implies surprisingly rapid temporal variability. Additional observations are being obtained to further test the reality of these rapid changes.

PT - Conference TI - Testing tholins as analogs of the dark reddish material covering the cthulhu region. AU - Fayolle, Marie AU - Quirico, Eric AU - Schmitt, Bernard AU - Jovanovic, Lora AU - Gautier, Thomas AU - Carrasco, Nathalie AU - Grundy, William AU - Vuitton, Veronique AU - Poch, Olivier AU - Gabasova, Leila AU - Protopapa, Silvia AU - Young, Leslie TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-876 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-876 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..876F AB - We report on the determination of the optical properties of dusty tholins, which have been used in Hapke models to fit MVIC/LEISA data collected by the New Horizons spacecraft. We show a mismatch between models and observations, which is best explained by the presence of a highly porous organic material.

PT - Conference TI - Stereo Topography of KBO (486958) 2014 MU69 AU - Beyer, Ross AU - Porter, Simon AU - Schenk, Paul AU - Spencer, John AU - Beddingfield, Chloe AU - Grundy, William AU - Keane, James AU - Lauer, Tod AU - Moore, Jeff AU - Olkin, Catherine AU - Parker, Joel AU - Stern, Alan AU - Umurhan, Orkan AU - Verbiscer, Anne AU - Weaver, Harold TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-849 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-849 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..849B AB - We describe stereo topography of KBO MU69. We detail the New Horizons observations that were used to produce the topography, characteristics of the resulting model, and its relation to the whole body shape model derived by other means.

PT - Conference TI - The Solar System Origins Legacy Survey: Motivation, Design, and Initial Results AU - Parker, Alex AU - Porter, Simon AU - Kavelaars, Jj AU - Benecchi, Susan AU - Bannister, Michele AU - Noll, Keith AU - Grundy, Will TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-768 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-768 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..768P AB - The Solar System Origins Legacy Survey (SSOLS) is a very large Hubble Space Telescope program designed to test predictions about the formation and evolution of primordial planetesimals. It will do this by conducting a carefully calibrated search for binary systems in the Cold Classical Kuiper Belt, with over 200 objects to be observed.

PT - Conference TI - Manwë -Thorondor: A tertiary system in the Kuiper Belt? AU - Rabinowitz, David AU - Benecchi, Susan AU - Grundy, William AU - Porter, Simon AU - Thirouin, Audrey AU - Verbiscer, Anne TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-759 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-759 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..759R AB - We present light-curve observations of the binary Kuiper Belt object (385446) Manwë-Thorondor. The system is currently undergoing mutual events whereby the two bodies alternately eclipse and occult each other several times per year. Our observations suggest this system may be composed of three bodies. The primary (Manwë) may be a contact binary similar in shape to (but larger than) Ultima-Thule, the Kuiper-Belt object recently encountered by NASA's New Horizons spacecraft. The secondary (Thorondor) may be rotating extremely slowly ( 1 year period) and have a highly elongated shape. The unusual rotation of Thorondor would likely result from dynamical interactions between Manwe and Thorondor, which are unusually strong given the high eccentricity of their mutual orbit.

PT - Conference TI - Near surface temperature modelling of 2014 MU_69 AU - Umurhan, Orkan M. AU - Keane, James T. AU - Porter, Simon B. AU - Linscott, Ivan AU - Grundy, William M. AU - Young, Leslie A. AU - Beyer, Ross A. AU - Bierson, Carver AU - Spencer, John R. AU - Stern, S. Alan AU - Weaver, Hal. A. AU - Olkin, Catherine B. AU - Parker, Joel W. AU - Verbiscer, Anne J. TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-749 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-749 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..749U AB - New Horizons REX radiometer observed of the small Kuiper Belt Object 2014 MU69 at relatively high phase angle and measured a disk averaged brightness temperature of about 23 K. In this study, we perform a thermophysical analysis of the body to better understand this radio observation. We find for assumed thermophysical parameters, the REX radiometer may have been observing about 0.5 meters beneath MU69's surface.

PT - Conference TI - The Color of 2014 MU69 from New Horizons AU - Olkin, Catherine AU - Stern, S. Alan AU - Spencer, John AU - Weaver, Hal AU - Howett, Carly AU - Parker, Alex AU - Grundy, Will AU - Protopapa, Silvia TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-639 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-639 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..639O AB - This paper presents the color of MU69.

PT - Conference TI - New Horizons REX Radiometry at Pluto and Charon AU - Bird, Michael AU - Linscott, Ivan AU - Hinson, David AU - Tyler, Len AU - Strobel, Darrell AU - Pätzold, Martin AU - Summers, Michael AU - Stern, Alan AU - Weaver, Hal AU - Young, Leslie AU - Ennico, Kimberly AU - Gladstone, Randy AU - Olkin, Cathy AU - Moore, Jeff AU - Grundy, Will AU - DeBoy, Chris AU - Vincent, Michael TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-413 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-413 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..413B AB - The thermal radio emission at 4.2 cm from Pluto and Charon was measured by radiometry observations as part of the REX investigation on New Horizons. As expected from its higher optical albedo, Charon was determined to be distinctly warmer than Pluto. The thermal emission from the dayside of both bodies was found to be stronger than on the nightside.

PT - Conference TI - The Shape and Pole of (486958) 2014 MU69 AU - Porter, Simon AU - Beyer, Ross AU - Keane, James AU - Umurhan, Orkan AU - Bierson, Carver AU - Grundy, William AU - Buie, Marc AU - Showalter, Mark AU - Spencer, John AU - Stern, Alan AU - Weaver, Hal AU - Olkin, Catherine AU - Parker, Joel AU - Verbiscer, Anne TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-311 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-311 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..311P AB - NASA's New Horizons spacecraft flew past the cold classical Kuiper Belt Object (KBO) 2014 MU69, providing the first opportunity to see a KBO up close. We will present our initial results on the shape and pole fitting of MU69, showing its contact-binary shape, highly-inclined pole, and the implications for KBO formation.

PT - Conference TI - Pluto dark refractory material: a close look at composition and origin AU - Dalle Ore, Cristina AU - Cruikshank, Dale P. AU - Protopapa, Silvia AU - Grundy, Will M. AU - Ennico, Kim AU - Olkin, Cathy B. AU - Stern, S. Alan AU - Weaver, Hal A. AU - Young, Leslie A. TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-207 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-207 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..207D AB - We examine a few regions of interest (ROIs) from the high spatial resolution scan obtained with the Linear Etalon Imaging Spectral Array (LEISA) during the July 2015 New Horizons Pluto flyby. We focus on the dark material that distinguishes the equatorial region known as Cthulhu and compare and contrast its signature as the H2O component varies in either abundance or grain size. Our goal is to trace the origin of the material and constrain its mechanisms of formation.

PT - Conference TI - Scarp Retreat on MU69: Evidence and Implications for Composition and Structure AU - Moore, Jeffrey M. AU - McKinnon, William B. AU - Spencer, John R. AU - Stern, S. Alan AU - Britt, Daniel AU - Buratti, Bonnie J. AU - Grundy, William M. AU - Porter, Simon B. AU - Schenk, Paul M. AU - Singer, Kelsi N. AU - Weaver, Harold A. AU - Parker, Joel W. AU - Verbiscer, Anne J. AU - Beyer, Ross A. AU - Dhingra, Rajani D. AU - Keane, James T. AU - Lauer, Tod R. AU - Lisse, Carey M. AU - Umurhan, Orkan M. AU - White, Oliver L. TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-50 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-50 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13...50M AB - Crenulated scarps and other unit boundary patterns are consistent with scarp retreat. If indeed scarps have retreated on MU69 the most likely process is sublimation degradation. This explanation has implications for both original volatile composition and structure (layering) of MU69.

PT - Conference TI - Testing Tholins as Analogs of the Dark Reddish Material Covering the Cthulhu Region AU - Fayolle, M. AU - Quirico, E. AU - Schmitt, B. AU - Jovanovic, L. AU - Gautier, T. AU - Carrasco, N. AU - Grundy, W. AU - Vuitton, V. AU - Poch, O. AU - Gabasova, L. AU - Protopapa, S. AU - Young, L. TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7075 VI - 2133 DP - 2019 Jul 01 PG - 7075 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7075F AB - Optical properties of dust tholins have been determined in the laboratory and used to feed Hapke models. Fitting MVIC/LEISA data of the Cthulhu region reveals that the dark reddish material is likely highly porous, or may have been processed by GCR.

PT - Conference TI - Pluto Dark Refractory Material: A Close Look at Composition and Origin AU - Dalle Ore, C. M. AU - Cruikshank, D. P. AU - Protopapa, S. AU - Grundy, W. M. AU - Olkin, C. B. AU - Stern, S. A. AU - Weaver, H. A. AU - Young, L. A. AU - New Horizons Composition Team TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7073 VI - 2133 DP - 2019 Jul 01 PG - 7073 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7073D AB - We investigate the dark refractory constituent that distinguishes Cthulhu and compare and contrast its signature as the H2O component varies. Our goal is to trace the origin of the material and constrain its mechanisms of formation.

PT - Conference TI - Observations of Pluto's Surface with ALMA AU - Butler, B. J. AU - Grundy, W. M. AU - Gurwell, M. A. AU - Lellouch, E. AU - Moreno, R. AU - Moullet, A. AU - Young, L. A. TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7058 VI - 2133 DP - 2019 Jul 01 PG - 7058 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7058B AB - We will describe long-wavelength ( 1mm) observations of Pluto with ALMA. Observations were carried out at three longitudes, with enough resolution to easily resolve Pluto. At least one brightness temperature enhancement is seen, near Piri Planitia.

PT - Conference TI - Beyond Pluto: The New Horizons Encounter with Kuiper Belt Object 2014 MU69 AU - Spencer, J. R. AU - Stern, S. A. AU - Weaver, H. A. AU - Olkin, C. B. AU - Moore, J. M. AU - Grundy, W. M. AU - McKinnon, W. B. AU - New Horizons Science Team TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7057 VI - 2133 DP - 2019 Jul 01 PG - 7057 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7057S AB - The New Horizons flyby of the KBO 2014 MU69 gave the first close-up view of a member of the Cold Classical Kuiper Belt, the most primitive population of small bodies in the solar system. MU69 is a contact binary unlike anything previously seen.

PT - Conference TI - Photometric Properties of Pluto's Main Surface Units AU - Protopapa, S. AU - Olkin, C. AU - Grundy, W. AU - Li, J. Y. AU - Verbiscer, A. AU - Cruikshank, D. P. AU - Howett, C. J. A. AU - Stern, A. AU - Weaver, H. A. AU - Young, L. A. TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7054 VI - 2133 DP - 2019 Jul 01 PG - 7054 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7054P AB - We present a multi-wavelength, regionally dependent photometric analysis of Pluto's surface. We will use these properties to quantitively infer the composition of Pluto's different terrains.

PT - Conference TI - Pluto's Surface Composition AU - Grundy, W. M. AU - Cruikshank, D. P. AU - Protopapa, S. AU - Schmitt, B. TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7051 VI - 2133 DP - 2019 Jul 01 PG - 7051 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7051G AB - Pluto's surface composition is regionally heterogeneous. Volatile ices of N2, CO, and CH4 are mobile on seasonal timescales, interacting with and even sculpting more inert materials such as H2O, NH3, CH3OH, and complex organics.

PT - Conference TI - Charon's Surface Composition AU - Cook, J. C. AU - Protopapa, S. AU - Cruikshank, D. P. AU - Dalle Ore, C. M. AU - Grundy, W. M. TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7049 VI - 2133 DP - 2019 Jul 01 PG - 7049 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7049C AB - This is an invited talk to give a review of what is known about the surface composition of Charon.

PT - Conference TI - The Colors and Photometric Properties of Pluto AU - Olkin, C. B. AU - Howett, C. J. A. AU - Protopapa, S. AU - Grundy, W. M. AU - Buie, M. W. AU - Verbiscer, A. AU - Stern, S. A. AU - Weaver, H. A. AU - Young, L. A. AU - Ennico, K. TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7045 VI - 2133 DP - 2019 Jul 01 PG - 7045 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7045O AB - This paper will focus on our new understanding of the color of Pluto's surface from the New Horizons mission results. Different terrain units will be discussed. Also an overview of the photometric properties of Pluto's surface will be presented.

PT - Conference TI - Volatile and Climate Cycles on Short and Long Timescales AU - Earle, A. M. AU - Binzel, R. P. AU - Young, L. A. AU - Bertrand, T. AU - Buie, M. W. AU - Cruikshank, D. P. AU - Ennico, K. S. AU - Forget, F. AU - Grundy, W. M. AU - Moore, J. M. AU - Olkin, C. B. AU - Schmitt, B. AU - Spencer, J. R. AU - Stansberry, J. A. AU - Stern, S. A. AU - Trafton, L. M. AU - Umurhan, O. M. AU - Weaver, H. A. AU - New Horizons Science Team TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7044 VI - 2133 DP - 2019 Jul 01 PG - 7044 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7044E AB - This talk will explore Pluto's insolation history and its implications for Pluto's atmospheric pressure, surface temperatures, and volatile distributions over various timescales.

PT - Conference TI - Pluto Data Before and After New Horizons: The Takeaway for Future Observations AU - Dalle Ore, C. M. AU - Barucci, M. A. AU - Fornasier, S. AU - Cruikshank, D. P. AU - Grundy, W. M. AU - Protopapa, S. TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7040 VI - 2133 DP - 2019 Jul 01 PG - 7040 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7040D AB - We present what we have learned in the comparison of observations of Pluto taken before and after New Horizons, and we draw conclusions on how we should proceed with future observation planning of TNOs.

PT - Conference TI - On the Disequilibrium of Pluto's Volatiles AU - Young, L. A. AU - Tan, S. P. AU - Trafton, L. M. AU - Stansberry, J. A. AU - Grundy, W. B. AU - Protopapa, S. AU - Schmitt, B. AU - Umurhan, O. M. AU - Bertrand, T. TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7039 VI - 2133 DP - 2019 Jul 01 PG - 7039 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7039Y AB - The volatiles present as ices on Pluto's surface and in its atmosphere are in state of disequilibrium. There is new work on predicted equilibrium, drivers to disequilibrium, and relaxation timescales.

PT - Conference TI - The Shapes and Poles of Nix and Hydra from New Horizons AU - Porter, S. B. AU - Showalter, M. R. AU - Weaver, H. A. AU - Spencer, J. R. AU - Lauer, T. R. AU - Verbiscer, A. J. AU - Grundy, W. M. AU - Stern, S. A. AU - Young, L. A. AU - Olkin, C. B. AU - Ennico, K. TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7038 VI - 2133 DP - 2019 Jul 01 PG - 7038 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7038P AB - Four small satellites Regular in orbit but not shape Spinning fast.

PT - Conference TI - Geology of Charon AU - Beyer, R. A. AU - Spencer, J. AU - Robbins, S. AU - Singer, K. AU - Beddingfield, C. AU - Grundy, W. AU - Ennico, K. AU - Keane, J. AU - McKinnon, W. AU - Moore, J. AU - Nimmo, F. AU - Olkin, C. AU - Runyon, K. AU - Schenk, P. AU - Stern, A. AU - Weaver, H. AU - Young, L. AU - New Horizons Science Team TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7035 VI - 2133 DP - 2019 Jul 01 PG - 7035 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7035B AB - Charon is a geologically complex world, different in character from Pluto. Charon shows signs of tectonic disruption and large scale resurfacing, consistent with an ancient global ocean, now frozen.

PT - Conference TI - Global Compositional Cartography of Pluto from LEISA Data AU - Gabasova, L. R. AU - Schmitt, B. AU - Grundy, W. AU - Olkin, C. B. AU - Spencer, J. R. AU - Young, L. A. AU - Ennico, K. AU - Weaver, H. A. AU - Stern, S. A. AU - New Horizons Composition Team TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7029 VI - 2133 DP - 2019 Jul 01 PG - 7029 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7029G AB - We use intensity-based registration methods to co-register high- resolution LEISA data with lower-resolution imagery taken during the approach to Pluto, and produce the first global compositional maps of Pluto's surface.

PT - Conference TI - Pluto's Small Satellites AU - Weaver, H. A. AU - Porter, S. B. AU - Buie, M. W. AU - Cook, J. C. AU - Grundy, W. M. AU - Verbiscer, A. J. AU - Hamilton, D. P. AU - Lauer, T. R. AU - Showalter, M. R. AU - Spencer, J. R. AU - Stern, S. A. AU - Ennico, K. AU - Olkin, C. B. AU - Young, L. A. AU - New Horizons Science Team TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7028 VI - 2133 DP - 2019 Jul 01 PG - 7028 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7028W AB - In this invited talk, we review the properties of the small satellites and how they inform our understanding of the origin of the Pluto system.

PT - Conference TI - Pluto's Far Side AU - Stern, S. A. AU - Weaver, H. A. AU - Young, L. A. AU - Olkin, C. B. AU - Moore, J. M. AU - Grundy, W. M. AU - McKinnon, W. B. AU - Lauer, T. R. AU - Cruikshank, D. P. AU - Spencer, J. R. AU - Gladstone, G. R. AU - Ennico, K. AU - New Horizons Science Team TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7024 VI - 2133 DP - 2019 Jul 01 PG - 7024 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7024S AB - This session will review all we know about the "far side" of Pluto based on the datasets obtained by New Horizons. We will also review future opportunities to advance the study of the far side over the next few decades.

PT - Conference TI - Cryovolcanism on Pluto AU - Cruikshank, D. P. AU - Umurhan, O. M. AU - Beyer, R. A. AU - Schmitt, B. AU - Keane, J. T. AU - Runyon, K. D. AU - Atri, D. AU - White, O. L. AU - Matsuyama, I. AU - Moore, J. M. AU - Sandford, S. A. AU - Singer, K. N. AU - Grundy, W. M. AU - Dalle Ore, C. M. AU - Cook, J. C. AU - Bertrand, T. AU - Stern, S. A. AU - Olkin, C. B. AU - Weaver, H. A. AU - Young, L. A. AU - Spencer, J. R. AU - Lisse, C. M. AU - Pendleton, Y. J. AU - Binzel, R. P. AU - Earle, A. M. AU - Robbins, S. J. AU - Gladstone, G. R. AU - Schenk, P. M. AU - Cartwright, R. J. AU - McKinnon, W. B. AU - Ennico, K. AU - Scipioni, F. TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7020 VI - 2133 DP - 2019 Jul 01 PG - 7020 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7020C AB - Geological and compositional evidence indicate relatively recent (less than 10^9 y) cryovolcanic activity in Virgil Fossae and in Viking Terra.

PT - Conference TI - Radio Science Experiment (REX) on New Horizons: Results from the Pluto Flyby AU - Bird, M. K. AU - Linscott, I. R. AU - Hinson, D. P. AU - Tyler, G. L. AU - Strobel, D. F. AU - Pätzold, M. AU - Summers, M. E. AU - Hahn, M. AU - Andert, T. P. AU - Stern, S. A. AU - Weaver, H. A. AU - Young, L. A. AU - Ennico, K. AU - Gladstone, G. R. AU - Olkin, C. B. AU - Moore, J. M. AU - Grundy, W. M. AU - DeBoy, C. C. AU - Vincent, M. TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7018 VI - 2133 DP - 2019 Jul 01 PG - 7018 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7018B AB - Summaries of the REX investigations during the Pluto flyby, including an atmospheric radio occultation, radio thermal emission measurements, a bistatic radar experiment, and a system mass determination, are presented.

PT - Conference TI - Charon's Colors and Photometric Properties AU - Howett, C. J. A. AU - Olkin, C. B. AU - Protopapa, S. AU - Grundy, W. M. AU - Verbiscer, A. AU - Buratti, B. J. TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7015 VI - 2133 DP - 2019 Jul 01 PG - 7015 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7015H AB - This paper is an overview of Charon's global and regional colors, and its photometric properties.

PT - Conference TI - Methane Stratification on Pluto Inferred from New Horizons LEISA Data AU - Schmitt, B. AU - Gabasova, L. AU - Bertrand, T. AU - Grundy, W. AU - Stansberry, J. AU - Lewis, B. AU - Protopapa, S. AU - Young, L. AU - Olkin, C. AU - Reuter, D. AU - Stern, A. AU - Weaver, H. TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7004 VI - 2133 DP - 2019 Jul 01 PG - 7004 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7004S AB - We show that the relative intensity of the CH4 band depth reflect a stratification of CH4. The stratification of CH4 is shown to result from the differential sublimation between N2 and CH4 which tends to concentrate CH4 in N2 ice grains.

PT - Journal Article TI - Mars Exploration Rover Pancam Spectrophotometric Modeling: The Final Chapter AU - Johnson, J. R. AU - Bell, J. F. AU - Lemmon, M. AU - Grundy, W. AU - Liang, W. AU - Hayes, A. AU - Deen, R. TA - LPI Contributions SO - Ninth International Conference on Mars, held 22-25 July, 2019 in Pasadena, California. LPI Contribution No. 2089, id.6083 VI - 2089 DP - 2019 Jul 01 PG - 6083 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2089.6083J AB - Pancam multiple time-of-day multispectral visible/near-infrared images acquired by Spirit near Troy and by Opportunity on northern Cape York enabled photometric modeling of airfall dust deposits and the effects of dusty windows on model parameters.

PT - Conference TI - Shape of 2014 MU69: Contact Binary from Low Speed Merger? AU - Cheng, A. F. AU - Weaver, H. A. AU - Stern, S. A. AU - McKinnon, W. B. AU - Moore, J. M. AU - Runyon, K. D. AU - Grundy, W. AU - Olkin, C. B. AU - Spencer, J. R. AU - Verbiscer, A. J. AU - Parkrer, J. W. AU - Lisse, C. M. TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.3273 DP - 2019 Mar 01 PG - 3273 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.3273C AB - The shape of 2014 MU69 suggests a contact binary formed in a low speed merger, and the merger speed may be 1 m/s.

PT - Conference TI - Using Computer-Generated Imagery (CGI) for Science and Outreach on Missions: New Horizons' Encounter with the Pluto-Charon System and (486958) 2014 MU69 AU - Robbins, S. J. AU - Keane, J. T. AU - Kinczyk, M. AU - Runyon, K. AU - Beddingfield, C. B. AU - Beyer, R. A. AU - Grundy, W. M. AU - Moore, J. M. AU - McKinnon, W. B. AU - Schenk, P. M. AU - Lauer, T. R. AU - Binzel, R. P. AU - Verbiscer, A. AU - Parker, J. AU - Olkin, C. B. AU - Weaver, H. A. AU - Spencer, J. R. AU - Stern, S. A. AU - NH Geology, Geophysics, Imaging Science Theme Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.3057 DP - 2019 Mar 01 PG - 3057 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.3057R AB - CGI is an / Important tool for our use / Stand with fed. workers.

PT - Conference TI - Comparing (486958) 2014 MU69 to Cometary Nuclei: Shapes and Surfaces AU - Weaver, H. A. AU - Stern, S. A. AU - Britt, D. T. AU - Buratti, B. J. AU - Cheng, A. F. AU - Lisse, C. M. AU - Grundy, W. AU - McKinnon, W. B. AU - Parker, J. Wm. AU - Protopapa, S. AU - Robbins, S. J. AU - Schenk, P. M. AU - Singer, K. N. AU - Olkin, C. B. AU - Spencer, J. R. AU - Moore, J. M. AU - Barnouin, O. S. AU - Bierson, C. J. AU - Buie, M. W. AU - Lauer, T. R. AU - El-Maarry, M. R. AU - Ernst, C. M. AU - Porter, S. B. AU - Reuter, D. C. AU - Runyon, K. D. AU - Umurhan, O. M. AU - Verbiscer, A. J. AU - Zangari, A. M. AU - New Horizons Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2982 DP - 2019 Mar 01 PG - 2982 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2982W AB - MU69 vs. Cometary Nuclei: Comparisons of shapes and surfaces.

PT - Conference TI - New Horizons Observations of Distant Kuiper Belt Objects: Rotational and Solar Phase Curves of (486958) 2014 MU69 and Other Cold Classical KBOs AU - Verbiscer, A. J. AU - Porter, S. B. AU - Benecchi, S. D. AU - Kavelaars, J. J. AU - Weaver, H. A. AU - Spencer, J. R. AU - Buie, M. W. AU - Buratti, B. J. AU - Helfenstein, P. AU - Parker, A. H. AU - Zangari, A. M. AU - Hofgartner, J. D. AU - Howett, C. J. A. AU - Dalle Ore, C. M. AU - Protopapa, S. AU - Grundy, W. AU - Olkin, C. B. AU - Parker, J. W. AU - Stern, S. A. AU - New Horizons GGI Team AU - New Horizons Composition Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2959 DP - 2019 Mar 01 PG - 2959 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2959V AB - Kuiper belt objects / Scatter feeble sunlight to / Show surface texture.

PT - Conference TI - Highly Localized Seasonal Cold-Trapping in the Neck of 2014 MU69 'Ultima Thule' AU - Binzel, R. P. AU - Earle, A. M. AU - Grundy, W. M. AU - Moore, J. M. AU - Stern, S. A. AU - Spencer, J. R. AU - Young, L. A. AU - Olkin, C. B. AU - Parker, J. W. AU - Verbiscer, A. J. AU - Weaver, H. A. AU - Cheng, A. AU - Reuter, D. C. AU - Buie, M. W. AU - Cruikshank, D. P. AU - Stansberry, J. A. AU - Schmitt, B. AU - McKinnon, W. B. AU - Schenk, P. M. AU - Lisse, C. M. AU - Zangari, A. M. AU - Keane, J. T. AU - Umurhan, O. M. AU - Britt, D. AU - Bagenal, F. AU - New Horizons Geology AU - Geophysics Team AU - New Horizons Composition Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2933 DP - 2019 Mar 01 PG - 2933 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2933B AB - Cold trapping in the 'crevasse' of the neck, seasonally shadowed by the lobes of Ultima Thule, could be responsible for the sharply delineated bright "collar."

PT - Conference TI - Comets Sourced by KBOs - Comparison of SFDs Derived from Spitzer/Wise JFC Imaging and Pluto and Charon KBO Cratering Rates AU - Lisse, C. M. AU - Singer, K. N. AU - Fernandez, Y. R. AU - Bauer, J. M. AU - Protopapa, S. AU - Cheng, A. F. AU - Weaver, H. A. AU - McKinnon, W. B. AU - Kaevelars, J. J. AU - Stern, S. A. AU - Spencer, J. R. AU - Olkin, C. B. AU - Parker, J. Wm. AU - Moore, J. M. AU - Umurhan, O. M. AU - Grundy, W. M. AU - Young, L. A. AU - Verbiscer, A. AU - New Horizons GGI Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2865 DP - 2019 Mar 01 PG - 2865 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2865L AB - Spitzer/WISE JF comet and new NH Pluto/Charon KBO size-frequency distributions are similar; another piece of evidence that the populations are genetically linked.

PT - Conference TI - Ultima Thule, TNOs ,and the Irregular Satellites of the Outer Planets: Spectroscopic and Color Comparison AU - Scipioni, F. AU - Dalle Ore, C. M. AU - Grundy, W. M. AU - Cruikshank, D. P. AU - Cook, J. C. AU - Earle, A. M. AU - Protopapa, S. AU - Schmitt, B. AU - Quirico, E. AU - Olkin, C. B. AU - Howett, C. J. A. AU - Binzel, R. P. AU - Parker, A. H. AU - Reuter, D. C. AU - Stern, S. A. AU - Spencer, J. R. AU - Verbiscer, A. J. AU - Weaver, H. A. AU - Kavelaars, J. J. AU - Britt, D. T. AU - New Horizons Composition Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2843 DP - 2019 Mar 01 PG - 2843 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2843S AB - We present a comparison of the colors and the spectrum of 2014 MU69 with those known TNOs, and of the irregular satellites of Saturn, Uranus, and Neptune.

PT - Conference TI - Comparison of Near Infrared Spectra Between Pluto-System Objects and 486958 2014 MU69: Analysis of New Horizons Spectral Images AU - Cook, J. C. AU - Dalle Ore, C. M. AU - Scipioni, F. AU - Cruikshank, D. P. AU - Grundy, W. M. AU - Protopapa, S. AU - Binzel, R. P. AU - Britt, D. T. AU - Earle, A. M. AU - Gabasova, L. AU - Howett, C. AU - Jennings, D. J. AU - Kavalaars, J. J. AU - Lunsford, A. W. AU - Olkin, C. B. AU - Parker, A. H. AU - Parker, J. W. AU - Quirico, E. AU - Reuters, D. AU - Schmitt, B. AU - Spencer, J. R. AU - Stern, S. A. AU - Verbiscer, A. J. AU - Weaver, H. A. TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2818 DP - 2019 Mar 01 PG - 2818 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2818C AB - We compare New Horizons LEISA spectra of 2014 MU69 to sites and objects in the Pluto system, specifically we compare to Nix and Cthulhu Regio, on Pluto.

PT - Conference TI - Ultima Thule: Possible Gravitational Collapse Scenarios for its Origin AU - Umurhan, O. M. AU - Kavelaars, J. J. AU - Cuzzi, J. N. AU - McKinnon, W. B. AU - Lyra, W. AU - Hartlep, T. AU - Hofgartner, J. AU - Showalter, M. R. AU - Estrada, P. R. AU - Bierson, C. J. AU - Dhingra, R. D. AU - Keane, J. T. AU - White, O. L. AU - Grundy, W. AU - Moore, J. M. AU - Verbiscer, A. AU - Parker, J. AU - Olkin, C. B. AU - Weaver, H. A. AU - Spencer, J. R. AU - Stern, S. A. TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2809 DP - 2019 Mar 01 PG - 2809 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2809U AB - What are the possible gravitational collapse scenarios to explain the origin of Ultima Thule? The answer hinges on the protoplanetary disk's turbulent state.

PT - Conference TI - Color and Albedo of Ultima Thule: A Comparison to TNOs and Centaurs AU - Dalle Ore, C. M. AU - Cruikshank, D. P. AU - Scipioni, F. AU - Cartwright, R. J. AU - Binzel, R. P. AU - Earle, A. M. AU - Kavelaars, J. J. AU - Protopapa, S. AU - Cook, J. C. AU - Olkin, C. B. AU - Grundy, W. M. AU - Howett, C. J. A. AU - Parker, A. H. AU - Britt, D. T. AU - Stern, S. A. AU - Spencer, J. R. AU - Weaver, H. A. AU - Parker, J. Wm. AU - Verbiscer, A. J. AU - New Horizons Composition Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2770 DP - 2019 Mar 01 PG - 2770 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2770D AB - We compare photometric data for 486958 2014 MU69 with respect to similar objects to investigate the dynamical and chemical evolution of the outer solar system.

PT - Conference TI - A Pristine "Contact Binary" in the Kuiper Belt: Implications from the New Horizons Encounter with 2014 MU69 ("Ultima Thule") AU - McKinnon, W. B. AU - Stern, S. A. AU - Weaver, H. A. AU - Spencer, J. R. AU - Buie, M. W. AU - Beyer, R. A. AU - Bierson, C. J. AU - Binzel, R. P. AU - Britt, D. AU - Cruikshank, D. P. AU - Hamilton, D. P. AU - Howett, C. J. A. AU - Keane, J. T. AU - Lauer, T. R. AU - Kavelaars, J. J. AU - Parker, A. H. AU - Parker, J. W. AU - Porter, S. B. AU - Robbins, S. J. AU - Schenk, P. M. AU - Showalter, M. R. AU - Singer, K. N. AU - Umurhan, O. M. AU - White, O. L. AU - Moore, J. M. AU - Grundy, W. M. AU - Gladstone, G. R. AU - Olkin, C. B. AU - Verbiscer, A. J. AU - New Horizons Science Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2767 DP - 2019 Mar 01 PG - 2767 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2767M AB - MU69's contact binary shape provides the clearest view to date of the accretion processes operative in the protosolar nebula and subsequent planetesimal disk.

PT - Conference TI - The Search for Moons and Rings of 2014 MU69 AU - Spencer, J. R. AU - Showalter, M. R. AU - Lauer, T. R. AU - Buie, M. W. AU - Porter, S. B. AU - Throop, H. B. AU - Grundy, W. M. AU - Weaver, H. A. AU - Stern, S. A. AU - Hamilton, D. P. AU - Kaufmann, D. E. AU - Verbiscer, A. J. AU - Zangari, A. M. AU - Olkin, C. B. AU - Parker, J. W. AU - Nh Geology, Geophysics, AU - Imaging Team AU - New Horizons Lorri Team AU - New Horizons Ralph Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2737 DP - 2019 Mar 01 PG - 2737 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2737S AB - New Horizons conducted extensive searches for rings and moons during its flyby of 2014 MU69. As of the time of writing, none have been found.

PT - Conference TI - Comparing Ultima Thule with Comet Nuclei: Colors and Composition AU - Protopapa, S. AU - Grundy, W. M. AU - Olkin, C. B. AU - Howett, C. J. A. AU - Parker, A. H. AU - Weaver, H. A. AU - Stern, S. A. AU - Parker, J. Wm. AU - Lisse, C. M. AU - Britt, D. T. AU - Earle, A. M. AU - Cook, J. C. AU - Cruikshank, D. P. AU - Dalle Ore, C. M. AU - Lunsford, A. W. AU - Quirico, E. AU - Reuter, D. C. AU - Schmitt, B. AU - Scipioni, F. AU - Binzel, R. P. AU - Buie, M. W. AU - Jennings, D. E. AU - Linscott, I. E. AU - Spencer, J. R. AU - Verbiscer, A. J. AU - Young, L. A. AU - Davidsson, B. AU - Li, J. -Y. TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2732 DP - 2019 Mar 01 PG - 2732 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2732P AB - We compare the composition of 2014MU69 with that of comets to determine which features of comets are primitive and which have emerged because of their history.

PT - Conference TI - Intensity-Based Registration for Planetary Cartography: Application to New Horizons LEISA Approach Scans of Pluto AU - Gabasova, L. R. AU - Schmitt, B. AU - Grundy, W. AU - Olkin, C. B. AU - Young, L. A. AU - Ennico, K. AU - Weaver, H. A. AU - Stern, S. A. AU - New Horizons Composition Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2638 DP - 2019 Mar 01 PG - 2638 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2638G AB - With wisdom borrowed / From our medical colleagues / Pluto gets full maps.

PT - Conference TI - Identifying the Solid Phases of Ethane Using Raman Spectroscopy at Conditions Relevant to Titan's Surface AU - Engle, A. AU - Hanley, J. AU - Grundy, W. M. AU - Dustrud, S. AU - Lindberg, G. E. AU - Tegler, S. C. TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2509 DP - 2019 Mar 01 PG - 2509 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2509E AB - Investigating pure ethane at temperatures relevant to Titan's surface to understand how the solid phases may impact the environment.

PT - Conference TI - Spectral Properties of 486958 2014MU69 (Ultima Thule) Versus 67P/Churyumov- Gerasimenko AU - Quirico, E. AU - Schmitt, B. AU - Gabasova, L. AU - Grundy, W. M. AU - Cook, J. C. AU - Protopapa, S. AU - Cruikshank, D. P. AU - Scipioni, F. AU - DalleOre, M. C. AU - Earle, A. M. AU - Olkin, C. B. AU - Howett, C. J. A. AU - Binzel, R. P. AU - Britt, D. AU - Kavelaars, J. J. AU - Parker, A. H. AU - Parker, J. W. AU - Reuter, D. AU - Stern, S. A. AU - Spencer, J. R. AU - Verbiscer, A. J. AU - Weaver, H. A. AU - Young, L. A. AU - New Horizons Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2487 DP - 2019 Mar 01 PG - 2487 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2487Q AB - Here we compare LEISA and MVIC/RALPH spectrophotometric data of MU69 with VIRTIS-M data collected for comet 67P/CG.

PT - Conference TI - 486958 2014 MU69 Ultima Thule Surface Composition Overview AU - Grundy, W. M. AU - Binzel, R. P. AU - Britt, D. T. AU - Buie, M. W. AU - Cook, J. C. AU - Cruikshank, D. P. AU - Dalle Ore, C. M. AU - Earle, A. M. AU - Gabasova, L. AU - Jennings, D. E. AU - Howett, C. J. A. AU - Kavelaars, J. J. AU - Linscott, I. E. AU - Olkin, C. B. AU - Parker, A. H. AU - Parker, J. W. AU - Quirico, E. AU - Protopapa, S. AU - Reuter, D. C. AU - Robbins, S. J. AU - Schmitt, B. AU - Scipioni, F. AU - Singer, K. N. AU - Spencer, J. R. AU - Stansberry, J. A. AU - Stern, S. A. AU - Verbiscer, A. J. AU - Weaver, H. A. AU - Young, L. A. TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2473 DP - 2019 Mar 01 PG - 2473 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2473G AB - Overview of compositional results from the New Horizons encounter with the small, Cold Classical Kuiper belt object (486958) 2014 MU69 "Ultima Thule."

PT - Conference TI - Generating a 3D Shape Model of 2014 MU69 for Scientific Visualization and Public Outreach AU - Kinczyk, M. J. AU - Runyon, K. AU - Robbins, S. J. AU - Keane, J. T. AU - Grundy, W. M. AU - Throop, H. B. AU - Bierson, C. J. AU - Beddingfield, C. B. AU - Beyer, R. A. AU - White, O. L. AU - Moore, J. M. AU - Schenk, P. AU - Lauer, T. R. AU - McKinnon, W. B. AU - Verbiscer, A. AU - Parker, J. AU - Olkin, C. B. AU - Weaver, H. A. AU - Spencer, J. R. AU - Stern, S. A. TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2456 DP - 2019 Mar 01 PG - 2456 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2456K AB - Bi-lobate form is / Hard to visualize but / When in doubt, use clay.

PT - Conference TI - Potential Mapping Schemes and Reference Systems for MU69 AU - Beyer, R. A. AU - Weaver, H. A. AU - Porter, S. B. AU - Grundy, W. M. AU - Moore, J. M. AU - Beddingfield, C. B. AU - Lauer, T. R. AU - Olkin, C. B. AU - Parker, J. W. AU - Robbins, S. J. AU - Schenk, P. S. AU - Showalter, M. R. AU - Spencer, J. R. AU - Stern, S. A. AU - Verbiscer, A. J. AU - Zangari, A. M. AU - New Horizons Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2258 DP - 2019 Mar 01 PG - 2258 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2258B AB - These are the New Horizons Team's initial thoughts about how to apply mapping schemes and cartographic reference systems to the bi-lobate contact binary MU69.

PT - Conference TI - Impact Craters on 2014 MU69: Implications for the Geologic History of MU69 and Kuiper Belt Population Size-Frequency Distributions AU - Singer, K. N. AU - McKinnon, W. B. AU - Spencer, J. R. AU - Weaver, H. A. AU - Lauer, T. R. AU - Moore, J. M. AU - Greenstreet, S. AU - Gladman, B. AU - Kavelaars, J. J. AU - Schenk, P. M. AU - Bray, V. J. AU - Robbins, S. J. AU - White, O. L. AU - Stern, S. A. AU - Lisse, C. M. AU - Dhingra, R. D. AU - Britt, D. T. AU - Beyer, R. A. AU - Umurhan, O. M. AU - Grundy, W. M. AU - Young, L. A. AU - Olkin, C. B. AU - Parker, J. W. AU - Verbiscer, A. J. AU - New Horizons Geology AU - Geophysics Team AU - New Horizons Ralph Team AU - Lorri Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2239 DP - 2019 Mar 01 PG - 2239 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2239S AB - The craters on 2014 MU69, or the lack thereof, will provide information on the evolution of the body itself and the size-distribution of Kuiper belt objects.

PT - Conference TI - The Geology of 2014 MU69 ("Ultima Thule"): Initial Results from The New Horizons Encounter AU - Moore, J. M. AU - McKinnon, W. B. AU - Spencer, J. R. AU - Stern, S. A. AU - Binzel, R. P. AU - Britt, D. AU - Buie, M. W. AU - Buratti, B. J. AU - Cheng, A. F. AU - Grundy, W. M. AU - Kavelaars, J. J. AU - Linscott, I. R. AU - Porter, S. B. AU - Reitsema, H. J. AU - Schenk, P. M. AU - Showalter, M. R. AU - Singer, K. N. AU - Young, L. A. AU - Zangari, A. M. AU - Weaver, H. A. AU - Olkin, C. B. AU - Parker, J. W. AU - Verbiscer, A. J. AU - Beddingfield, C. AU - Beyer, R. A. AU - Bierson, C. J. AU - Bray, V. J. AU - Chaikin, A. AU - Chavez, C. L. AU - Dhingra, R. D. AU - El-Maarry, M. R. AU - Keane, J. T. AU - Hamilton, D. P. AU - Hofgartner, J. D. AU - Kinczyk, M. AU - Lauer, T. R. AU - Lisse, C. M. AU - Nimmo, F. AU - Robbins, S. J. AU - Runyon, K. D. AU - Stryk, T. AU - Throop, H. AU - Umurhan, O. M. AU - White, O. L. AU - New Horizons Science Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2152 DP - 2019 Mar 01 PG - 2152 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2152M AB - Overview of very preliminary limited-data geological analysis of MU69, with the promise that many new, quite substantial results will be presented at the talk.

PT - Conference TI - Chaos Terrains on Pluto, Europa, and Mars - Morphological Comparison of Blocks AU - Skjetne, H. L. AU - Singer, K. N. AU - Hynek, B. M. AU - Knight, K. I. AU - Olkin, C. B. AU - Bertrand, T. AU - Schenk, P. M. AU - McKinnon, W. B. AU - White, O. L. AU - Grundy, W. M. AU - Moore, J. M. AU - Stern, S. A. AU - Runyon, K. D. AU - Weaver, H. A. AU - Young, L. A. TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2146 DP - 2019 Mar 01 PG - 2146 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2146S AB - The size and height distribution of chaotic terrain blocks could provide information about the formation of chaos, and the lithologic structure of the crust.

PT - Conference TI - Potential Implications of the Shape of 2014 MU69 for Interpreting Other KBO Lightcurves AU - Showalter, M. R. AU - Buie, M. W. AU - Grundy, W. M. AU - Hamilton, D. P. AU - Kaufmann, D. E. AU - Lauer, T. R. AU - Mehoke, D. S. AU - Mehoke, T. S. AU - Porter, S. B. AU - Spencer, J. R. AU - Throop, H. B. AU - Verbiscer, A. J. AU - Zangari, A. M. AU - Weaver, H. A. AU - Olkin, C. B. AU - Parker, J. W. AU - Stern, S. A. AU - New Horizons Geology AU - Geophysics Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2132 DP - 2019 Mar 01 PG - 2132 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2132S AB - The hypothesis that many KBOs are contact binaries (similar in shape to 2014 MU69) has testable implications for the distribution of KBO lightcurves.

PT - Conference TI - The Colors of 486958 2014 MU69 ("Ultima Thule"): The Role of Synthetic Organic Solids (Tholins) AU - Cruikshank, D. P. AU - Grundy, W. M. AU - Britt, D. T. AU - Quirico, E. AU - Schmitt, B. AU - Scipioni, S. AU - Dalle Ore, C. M. AU - Cook, J. C. AU - Gabasova, L. AU - Protopapa, S. AU - Stern, S. A. AU - Weaver, H. A. AU - Verbiscer, A. J. AU - Spencer, J. R. AU - New Horizons Composition Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2051 DP - 2019 Mar 01 PG - 2051 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2051C AB - The red-orange color of 2014 MU69 is strongly suggestive of the presence of refractory organic complexes synthesized in the laboratory (tholins).

PT - Conference TI - Colors of (486958) 2014 MU69 as Observed by New Horizons' Multi-Spectral Visible Imaging Camera (MVIC) AU - Howett, C. J. A. AU - Parker, A. H. AU - Olkin, C. B. AU - Protopapa, S. AU - Grundy, W. AU - Schmitt, B. AU - Kavelaars, J. AU - Britt, D. AU - Parker, J. W. AU - Reuter, D. AU - Stern, S. A. AU - Spencer, J. R. AU - Verbiscer, A. J. AU - Weaver, H. A. TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.1982 DP - 2019 Mar 01 PG - 1982 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.1982H AB - First results of 486958 MU69 are presented; it is shown to be red and bi-lobed. The two lobes have a consistent color, while the neck region is less red.

PT - Conference TI - Overview of Initial Results from the Reconnaissance Flyby of a Kuiper Belt Planetesimal: 2014 MU69 AU - Stern, S. A. AU - Spencer, J. R. AU - Weaver, H. A. AU - Olkin, C. B. AU - Moore, J. M. AU - Grundy, W. M. AU - Gladstone, G. R. AU - McKinnon, W. B. AU - Cruikshank, D. P. AU - Young, L. A. AU - Elliott, H. A. AU - Verbiscer, A. J. AU - Parker, J. W. AU - New Horizons Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.1742 DP - 2019 Mar 01 PG - 1742 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.1742S AB - On 1 Jan 2019, NASA's New Horizons mission conducted a close flyby of KBO 2014 MU69 nicknamed Ultima Thule. Here we summarize the earliest results of that flyby.

PT - Conference TI - Characterization of Possible Two Liquid Layers in Titan Seas AU - Hanley, J. AU - Groven, J. J. AU - Grundy, W. M. AU - Dustrud, S. AU - Engle, A. E. AU - Lindberg, G. E. AU - Tegler, S. C. TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.1712 DP - 2019 Mar 01 PG - 1712 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.1712H AB - Two liquid layers / Exist at depth in the seas / Of the moon Titan.

PT - Conference TI - A Contact Binary in the Kuiper Belt: The Shape and Pole of (486958) 2014 MU69 AU - Porter, S. B. AU - Bierson, C. J. AU - Umurhan, O. AU - Beyer, R. A. AU - Lauer, T. A. AU - Buie, M. W. AU - Parker, A. H. AU - Kinczyk, M. AU - Runyon, K. AU - Grundy, W. M. AU - Kavelaars, J. J. AU - Zangari, A. M. AU - El-Maarry, M. R. AU - Britt, D. T. AU - Moore, J. M. AU - Verbiscer, A. J. AU - Parker, J. W. AU - Olkin, C. B. AU - Weaver, H. A. AU - Spencer, J. R. AU - Stern, S. A. AU - New Horizons GGI Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.1611 DP - 2019 Mar 01 PG - 1611 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.1611P AB - Two siblings hold hands / Spinning together in the void / Now visited.

PT - Conference TI - Distribution and Energy Balance of Pluto's Nitrogen Ice, as seen by New Horizons in 2015 AU - Lewis, Briley L. AU - Stansberry, John AU - Holler, Bryan AU - Grundy, William AU - Schmitt, Bernard AU - Protopapa, Silvia AU - Stern, S. Alan AU - Young, Leslie AU - Weaver, Harold AU - Olkin, Catherine AU - Ennico, Kimberly TA - American Astronomical Society Meeting Abstracts #233 SO - American Astronomical Society, AAS Meeting #233, id.255.12 VI - 233 DP - 2019 Jan 01 PG - 255.12 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23325512L AB - Pluto's surface is geologically complex, to a significant extent because of volatile ice frosts that are mobile on seasonal and longer time scales. Here, we analyze New Horizons LEISA spectral data to globally map the nitrogen ice, including nitrogen with methane diluted in it, in order to learn about the seasonal processes influencing ice redistribution, and to calculate the globally averaged energy balance. We take advantage of the shifted bands of methane in solid solution with nitrogen, which are much stronger than the 2.15-micron nitrogen band, to more completely map the distribution of the nitrogen ice. We present the resulting maps of the encounter-hemisphere distribution of nitrogen, as well as characterization of its average latitudinal dependence and an examination of how the distribution at the global scale depends on topography. We also use the encounter-hemisphere distribution of nitrogen ice to infer the latitudinal distribution of nitrogen over the rest of Pluto, allowing us to calculate the global energy balance. Under the assumption that Pluto's nitrogen-dominated 11.5 microbar atmosphere is in vapor-pressure equilibrium with the nitrogen ice, the ice temperature is 37.18±0.10 K. Combined with our global energy balance calculation, this implies that the average bolometric emissivity of Pluto's nitrogen ice is probably in the range 0.5 - 0.9, and that there is a significant reservoir of N2 ice in the un-illuminated areas south of -38° latitude. The global pattern of volatile transport at the time of the encounter was from north to south, with condensation of volatile ices likely occurring southward from approximately Pluto's equator (including in the un-illuminated regions south of -38° latitude). The transition between condensation and sublimation within Sputnik Planitia is correlated with changes in the grain size and CH4 concentration derived from the spectral maps. The low emissivity of Pluto's N2 ice suggests that Pluto's atmosphere may undergo an extended period of constant pressure even as Pluto recedes from the Sun in its orbit.

PT - Conference TI - Research scientists in support of facilities and missions: Facility support and research as an interlocked pair AU - Soderblom, David AU - Wilkes, Belinda AU - Saha, Abhijit AU - Hall, Jeff AU - Chené, André-Nicolas AU - Pevtsov, Alexei AU - Peterson, Bradley M. TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, APC white papers, no. 116; Bulletin of the American Astronomical Society, Vol. 51, Issue 7, id. 116 (2019) VI - 51 DP - 2019 Sep 01 PG - 116 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51g.116S AB - Scientists who themselves depend on the facilities that they support have a much deeper knowledge of the facilities, leading to better user support, new modes, more efficient telescope use, and overall more and better scientific output. This white paper supports the value of research scientists at facilities and missions.

PT - Conference TI - Light Pollution, Radio Interference, and Space Debris: Threats and Opportunities in the 2020s AU - Hall, Jeffrey AU - Allen, Lori AU - Arion, Douglas AU - Barentine, John AU - Caton, Daniel AU - Liszt, Harvey AU - Lowenthal, James AU - McKenna, Dan AU - Pipkin, Ashley AU - Seitzer, Patrick AU - Walker, Constance TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, APC white papers, no. 97; Bulletin of the American Astronomical Society, Vol. 51, Issue 7, id. 97 (2019) VI - 51 DP - 2019 Sep 01 PG - 97 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51g..97H AB - In this white paper, we will outline threats to astronomy in the areas of light pollution, radio interference, and space debris, and we will specify key principles and policy points that the AAS and other advocates can use in mitigating these threats.

PT - Conference TI - Strategies for Detecting Chlorine Salts in Visible/Near-Infrared Spectra at Mars AU - Carmack, R. AU - Hanley, J. AU - Horgan, B. TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.1701 DP - 2019 Mar 01 PG - 1701 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.1701C AB - We developed two new parameters and a rubric for identification of oxychlorine salts in visible/near-infrared spectra at Mars.

PT - Journal Article TI - The Nature of Low-Density Star Formation AU - Thilker, David AU - Lee, Janice AU - Capak, Peter AU - Cook, David AU - Dale, Danny AU - Elmegreen, Bruce AU - Gil de Paz, Armando AU - Gallagher, Jay AU - Hunter, Deidre AU - Leroy, Adam AU - Meurer, Gerhardt AU - Pisano, D. J. AU - Rafelski, Marc AU - Tosi, Monica AU - Wofford, Aida TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, science white papers, no. 525; Bulletin of the American Astronomical Society, Vol. 51, Issue 3, id. 525 (2019) VI - 51 DP - 2019 May 01 PG - 525 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51c.525T AB - How do stars manage to form within low-density, HI-dominated gas? Here we outline fundamental questions about the nature of star formation at low- density. We describe the wide-field, high-resolution imaging of stars, star clusters, and gas clouds in nearby galaxies needed to provide definitive answers and build a complete theory of star formation.

PT - Conference TI - Enabling Efficient HST UV Exploration of the Low Surface Brightness Universe AU - Thilker, David AU - Lee, Janice AU - Rafelski, Marc AU - Sunnquist, Ben AU - Boissier, Samuel AU - Cignoni, Michele AU - Elmegreen, Bruce G. AU - Elmegreen, Debra AU - Gil de Paz, Armando AU - Hunter, Deidre AU - Krumholz, Mark AU - MacKenty, John AU - Meurer, Gerhardt AU - Teplitz, Harry I. AU - Tosi, Monica AU - Wofford, Aida TA - American Astronomical Society Meeting Abstracts #233 SO - American Astronomical Society, AAS Meeting #233, id.443.10 VI - 233 DP - 2019 Jan 01 PG - 443.10 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23344310T AB - We present a pilot program with HST to broadly enable high-resolution UV exploration of star formation at low densities in nearby galaxies using a strategy to increase observing efficiency by up to a factor of two. The increased efficiency achieved with WFC3's eXtra-wide filter set makes more tractable programs which require several tens to hundreds of orbits to aggregate sufficient numbers of resolved massive stars, young star clusters, and clumps to build statistical samples. We aim to enable basic characterization of the ensemble properties of star formation in the low density regime in its primary units. We will discuss first results based on a Local Volume dwarf galaxy (Holmberg I) and a more distant low surface brightness spiral (UGC 9024).

PT - Conference TI - Mechanisms for Inducing Star Formation in the Dwarf Irregular Galaxy DDO 133 AU - Laufman, Lauren AU - Hunter, Deidre AU - Oh, Se-Heon TA - American Astronomical Society Meeting Abstracts #233 SO - American Astronomical Society, AAS Meeting #233, id.351.18 VI - 233 DP - 2019 Jan 01 PG - 351.18 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23335118L AB - Dwarf irregular galaxies are important to study for several reasons. First, they are the most abundant galaxy in the universe; in the Local Group we have more than fifty dwarfs and just three spirals. In addition to being the most common, they are the closest analogue to the building blocks of the early universe and their lack of heavy elements imitates early universe star formation conditions. However, the models say that dwarf irregulars shouldn't be able to continuously form stars; they aren't dense enough to reach the critical density for gravitational instabilities to form and collapse the gas clouds. We present a study of peculiar gas motions and their connection with star formation in the dwarf irregular galaxy DDO 133. Using primarily HI data cubes from the VLA, we build moment maps to identify the motion and location of the gas, and use previously written code to deconvolve these moment maps into bulk and peculiar motions. We identify a stellar bar in DDO 133 with characteristic streaming motions of HI around said bar, likely causing the significant amounts of HI and star formation observed at the ends of the bar. This research was funded by NSF grant 1461200 to Northern Arizona University to support the 2018 Research Experiences for Undergraduates program.

PT - Conference TI - Results from a stellar occultation by KBO Varda AU - Schindler, K. AU - Bosh, A. S. AU - Levine, S. E. AU - Person, M. J. AU - Wolf, J. AU - Zuluaga, C. AU - Krabbe, A. TA - AGU Fall Meeting Abstracts SO - American Geophysical Union, Fall Meeting 2019, abstract #P42C-08 VI - 2019 DP - 2019 Dec 01 PG - P42C-08 4099- https://ui.adsabs.harvard.edu/abs/2019AGUFM.P42C..08S AB - We present results obtained from a stellar occultation by the classical Kuiper belt object (174567) Varda on 10 September 2018. Varda is a known binary system and among the largest TNOs known today, but has not been studied during an occultation before. Among our collaborators, 24 stations were able to acquire data at the time of the event, of which 15 obtained a clear detection, making this the best-sampled occultation of a TNO to date. As potential stellar duplicity could cause a significant shift of the ground path, we studied the target star in advance through speckle imaging with 'Alopeke at Gemini North. The reconstructed shape is an ellipsoid, which supports Varda's status as a dwarf planet candidate. Albeit slightly smaller, the calculated size is in agreement with the radiometric diameter based on Herschel/PACS FIR measurements. Post-event analysis of the dataset obtained at DCT revealed a faint, unresolved companion or background star very close to the target, which was well under the detection limit of our speckle imager data, but had practically no effect on the predicted path. No atmosphere has been detected. The occultation helped to constrain size and albedo, which in turn helps to better constrain Varda's density.

PT - Conference TI - Stellar Occultations by Pluto: 2017-2018 AU - Sickafoose, A. A. AU - Bosh, A. S. AU - Levine, S. E. AU - Person, M. J. AU - Schindler, K. AU - Zuluaga, C. A. TA - Pluto System After New Horizons SO - Pluto System After New Horizons, held 14-18 July, 2019 in Laurel, Maryland. LPI Contribution No. 2133, 2019, id.7026 VI - 2133 DP - 2019 Jul 01 PG - 7026 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2133.7026S AB - Pluto's evolving atmosphere has been studied by stellar occultations since the 1980s. New Horizons provided in situ measurements in 2015. We present results from five occultations by Pluto in 2017/ 2018, which continue the atmospheric monitoring.

PT - Conference TI - Finding the Youngest Exoplanets AU - Prato, Lisa AU - Johns-Krull, Christopher AU - Llama, Joe AU - Jaffe, Daniel AU - Nofi, Larissa AU - Flagg, Laura AU - Clarke, Cathie AU - Hartigan, Patrick AU - Biddle, Lauren AU - Skiff, Brian AU - Mace, Gregory AU - Carvalho, Adolfo TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-1078 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-1078 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13.1078P AB - In spite of the diverse wealth of data provided by the identification of thousands of planets spanning a broad parameter space, we know little about young (less than a few Myr old) planets. To advance our understanding of the processes governing planet formation and evolution, we need to find and characterize young planets themselves. Given the extreme activity inherent in young stars, particularly those with active, primordial accretion disks, this is a challenging undertaking. We describe our search for young exoplanets and recent results.

PT - Conference TI - Asteroid Photometry from the Transiting Exoplanet Survey Satellite AU - McNeill, Andrew AU - Mommert, Michael AU - Trilling, David AU - Chandler, Colin AU - Llama, Joe TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-318 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-318 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..318M AB - We present photometric measurements for main belt asteroids (MBAs) measured by the Transiting Exoplanet Survey Satellite (TESS). TESS data provides a unique opportunity to measure the how the brightness of thousands of asteroids change continuously for twenty-seven days and is the first data set to allow a probe of long asteroid rotation periods. We present a sample of the 300 constrained rotation periods and 6600 partial light curves obtained from Sectors 1+2 of the TESS Public Data Release, allowing us to learn about the shapes and rotational properties of these objects. We aim to continue this project through the mission lifetime of TESS and expect to obtain 4000 rotation periods and partial data for a further 48000 asteroids.

PT - Conference TI - Support the Python Numerical Core AU - Harrington, Joseph AU - Gommers, Ralf AU - Gentemann, Chelle AU - Buzasi, Derek AU - Stevenson, Kevin AU - Pepper, Joshua AU - Greenfield, Perry AU - Kanodia, Shubham AU - Beatty, Thomas AU - Challener, Ryan AU - Ninan, Joe AU - Christiansen, Jessie AU - Solmaz, Arif AU - Tollerud, Erik AU - Earl, Nicholas AU - Lim, Pey Lian AU - Bradley, Larry AU - Newton, Elisabeth AU - Akeson, Rachel AU - Sosey, Megan AU - Hodge, Philip AU - Miles-Páez, Paulo AU - Labrie, Kathleen AU - Ngo, Henry AU - Ogaz, Sara AU - Williams, Darren AU - Himes, Michael AU - McIntyre, Kathleen AU - Dove, Adrienne AU - Colwell, Joshua AU - Llama, Joe AU - Hamilton, Ryan T. AU - Barentsen, Geert AU - Terrien, Ryan TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, APC white papers, no. 265; Bulletin of the American Astronomical Society, Vol. 51, Issue 7, id. 265 (2019) VI - 51 DP - 2019 Sep 01 PG - 265 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51g.265H AB - Open-source software (OSS) promotes reproducibility and efficiency in science. The most popular OSS framework in astrophysics is the Python Numerical Core (PNC), including the NumPy, SciPy, Matplotlib, Pandas, and Scikit-learn packages. With over 5,000,000 users, these projects have grown beyond the volunteer scale and require financial support.

PT - Conference TI - The Navy Precision Optical Interferometer AU - van Belle, Gerard AU - Armstrong, J. Thomas AU - Baines, Ellyn AU - Llama, Joe AU - Schmitt, Henrique TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, APC white papers, no. 104; Bulletin of the American Astronomical Society, Vol. 51, Issue 7, id. 104 (2019) VI - 51 DP - 2019 Sep 01 PG - 104 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51g.104V AB - We outline a plan for NPOI for 2020-2030 that will provide the highest resolution visible-light system on the planet, with multi-km baselines and sub-mas imaging. This capability will resolve the sizes and shapes of stars, resolve AGNs, image protoplanetary disks, and observe the passage of exoplanets across their stellar disks.

PT - Conference TI - Formation and atmospheric constraints of the youngest hot Jupiter. AU - Llama, Joe AU - Johns-Krull, Christopher AU - Prato, Lisa AU - Nofi, Larissa AU - Jaffe, Daniel AU - Biddle, Lauren AU - Flagg, Laura AU - Mace, Gregory TA - AAS/Division for Extreme Solar Systems Abstracts SO - American Astronomical Society, Extreme Solar Systems 4, id. 322.02. Bulletin of the American Astronomical Society, Vol. 51, No. 6 VI - 51 DP - 2019 Aug 01 PG - 322.02 4099- https://ui.adsabs.harvard.edu/abs/2019ESS.....432202L AB - The last three years have ushered in the era of young exoplanets. Despite young stars exhibiting extreme levels of variability, a handful of newly formed exoplanets have been detected through transits and radial velocity. We will present the latest results from our young planet survey. For the first time, using high-resolution infrared spectra, we have a direct detection of CO in the atmosphere of the youngest exoplanet CI Tau b, confirming the planet, and providing evidence for a hot start mechanism. Our discovery shows that hot Jupiters either form incredibly close to their parent star, or, that migration occurs within the first 2 Myr.

PT - Conference TI - Magnetic fields of hot Jupiters calculated from star-planet interactions AU - Cauley, Paul Wilson AU - Shkolnik, Evgenya L. AU - Llama, Joe AU - Lanza, Antonino TA - AAS/Division for Extreme Solar Systems Abstracts SO - American Astronomical Society, Extreme Solar Systems 4, id. 319.09. Bulletin of the American Astronomical Society, Vol. 51, No. 6 VI - 51 DP - 2019 Aug 01 PG - 319.09 4099- https://ui.adsabs.harvard.edu/abs/2019ESS.....431909C AB - Planetary magnetic fields have a critical impact on atmospheric physics, damping winds on hot, short-period planets and potentially creating the necessary conditions for habitability on temperate terrestrial worlds by deflecting stellar wind particles. Despite their importance, exoplanet magnetic field detections remain elusive. For the first time, we report the derivation of the magnetic fields of a sample of hot Jupiters using flux-calibrated signals of magnetic star-planet interactions (SPI). We find that the surface magnetic field values for the hot Jupiters in our sample range from 20 G to 120 G, 10 - 50 times larger than the values predicted by pure dynamo theories for planets with rotation periods of 2 to 4 days. Such large field strengths should have severe consequences for velocity flows in the planets' atmospheres and exhibit peak frequencies of electron-cyclotron emission in the range of facilities such as LOFAR.

PT - Conference TI - Direct Detection of CO in CI Tau b: Support for Hot Start Formation AU - Johns-Krull, Christopher M. AU - Flagg, Laura AU - Nofi, Larissa AU - Llama, Joe AU - Prato, Lisa A. AU - Sullivan, Kendall AU - Jaffe, Daniel Thomas AU - Mace, Gregory N. TA - American Astronomical Society Meeting Abstracts #234 SO - American Astronomical Society Meeting #234, ids. 105.04, 221.04. VI - 234 DP - 2019 Jun 01 PG - s 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23410504J AB - We analyze high resolution IR spectra of CI Tau, the host star of one of the few young planet candidates amenable to such observations. We confirm the planet's existence with a direct detection of CO in the planet's atmosphere. We determine a mass of 11.6 Mjup based on the amplitude of the planet's radial velocity variations. We estimate the planet's flux contrast with its host star to obtain an absolute magnitude estimate for the planet of 8.17 in the K band. This magnitude implies the planet formed via a "hot start" formation mechanism. This makes CI Tau b the youngest confirmed exoplanet as well as the first exoplanet around a T Tauri star with a directly determined, model- independent, dynamical mass.

PT - Journal Article TI - Constraining Stellar Photospheres as an Essential Step for Transmission Spectroscopy of Small Exoplanets AU - Rackham, Benjamin AU - Pinhas, Arazi AU - Apai, Dániel AU - Haywood, Raphaëlle AU - Cegla, Heather AU - Espinoza, Néstor AU - Teske, Johanna AU - Gully-Santiago, Michael AU - Rau, Gioia AU - Morris, Brett M. AU - Angerhausen, Daniel AU - Barclay, Thomas AU - Carone, Ludmila AU - Cauley, P. Wilson AU - de Wit, Julien AU - Domagal-Goldman, Shawn AU - Dong, Chuanfei AU - Dragomir, Diana AU - Giampapa, Mark S. AU - Hasegawa, Yasuhiro AU - Hinkel, Natalie R. AU - Hu, Renyu AU - Jordán, Andrés AU - Kitiashvili, Irina AU - Kreidberg, Laura AU - Lisse, Carey AU - Llama, Joe AU - López-Morales, Mercedes AU - Mennesson, Bertrand AU - Molaverdikhani, Karan AU - Osip, David J. AU - Quintana, Elisa V. TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, science white papers, no. 328; Bulletin of the American Astronomical Society, Vol. 51, Issue 3, id. 328 (2019) VI - 51 DP - 2019 May 01 PG - 328 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51c.328R AB - Transmission spectra probe the atmospheres of transiting exoplanets, but these observations are also subject to signals introduced by magnetic active regions on host stars. We outline scientific opportunities in the next decade for providing useful constraints on stellar photospheres for the purposes of exoplanet transmission spectroscopy.

PT - Conference TI - Detection of water in the atmosphere of the hot Jupiter HD 102195b AU - Llama, Joe AU - Cabrera, Tomas AU - Luna, Jessica AU - Birkby, Jayne AU - Brogi, Matteo AU - Nofi, Larissa TA - American Astronomical Society Meeting Abstracts #233 SO - American Astronomical Society, AAS Meeting #233, id.247.32 VI - 233 DP - 2019 Jan 01 PG - 247.32 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23324732L AB - The composition and structure of hot Jupiter atmospheres provide a fossil record of their primordial origins, potentially holding the key to distinguishing between the various proposed formation mechanisms. High-resolution spectroscopic observations of exoplanet atmospheres enable us to resolve molecular bands into many individual spectral lines in a pattern that is unique to each molecule. By then exploiting the Doppler shift of the planet over multiple nights we can separate the planet spectrum from that of the host star and Earths atmosphere. Here, we use the high-resolution infrared spectrograph IGRINS (R=45,000, λ=1.4-2.5 microns) on the 4.3m Discovery Channel Telescope to observe the spectrum of the hot Jupiter HD 102195b. Our analysis reveals a 4σ detection of water in the atmosphere of this heavily irradiated hot Jupiter.

PT - Conference TI - Preliminary Results from a Young Exoplanet RV Survey AU - Nofi, Larissa AU - Prato, Lisa AU - Johns-Krull, Christopher AU - Llama, Joe AU - Sullivan, Kendall AU - Skiff, Brian AU - Biddle, Lauren TA - American Astronomical Society Meeting Abstracts #233 SO - American Astronomical Society, AAS Meeting #233, id.140.25 VI - 233 DP - 2019 Jan 01 PG - 140.25 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23314025N AB - Observing and characterizing newly-formed planets around young stars is important for developing planet formation and evolution theory. However, given challenges in detecting young planetary systems, current models are primarily based on systems that are billions of years old. It is therefore unclear which exoplanetary properties are indicators of formation conditions, or of later evolution. We are conducting an infrared radial velocity survey to detect and confirm young exoplanets around T Tauri stars using the Immersion Grating Infrared Spectrograph (IGRINS) on the 4.3-m Lowell Observatory Discovery Channel Telescope (DCT). IGRINS simultaneously observes H- and K-bands at a resolution of ~45,000. Infrared spectroscopy is less susceptible to apparent RV variability caused by starspots on active young stars than optical observations. Our sample consists of ~100 T Tauri stars of age 1 to a few Myr in the relatively nearby Taurus star forming region. We present early results on our search for RV variability of T Tauri stars, indicative of the presence of hot Jupiters with the IGRINS + DCT system.

PT - Conference TI - Shedding Light on the Isolation of Luminous Blue Variables AU - Aadland, Erin AU - Massey, Philip AU - Neugent, Kathryn AU - Drout, Maria TA - American Astronomical Society Meeting Abstracts #233 SO - American Astronomical Society, AAS Meeting #233, id.353.05 VI - 233 DP - 2019 Jan 01 PG - 353.05 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23335305A AB - In the traditional view of massive star evolution, luminous blue variables (LBVs) are a transitionary phase between massive O-type stars and Wolf-Rayet stars (WRs). A debate has sprouted over whether this single star evolution is flawed and perhaps a binary evolutionary track describes the LBV phase better. The root of this debate has been the question of isolation (projected angular separation) of LBVs from their nearest neighboring O-type star. LBVs, traditionally, have relatively short lifetimes, and as a result they should not disperse far from their birthplace or be isolated. A recent study found that LBVs have an isolation more similar to that of red supergiants (RSGs) than traditionally thought possible given single star evolution. A similar study, however, found the opposite result. Both of these studies used spectroscopically identified O-type stars, which for the Large Magellanic Cloud is extremely incomplete, and does not necessarily represent the high mass stars we expect to be LBV progenitors in any event. Therefore, we re-examined the question of isolation using photometric criteria to select the highest mass unevolved stars ("bright blue stars" or BBSs) to use as our comparison sample. We find that LBVs are no more isolated than BBSs or WRs, and were able to statistically rule out the possibility of LBVs coming from the same distribution as the RSGs. We also note the number of LBVs in or near OB associations is comparable to the number of BBSs or WRs, and not to that of RSGs. Therefore, we conclude that the isolation of LBVs is consistent with the traditional picture of massive single star evolution. This work was supported by the National Science Foundation through AST-1612874.

PT - Conference TI - A Modern Search for Wolf-Rayet (WR) Stars in the Magellanic Clouds: A Final Census AU - Massey, Philip AU - Neugent, Kathryn AU - Morrell, Nidia AU - Hillier, Desmond J. TA - American Astronomical Society Meeting Abstracts #233 SO - American Astronomical Society, AAS Meeting #233, id.353.01 VI - 233 DP - 2019 Jan 01 PG - 353.01 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23335301M AB - Wolf-Rayet (WR) stars evolved from massive OB stars, where the outer hydrogen-rich layers have been stripped away by some mechanism: stellar winds, close binary companions, episodic mass-loss during a Luminous Blue Variable phase, or all of the above. We have recently carried out a new survey of the Small and Large Magellanic Clouds (SMC, LMC) discovering 15 new WR in the LMC, bringing the total known to 154. We also found 12 Of-type stars, incluing rare Onfp and Of?p stars, and a variety of other interesting emission-lined stars. Most exciting, however, has been our discovery of new class of WRs, which we are calling WN3/O3s. These have the typical emission lines of a high- excitation nitrogen-rich (WN) Wolf-Rayet, but the absorption lines of a hot O-type star. However, they are many magnitudes too faint to be WN3+O3 binaries. Rather, the emission and absorption originate from the same object. Detailed analysis of our Magellan spectra have shown that the physical properties of these stars are similar to normal WNs, but with the presence of more hydrogen and much lower mass-loss rates. About 8% of the LMC's WN-type population is made up of these newly found objects, and so these are not a consequence of some rare and special process. The question then is how did these WN3/O3s evolve? Are they simply a short-lived phase in the normal evolution of WRs, a "missing link" between O-type stars and WRs that occurs only in certain metallicity regimes? Or have they evolved by binary evolution? Drop by our poster and hear what we have to say on the issue! This work was supported by the National Science Foundation through AST-1612874.

PT - Conference TI - Binary Red Supergiants: A New Method for Detecting B-type Companions AU - Neugent, Kathryn AU - Levesque, Emily AU - Massey, Phil TA - American Astronomical Society Meeting Abstracts #233 SO - American Astronomical Society, AAS Meeting #233, id.259.19 VI - 233 DP - 2019 Jan 01 PG - 259.19 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23325919N AB - With the exception of a few well-known and studied systems, the binary population of red supergiants (RSGs) remains relatively uncharacterized. Famous systems such as VV Cep, 31 Cyg and zeta Aur contain RSG + B star binaries and here we explore whether B stars are the main type of companion we expect from an evolutionary point of view. Using the Geneva evolutionary models we find that this is indeed the case. However, few such systems are known, and we use model spectra to determine how easy such binaries would be to detect observationally. We find that it should be quite difficult to hide a B-type companion given a reasonable signal- to-noise in the optical / blue portion of the spectrum. We next examine spectra of Magellanic Cloud RSGs and newly acquired spectra of Galactic RSGs looking for new systems and refining our conclusions about what types of stars could be hidden in the spectra. We finally develop a set of photometric criteria that can help select likely binaries in the future without the overhead of large periodic or spectroscopic surveys. We also recently observed spectra of a sample of candidate RSG+B star binaries in M31 and M33, confirming that our photometric criteria can indeed be used to select RSG+B star binaries.

PT - Conference TI - The Near-Infrared High Throughput Spectrograph AU - Gustafsson, Annika AU - Moskovitz, Nicholas AU - Roe, Henry AU - Cushing, Michael C. AU - Bida, Thomas A. TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-1190 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-1190 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13.1190G AB - NIHTS is a low resolution near-infrared spectrograph on the Discovery Channel Telescope in Happy Jack, AZ, USA. NIHTS has been fully operational since March of 2018. The instrument will enable many science use cases, including investigations into water-ice in Kuiper Belt Objects and comets, and classification of Near-Earth asteroids and ultracool brown dwarfs.

PT - Conference TI - Water-Ice Distribution in the Coma of 46P/Wirtanen AU - Gustafsson, Annika AU - Moskovitz, Nicholas AU - Protopapa, Silvia AU - Schleicher, David G. TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-1179 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-1179 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13.1179G AB - Comet 46P/Wirtanen made a close approach to the Earth in December 2018 (geocentric distance=0.077 au ; heliocentric distance=1.056 au), providing a unique opportunity to collect spatially resolved spectral observations. We created a near-infrared spectral data cube near close approach to better understand the water-ice grain properties of the comet coma.

PT - Conference TI - SPECTROSCOPYPIPELINE: multi-instrument python-based pipeline for long-slit asteroid visible spectroscopy reduction AU - Devogele, Maxime AU - Moskovitz, Nicholas TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-841 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-841 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..841D AB - SPECTROSCOPYPIPELINE (SP) is a pipeline dedicated to the reduction of long-slit visible spectroscopic data. The pipeline can perform reduction of any spectroscopic data, but has been primarily developed and optimized for complete reduction of asteroid spectroscopic observation. It is a python-based open source pipeline intended to be easily portable to any long-slit spectrometer. It currently supports both Gemini North and South GMOS instruments, Lowell Observatory's 4.3m Discovery Channel Telescope DeVeny spectrograph and the SOAR 4.1m Goodman spectrograph.

PT - Conference TI - The Mission Accessible Near-Earth Objects Survey (MANOS): taxonomic distribution of sub-kilometer NEOs AU - Devogele, Maxime AU - Moskovitz, Nicholas AU - Thomas, Cristina AU - Thirouin, Audrey AU - Mommert, Michael AU - Polishook, David AU - Skiff, Brian AU - Magnuson, Mitchell AU - Gustafsson, Annika TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-694 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-694 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..694D AB - The Mission Accessible Near-Earth Objects Survey (MANOS) is a new generation of surveys aiming to observe and characterize sub-kilometer newly discovered Near-Earth Objects (NEOs). This survey began in August 2013 and has been collecting astrometry, photometry, and reflectance spectra of this under-studied category of the NEO population. We have determined the taxonomic type of 210 asteroids with a mean size around 60 meters and as small as a few meters. This is the first comprehensive dataset for spectroscopically classified NEOs smaller than 100 meters. In the MANOS dataset, we find the population of small NEOs differ in composition from the population of larger ones. We believed this variation is due to the fact that NEOs originate from different source regions in the Main Belt. Each of these source regions have a different delivery rate efficiency as a function of object size.

PT - Conference TI - A common origin for dynamically associated near-Earth asteroid pairs AU - Moskovitz, Nicholas AU - Fatka, Petr AU - Farnocchia, Davide AU - Devogèle, Maxime AU - Polishook, David AU - Thomas, Cristina AU - Mommert, Michael AU - Thirouin, Audrey AU - Matson, Robert TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-650 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-650 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..650M AB - We present analysis that supports the existence of two genetically related asteroid pairs in near-Earth space. This work suggests that these systems formed via radiative spin-up and fission, and/or dissociation of a binary asteroid. Backwards orbital integrations suggest a separation age of <10 kyr for one of these pairs, making it one of the youngest multiple asteroid systems known to date. As the NEO catalog grows with current and future discovery surveys, the known population of NEO pairs will also increase.

PT - Conference TI - Modernizing Lowell Observatory's astorb Database AU - Moskovitz, Nicholas AU - Schottland, Robert AU - Burt, Brian AU - Wasserman, Lawrence AU - Mommert, Michael AU - Bailen, Mark AU - Grimm, Simon TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-644 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-644 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..644M AB - The astorb database is an actively currated catalog of orbits for all known asteroids in the Solar System. The full catalog is downloadable from Lowell Observatory and VizieR. The data in astorb are used to support a number of observational planning tools hosted at astetoid.lowell.edu. Since 2016 we have been funded by NASA to modernize both the underlying database infrastructure and the front-end web applications. We will present an overview of the current astorb ecosystem and plans for future development.

PT - Conference TI - New Web Portal for ASTORB, Lowell Observatory's Primary Asteroid Database AU - Bailen, M. AU - Moskovitz, N. AU - Burt, B. AU - Wasserman, L. AU - Schottland, R. TA - 4th Planetary Data Workshop SO - 4th Planetary Data Workshop, held 18-20 Jue, 2019 in Flagstaff, Arizona. LPI Contribution No. 2151, id.7007 VI - 2151 DP - 2019 Jun 01 PG - 7007 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2151.7007B AB - ASTORB is a database of orbital elements and characterization information for all known asteroids in the solar system, hosted at Lowell Observatory for over 20 years. A new web portal to access and visualize the data is soon to be released.

PT - Conference TI - Spectral Analysis of Agnia Family Members AU - Harvison, B. A. AU - Thomas, C. A. AU - Moskovitz, N. A. AU - Trilling, D. E. AU - Lim, L. F. TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.2067 DP - 2019 Mar 01 PG - 2067 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.2067H AB - We calculated spectral band parameters for eight members of the Agnia family. The spectra are consistent with PAC meteorites and partial differentiation.

PT - Journal Article TI - Disk Evolution and Dissipation in the Taurus Star-forming Region AU - Simon, M. AU - Prato, L. TA - Research Notes of the American Astronomical Society SO - Research Notes of the American Astronomical Society, Volume 3, Issue 12, article id. 186 (2019). VI - 3 DP - 2019 Dec 01 PG - 186 4099- https://ui.adsabs.harvard.edu/abs/2019RNAAS...3..186S

PT - Conference TI - High-resolution Infrared Spectrograph for Exoplanet Characterization with the Keck and Thirty Meter Telescopes AU - Mawet, Dimitri AU - Fitzgerald, Michael AU - Konopacky, Quinn AU - Beichman, Charles AU - Jovanovic, Nemanja AU - Dekany, Richard AU - Hover, David AU - Chisholm, Eric AU - Ciardi, David AU - Artigau, Étienne AU - Banyal, Ravinder AU - Beatty, Thomas AU - Benneke, Björn AU - Blake, Geoffrey A. AU - Burgasser, Adam AU - Canalizo, Gabriela AU - Chen, Guo AU - Do, Tuan AU - Doppmann, Greg AU - Doyon, René AU - Dressing, Courtney AU - Fang, Min AU - Greene, Thomas AU - Hillenbrand, Lynne AU - Howard, Andrew AU - Kane, Stephen AU - Kataria, Tiffany AU - Kempton, Eliza AU - Knutson, Heather AU - Kotani, Takayuki AU - Lafrenière, David AU - Liu, Chao AU - Nishiyama, Shogo AU - Pandey, Gajendra AU - Plavchan, Peter AU - Prato, Lisa AU - Rajaguru, S. P. AU - Robertson, Paul AU - Salyk, Colette AU - Sato, Bun'ei AU - Schlawin, Everett AU - Sengupta, Sujan AU - Sivarani, Thirupathi AU - Skidmore, Warren AU - Tamura, Motohide AU - Terada, Hiroshi AU - Vasisht, Gautam AU - Wang, Ji AU - Zhang, Hui TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, APC white papers, no. 134; Bulletin of the American Astronomical Society, Vol. 51, Issue 7, id. 134 (2019) VI - 51 DP - 2019 Sep 01 PG - 134 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51g.134M AB - HISPEC (High-resolution Infrared Spectrograph for Exoplanet Characterization) is a proposed diffraction-limited spectrograph for the W.M. Keck Observatory, and a pathfinder for the MODHIS facility project (Multi-Object Diffraction-limited High-resolution Infrared Spectrograph) on the Thirty Meter Telescope.

PT - Conference TI - Key Challenges for AAS Journals in the Next Decade AU - Levesque, Emily AU - Prato, Lisa AU - Sneden, Chris AU - Barnes, Jason AU - Gelino, Dawn M. AU - Kern, Barbara AU - Szkody, Paula AU - Wyse, Rosemary F. G. AU - Young, Leslie TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, APC white papers, no. 26; Bulletin of the American Astronomical Society, Vol. 51, Issue 7, id. 26 (2019) VI - 51 DP - 2019 Sep 01 PG - 26 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51g..26L AB - The AAS Journals are a vital asset to astronomy, but the page charge model for funding their publication could prove challenging in the open access (OA) era. Discussing alternative models for funding publishing costs must be part of Astro2020. We recommend that the NAS form a task force to address the concerns highlighted in this white paper.

PT - Conference TI - Radial Velocity Monitoring of the Young Star Hubble 4 AU - Carvalho, Adolfo AU - Johns-Krull, Christopher M. AU - Prato, Lisa A. TA - American Astronomical Society Meeting Abstracts #234 SO - American Astronomical Society Meeting #234, id. 201.06. VI - 234 DP - 2019 Jun 01 PG - 201.06 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23420106C AB - We have been spectroscopically monitoring the young star Hubble 4 for approximately 10 years using the 2.7 m Harlan J. Smith telescope at McDonald Observatory. Our goal is to monitor this star's radial velocity (RV) variations, and we have collected over 65 observations of this 2-3 Myr old T Tauri star. In addition, we analyze archival imaging of Hubble 4 obtained with the ACS instrument aboard the Hubble Space Telescope to measure the flux ratio between the members of this binary system. The RV measurements of Hubble 4 clearly reveal the long period ( 9 yr) variations due to the orbit of this binary (semi-major axis of 5.6 AU) as well as much shorter period ( 1.5 d) variations due to stellar rotation. By fitting and removing the variations due to orbital motion, we also find lower bound of 5 yr on the lifetime of star spots on the surface of the star. We discuss the implications of these findings for RV searches aimed at detecting planets around young stars.

PT - Journal Article TI - Binary and Multiple Star Systems at High Angular Resolution AU - Schaefer, Gail AU - Duchene, Gaspard AU - Farrington, Christopher D. AU - Gardner, Tyler AU - Gies, Douglas R. AU - Kraus, Adam AU - Monnier, John D. AU - Prato, Lisa AU - Ridgway, Stephen AU - Roettenbacher, Rachael AU - Stencel, Robert E. AU - ten Brummelaar, Theo AU - van Belle, Gerard TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, science white papers, no. 483; Bulletin of the American Astronomical Society, Vol. 51, Issue 3, id. 483 (2019) VI - 51 DP - 2019 May 01 PG - 483 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51c.483S AB - Binary and multiple star systems provide laboratories for measuring stellar masses and studying star formation, stellar evolution, and dynamical evolution over time. This paper outlines several areas in the context of binary stars that can be advanced over the next decade.

PT - Conference TI - Binary Stars and their Planet-Forming Disks AU - Lindstrom, Kyle AU - Prato, Lisa AU - Graham, Sean AU - Johns-Krull, Christopher AU - Nofi, Larissa AU - Sullivan, Kendall TA - American Astronomical Society Meeting Abstracts #233 SO - American Astronomical Society, AAS Meeting #233, id.367.04 VI - 233 DP - 2019 Jan 01 PG - 367.04 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23336704L AB - The majority of stars in our Galaxy reside in binary or higher order multiple systems. This can have profound effects on the evolution of the stars and in particular their circumstellar disks and the planet formation therein. In this poster we address several fundamental questions: how do circumstellar disks in binaries evolve, are these disks stable, and are their properties favorable for planet formation? To address these topics, our team is completing a spectroscopic survey of over 100 binary systems in young, nearby star forming regions, including Taurus Auriga, using the Keck II and Discovery Channel Telescopes. Our goal is to analyze these spectra to infer the properties of the stars themselves, as well as their constituent disks. To accomplish this, we generate synthetic spectra with a wide range of effective temperatures, surface gravities, rotational velocities, radial velocities, veiling, and magnetic field strengths for comparison with our target spectra. We present some preliminary results and a discussion of their consequences with respect to the evolution of these systems. This research was supported in part by NSF awards AST-1313399 and AST-1518081 and by NASA Keck KPDA funds.

PT - Conference TI - Identifying and Characterizing New Spectroscopic Binaries in Orion AU - Prato, Lisa AU - Sullivan, Kendall AU - Lindstrom, Kyle AU - Graham, Sean TA - American Astronomical Society Meeting Abstracts #233 SO - American Astronomical Society, AAS Meeting #233, id.366.13 VI - 233 DP - 2019 Jan 01 PG - 366.13 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23336613P AB - Double-lined, young spectroscopic binaries provide the opportunity for precise measurements of pre-main sequence stellar mass ratios. In conjunction with additional information, such as orbital inclinations based on astrometric photocenter orbits, available in the future from GAIA, very precise stellar component masses may be determined. Mass ratio distributions yield clues to the formation of the closest binaries, a poorly understood problem. Absolute young star masses are important to test and refine the pre-main sequence evolutionary models that are central to the determination of properties such as the initial mass function, secondary star mass function, and star formation history of young clusters. We report on the results of our optical and infrared observations to identify and characterize new spectroscopic binaries in the Orion star forming region. Support for this research was provided in part by NSF award AST-1518081.

PT - Conference TI - The Lowell Observatory Predoctoral Scholar Program AU - Prato, Lisa AU - Nofi, Larissa TA - American Astronomical Society Meeting Abstracts #233 SO - American Astronomical Society, AAS Meeting #233, id.254.03 VI - 233 DP - 2019 Jan 01 PG - 254.03 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23325403P AB - Lowell Observatory is pleased to solicit applications for our Predoctoral Scholar Fellowship Program. Now beginning its eleventh year, this program is designed to provide unique research opportunities to graduate students in good standing, currently enrolled at Ph.D. granting institutions. Lowell staff research spans a wide range of topics, from astronomical instrumentation, to icy bodies in our solar system, exoplanet science, stellar populations, star formation, and dwarf galaxies. Active collaborations, the new Ph.D. program at Northern Arizona University, and strong, cooperative links across the greater Flagstaff astronomical community create an exciting, multi-institutional locus in northern Arizona. Lowell Observatory's new 4.3 meter Discovery Channel Telescope is operating at full science capacity and boasts some of the most cutting-edge and unique instrumentation available in optical/infrared astronomy. Student research is expected to lead to a thesis dissertation appropriate for graduation at the doctoral level at the student's home institution. For more information, see http://www2.lowell.edu/rsch/predoc.php and links therein. Applications for Fall 2019 are due by May 1, 2019; alternate application dates will be considered on an individual basis.

PT - Conference TI - H Band Observations of the Candidate Young Spectroscopic Binary UY Auriga B and its Disk AU - Graham, Sean AU - Prato, Lisa AU - Schaefer, Gail AU - Nofi, Larissa AU - Sullivan, Kendall AU - Wittal, Matthew M. TA - American Astronomical Society Meeting Abstracts #233 SO - American Astronomical Society, AAS Meeting #233, id.155.05 VI - 233 DP - 2019 Jan 01 PG - 155.05 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23315505G AB - Binaries dominate the stellar census; understanding disk evolution in these complex environments is crucial in order to form a complete and accurate model for planet formation. UY Auriga is a ~2 Myr old classical T Tauri binary with a separation of ~0.9". The system contains a number of complex gas-dust interactions between the circumbinary and circumstellar disks. Multiple epochs of high-resolution H-band spectroscopy show that UY Aur B exhibits extreme spectral variability over a period of 13 years or more; it is also known to be highly photometrically variable. We explore whether UY Aur B might itself be a close, short-period binary and provide estimates of accretion properties and possible orbital solutions and component mass ratios.

PT - Conference TI - Narrowband Observations of Comet 46P/Wirtanen During its Exceptional Apparition of 2018/19: Gas Jet Morphology and Rotation Period AU - Knight, Matthew AU - Farnham, Tony AU - Schleicher, David AU - Feaga, Lori AU - Bodewits, Dennis AU - Schindler, Josephine AU - Skiff, Brian TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-1035 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-1035 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13.1035K AB - An extensive observing campaign was successfully conducted for Comet 46P/Wirtanen during its excellent recent apparition of 2018/19 using several telescopes at Lowell Observatory. Narrowband imaging was obtained over a three-month interval, revealing two CN gas jets throughout the apparition. Their motion and repetition allowed us to determine a rotation period near 9 hr in early November. We continued to obtain sufficient data to constrain the rotation period through early February and detect little to no change. We see no rotational variation in dust images. C3 exhibits a similar morphology to CN, while OH shows a different spatial distribution. Analyses are ongoing and new results will be presented.

PT - Conference TI - Narrowband Observations of Comet 46P/Wirtanen During its Exceptional Apparition of 2018/19: Photometry, Jet Morphology, and Modeling Results AU - Schleicher, David AU - Knight, Mathew AU - Farnham, Tony AU - Feaga, Lori TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-740 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-740 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..740S AB - An extensive observing campaign was successfully conducted for Comet 46P/Wirtanen during its excellent recent apparition of 2018/19 using several telescopes at Lowell Observatory. Gas and dust production rates were determined throughout the apparition, while narrowband imaging was obtained over a three-month interval. Two CN gas jets were detected, and modeling of these jets is on-going.

PT - Conference TI - The search for the most ancient asteroid collisions reveals the original planetesimals of our solar system AU - Delbo, Marco AU - Walsh, Kevin AU - Avdellidou, Chrysa AU - Fornasier, Sonia AU - Deienno, Rogerio AU - Van Belle, Gerard AU - Morbidelli, Alessandro TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-877 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-877 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..877D AB - Hundred years of asteroid family research and new asteroid family identification methods have shed new light on the collisions among asteroids that shaped the main belt. In particular, in the inner portion of the belt - bracketed by the nu6 secular resonance at 2.1 au and by the J:3/1 mean motion resonance at 2.5 au - it is now possible to distinguish those asteroids that formed as collisional fragments from the break up of larger and older parents, and those other that are not fragments. This second population, which constitutes those asteroids that formed as planetsiamals by the accretion of dust in the protoplanetary disk, has a size distribution skewed towards bodies with diameters larger than 50 km. This indicates that planetesimals formed big, as previously suggested.

PT - Conference TI - A Long-Term Vision for Space-Based Interferometry AU - Rinehart, Stephen AU - Arenberg, J. AU - Baines, E. AU - Chen, C. H. AU - Cleeves, L. Ilsedore AU - Creech-Eakman, M. J. AU - Dale, D. AU - Danchi, W. AU - Farrah, D. AU - Juanola-Parramon, R. AU - Kraus, S. AU - Knight, J. S. AU - Lipscy, S. AU - Leisawitz, D. T. AU - MacGregor, M. A. AU - Mennesson, B. AU - Monnier, J. AU - Naylor, D. A. AU - O'Connor, R. AU - Roberge, A. AU - Savini, G. AU - Schmitt, H. AU - Sewilo, M. AU - Spencer, L. D. AU - ten Brummelaar, T. A. AU - van Belle, G. AU - Yorke, H. W. TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, APC white papers, no. 222; Bulletin of the American Astronomical Society, Vol. 51, Issue 7, id. 222 (2019) VI - 51 DP - 2019 Sep 01 PG - 222 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51g.222R AB - A number of important astrophysical questions require observations with angular resolution beyond the capabilities of either existing or proposed facilities. We discuss some of these key science questions and present a potential path to obtaining high angular resolution through the development of space-based interferometers.

PT - Conference TI - Revitalizing the Optical/Infrared Interferometry Community in the U.S. AU - Ridgway, Stephen AU - Armstrong, J. Thomas AU - Baines, Ellyn K. AU - van Belle, Gerard T. AU - Boyajian, Tabetha S. AU - Creech-Eakman, Michelle J. AU - ten Brummelaar, Theo A. AU - Monnier, John D. AU - Roettenbacher, Rachael M. AU - Schaefer, Gail TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, APC white papers, no. 157; Bulletin of the American Astronomical Society, Vol. 51, Issue 7, id. 157 (2019) VI - 51 DP - 2019 Sep 01 PG - 157 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51g.157R AB - Long baseline optical/infrared interferometry (LBOI) has produced groundbreaking results in stellar astrophysics and is essential for the future of high-resolution observations. We describe capabilities and recent results, discuss the development of LBOI in the U.S., and make recommendations for the support and growth of U.S. interferometry.

PT - Conference TI - A Realistic Roadmap to Formation Flying Space Interferometry AU - Monnier, John AU - Aarnio, Alicia AU - Absil, Olivier AU - Anugu, Narsireddy AU - Baines, Ellyn AU - Bayo, Amelia AU - Berger, Jean-Philippe AU - Cleeves, L. Ilsedore AU - Dale, Daniel AU - Danchi, William AU - de Wit, W. J. AU - Defrère, Denis AU - Domagal-Goldman, Shawn AU - Elvis, Martin AU - Froebrich, Dirk AU - Gai, Mario AU - Gandhi, Poshak AU - Garcia, Paulo AU - Gardner, Tyler AU - Gies, Douglas AU - Gonzalez, Jean-François AU - Gunter, Brian AU - Hoenig, Sebastian AU - Ireland, Michael AU - Jorgensen, Anders M. AU - Kishimoto, Makoto AU - Klarmann, Lucia AU - Kloppenborg, Brian AU - Kluska, Jacques AU - Knight, J. Scott AU - Kral, Quentin AU - Kraus, Stefan AU - Labadie, Lucas AU - Lawson, Peter AU - Le Bouquin, Jean-Baptiste AU - Leisawitz, David AU - Lightsey, E. Glenn AU - Linz, Hendrik AU - Lipscy, Sarah AU - MacGregor, Meredith AU - Matsuo, Hiroshi AU - Mennesson, Bertrand AU - Meyer, Michael AU - Michael, Ernest A. AU - Millour, Florentin AU - Mozurkewich, David AU - Norris, Ryan AU - Ollivier, Marc AU - Packham, Chris AU - Petrov, Romain AU - Pueyo, Laurent AU - Pope, Benjamin AU - Quanz, Sascha AU - Ragland, Sam AU - Rau, Gioia AU - Regaly, Zsolt AU - Riva, Alberto AU - Roettenbacher, Rachael AU - Savini, Giorgio AU - Setterholm, Benjamin AU - Sewilo, Marta AU - Smith, Michael AU - Spencer, Locke AU - ten Brummelaar, Theo AU - Turner, Neal AU - van Belle, Gerard AU - Weigelt, Gerd AU - Wittkowski, Markus TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, APC white papers, no. 153; Bulletin of the American Astronomical Society, Vol. 51, Issue 7, id. 153 (2019) VI - 51 DP - 2019 Sep 01 PG - 153 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51g.153M AB - The ultimate astronomical observatory would be a formation flying space interferometer, combining sensitivity and stability with high angular resolution. The smallSat revolution offers a new and maturing prototyping platform for space interferometry and we put forward a realistic plan for achieving first stellar fringes in space by 2030.

PT - Conference TI - Setting the Stage for the Planet Formation Imager AU - Monnier, John AU - Aarnio, Alicia AU - Absil, Olivier AU - Alonso-Herrero, Almudena AU - Anugu, Narsireddy AU - Baines, Ellyn AU - Bayo, Amelia AU - Berger, Jean-Philippe AU - Danchi, William AU - Elias, Nicholas AU - Gai, Mario AU - Gandhi, Poshak AU - Gardner, Tyler AU - Gies, Douglas AU - Gonzalez, Jean-François AU - Haniff, Chris AU - Hoenig, Sebastian AU - Ireland, Michael AU - Isella, Andrea AU - Kane, Stephen AU - Kirchschlager, Florian AU - Kishimoto, Makoto AU - Klarmann, Lucia AU - Kluska, Jacques AU - Kraus, Stefan AU - Labadie, Lucas AU - Le Bouquin, Jean-Baptiste AU - Leisawitz, David AU - Linz, Hendrik AU - Mennesson, Bertrand AU - Morlok, Andreas AU - Norris, Ryan AU - Pope, Benjamin AU - Quiroga-Nuñez, Luis Henry AU - Rau, Gioia AU - Regaly, Zsolt AU - Reynolds, Mark AU - Riva, Alberto AU - Roettenbacher, Rachael AU - Schaefer, Gail AU - Setterholm, Benjamin AU - Smith, Michael AU - Stencel, Robert AU - ten Brummelaar, Theo AU - Tristram, Konrad R. W. AU - van Belle, Gerard AU - Vasisht, Gautam AU - Weigelt, Gerd AU - Wittkowski, Markus TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, APC white papers, no. 133; Bulletin of the American Astronomical Society, Vol. 51, Issue 7, id. 133 (2019) VI - 51 DP - 2019 Sep 01 PG - 133 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51g.133M AB - The Planet Formation Imager (PFI) is a next-generation infrared interferometer designed to image the active phases of planet formation and to take planetary “snapshots” of young systems. We outline a technology plan to make PFI a reality, identifying a potential breakthrough opportunity for making inexpensive large telescopes available.

PT - Conference TI - The Navy Precision Optical Interferometer AU - van Belle, Gerard AU - Armstrong, J. Thomas AU - Baines, Ellyn AU - Llama, Joe AU - Schmitt, Henrique TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, APC white papers, no. 104; Bulletin of the American Astronomical Society, Vol. 51, Issue 7, id. 104 (2019) VI - 51 DP - 2019 Sep 01 PG - 104 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51g.104V AB - We outline a plan for NPOI for 2020-2030 that will provide the highest resolution visible-light system on the planet, with multi-km baselines and sub-mas imaging. This capability will resolve the sizes and shapes of stars, resolve AGNs, image protoplanetary disks, and observe the passage of exoplanets across their stellar disks.

PT - Conference TI - Exoplanet Host Star Characterization with QWSSI AU - van Belle, Gerard AU - Clark, Catherine AU - Horch, Elliott AU - Trilling, David TA - AAS/Division for Extreme Solar Systems Abstracts SO - American Astronomical Society, Extreme Solar Systems 4, id. 330.17. Bulletin of the American Astronomical Society, Vol. 51, No. 6 VI - 51 DP - 2019 Aug 01 PG - 330.17 4099- https://ui.adsabs.harvard.edu/abs/2019ESS.....433017V AB - QWSSI, the Quad-camera Wavefront-Sensing Speckle Imager, is a next- generation speckle imager that is being developed for Lowell Observatory's 4.3-meter Discovery Channel Telescopes. The principle behind QWSSI is to extend the capabilities of the speckle camera currently resident at Lowell, the Differential Speckle Survey Instrument (DSSI), in two ways. First, while DSSI currently observes in two visible channels, QWSSI will simultaneously observe in six narrow-band channels: four in the visible (0.5-0.9um), and one each in J- and H-band (1.2 and 1.6um). Second, the visible light unused for speckle imaging is carefully preserved and feeds a wavefront sensor (WFS), which is also run simultaneously with the speckle imaging. Simulations by Löbb (2016) indicate WFS data will provide significant gains in exploring stellar multiplicity, with marked improvements in primary-secondary contrast ratios and inner working angle (Horch et al. 2018). QWSSI will also be mountable on one of the three 1-meter telescopes being installed on the NPOI Array for engineering tests and preliminary science observations. QWSSI will expand on the already considerable exoplanetary work of the speckle imagers DSSI, NESSI (@ WIYN), Alopeke (Gemini-N), and Zorro (Gemini-S), improving the discovery space for existing targets, as well opening up new regions of that discovery space with its NIR channels.

PT - Conference TI - Understanding the Multiplicity of TESS Exoplanet Host Candidates AU - Clark, Catherine AU - van Belle, Gerard AU - Horch, Elliott AU - von Braun, Kaspar TA - AAS/Division for Extreme Solar Systems Abstracts SO - American Astronomical Society, Extreme Solar Systems 4, id. 316.03. Bulletin of the American Astronomical Society, Vol. 51, No. 6 VI - 51 DP - 2019 Aug 01 PG - 316.03 4099- https://ui.adsabs.harvard.edu/abs/2019ESS.....431603C AB - While at first glance multi-star systems seem quite extreme, they are in fact the most common type of star system in our galaxy, throughout the stellar mass distribution. In particular, 40 to 50% of exoplanet host stars reside within multiple star systems. Given the degree to which initially undetected multiplicity has skewed Kepler results, high- resolution imaging of our nearby low-mass neighbors is necessary for both accurate characterization of transiting exoplanets, as well as a better understanding of stellar astrophysics. To address this frequent gap in our knowledge of exoplanet hosts, we will utilize speckle interferometry to directly image TESS exoplanet host candidates to complete our knowledge of individual star multiplicity. Our investigation will expand upon the speckle observations taken as a part of the POKEMON speckle survey of nearby M-dwarfs to better constrain the multiplicity of low-mass TESS exoplanet host candidates, and to constrain M-dwarf multiplicity by subtype across the entire M-dwarf sequence.

PT - Conference TI - Fundamental Stellar Parameters and Multiplicity Rates of M-Dwarfs through Optical Speckle and NIR AO Imaging AU - Hahne, Frederick AU - Horch, Elliott AU - Ciardi, David R. AU - van Belle, Gerard AU - Clark, Catherine AU - Winters, Jennifer AU - Henry, Todd J. TA - American Astronomical Society Meeting Abstracts #234 SO - American Astronomical Society Meeting #234, id. 303.01. VI - 234 DP - 2019 Jun 01 PG - 303.01 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23430301H AB - We present preliminary fundamental stellar parameters and multiplicity rates of M dwarf stars using a combination of speckle imaging and adaptive optics. Our survey mainly uses the Differential Speckle Survey Instrument (DSSI) at Lowell Observatory's Discovery Channel Telescope (DCT). DSSI observes speckle patterns simultaneously at two separate wavelengths and the data for this project are composed of observations which span from 2016 to 2018. More recently, the speckle data for some of the target stars that have been found to be binary have been supplemented with observations using Adaptive Optics (AO) at Palomar Observatory. The combination of speckle data in the visible and AO data in the near-infrared allows us to make robust determinations of the luminosities and effective temperatures of the components in each case. Using the known Mass-Luminosity Relation, we also estimate the component masses. A discussion of interesting systems will be given.

PT - Journal Article TI - The Future of Exoplanet Direct Detection AU - Monnier, John AU - Rau, Gioia AU - Baines, Ellyn K. AU - Sanchez-Bermudez, Joel AU - Elvis, Martin AU - Ragland, Sam AU - Akeson, Rachel AU - van Belle, Gerard AU - Norris, Ryan AU - Gordon, Kathryn AU - Defrère, Denis AU - Ridgway, Stephen AU - Le Bouquin, Jean-Baptiste AU - Anugu, Narsireddy AU - Scott, Nicholas AU - Kane, Stephen AU - Richardson, Noel AU - Regaly, Zsolt AU - Zhu, Zhaohuan AU - Chiavassa, Andrea AU - Vasisht, Gautam AU - Stassun, Keivan G. AU - Dong, Chuanfei AU - Absil, Olivier AU - Lacour, Sylvestre AU - Weigelt, Gerd AU - Gies, Douglas AU - Adams, Fred C. AU - Calvet, Nuria AU - Quanz, Sascha P. AU - Espaillat, Catherine AU - Gardner, Tyler AU - Greenbaum, Alexandra AU - Millan-Gabet, Rafael AU - Packham, Chris AU - Gai, Mario AU - Kral, Quentin AU - Berger, Jean-Philippe AU - Linz, Hendrik AU - Klarmann, Lucia AU - Bae, Jaehan AU - Lopez Garcia, Rebeca AU - Alexandre, Gallenne AU - Baron, Fabien AU - Hartmann, Lee AU - Kishimoto, Makoto AU - McClure, Melissa AU - Olofsson, Johan AU - Haniff, Chris AU - Line, Michael AU - Petrov, Romain G. AU - Smith, Michael AU - Hummel, Christian AU - ten Brummelaar, Theo AU - De Furio, Matthew AU - Rinehart, Stephen AU - Leisawitz, David AU - Danchi, William AU - Huber, Daniel AU - Wishnow, Edward AU - Mourard, Denis AU - Pope, Benjamin AU - Ireland, Michael AU - Kraus, Stefan AU - Setterholm, Benjamin AU - White, Russel TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, science white papers, no. 514; Bulletin of the American Astronomical Society, Vol. 51, Issue 3, id. 514 (2019) VI - 51 DP - 2019 May 01 PG - 514 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51c.514M AB - Diffraction fundamentally limits our ability to image and characterize exoplanets. Interferometry offers some advantages in exoplanet detection and characterization and we explore in this white paper some of the potential scientific breakthroughs possible.

PT - Journal Article TI - Imaging the Key Stages of Planet Formation AU - Monnier, John AU - Rau, Gioia AU - Bermudez, Joel Sanchez AU - Ragland, Sam AU - Akeson, Rachel AU - Duchene, Gaspard AU - van Belle, Gerard AU - Norris, Ryan AU - Gordon, Kathryn AU - Defrère, Denis AU - Kluska, Jacques AU - Ridgway, Stephen AU - Le Bouquin, Jean-Baptiste AU - Anugu, Narsireddy AU - Scott, Nicholas AU - Kane, Stephen AU - Richardson, Noel D. AU - Regaly, Zsolt AU - Zhu, Zhaohuan AU - Vasisht, Gautam AU - Stassun, Keivan G. AU - Andrews, Sean AU - Lacour, Sylvestre AU - Weigelt, Gerd AU - Turner, Neal AU - Adams, Fred C. AU - Gies, Douglas AU - Calvet, Nuria AU - Espaillat, Catherine AU - Millan-Gabet, Rafael AU - Gardner, Tyler AU - Packham, Chris AU - Gai, Mario AU - Kral, Quentin AU - Berger, Jean-Philippe AU - Linz, Hendrik AU - Klarmann, Lucia AU - Bate, Matthew AU - Bae, Jaehan AU - Lopez, Rebeca Garcia AU - Garufi, Antonio AU - Baron, Fabien AU - Kama, Mihkel AU - Wilner, David AU - Hartmann, Lee AU - Kishimoto, Makoto AU - Olofsson, Johan AU - McClure, Melissa AU - Haniff, Chris AU - Hoenig, Sebastian AU - Line, Michael AU - Petrov, Romain G. AU - Smith, Michael AU - ten Brummelaar, Theo AU - De Furio, Matthew AU - Koutoulaki, Maria AU - Rinehart, Stephen AU - Leisawitz, David AU - Danchi, William AU - Huber, Daniel AU - Zhang, Ke AU - Pope, Benjamin AU - Ireland, Michael AU - Kraus, Stefan AU - Isella, Andrea AU - Setterholm, Benjamin AU - White, Russel TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, science white papers, no. 498; Bulletin of the American Astronomical Society, Vol. 51, Issue 3, id. 498 (2019) VI - 51 DP - 2019 May 01 PG - 498 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51c.498M AB - In this white paper, we explore how higher angular resolution beyond ALMA and 8m-class telescopes can extend our understanding of the key stages of planet formation, to resolve accreting circumplanetary disks themselves, and to watch planets forming in situ for the nearest star- forming regions.

PT - Journal Article TI - Stellar Physics and Galactic Archaeology using Asteroseismology in the 2020's AU - Huber, Daniel AU - Basu, Sarbani AU - Beck, Paul AU - Bedding, Timothy R. AU - Buzasi, Derek AU - Cantiello, Matteo AU - Chaplin, William J. AU - Christiansen, Jessie L. AU - Cunha, Katia AU - Egeland, Ricky AU - Fuller, Jim AU - Garcia, Rafael A. AU - Gies, Douglas R. AU - Guzik, Joyce AU - Hekker, Saskia AU - Hermes, JJ AU - Jackiewicz, Jason AU - Johnson, Jennifer AU - Kawaler, Steve AU - Metcalfe, Travis AU - Mosser, Benoit AU - Ness, Melissa AU - Pinsonneault, Marc AU - Piro, Anthony L. AU - Aguirre, Victor Silva AU - Soderblom, David AU - Stassun, Keivan AU - Tayar, Jamie AU - ten Brummelaar, Theo AU - Roettenbacher, Rachael AU - Trampedach, Regner AU - van Belle, Gerard AU - van Saders, Jennifer AU - Stello, Dennis TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, science white papers, no. 488; Bulletin of the American Astronomical Society, Vol. 51, Issue 3, id. 488 (2019) VI - 51 DP - 2019 May 01 PG - 488 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51c.488H AB - Asteroseismology is the only observational tool in astronomy that can probe the interiors of stars, and is a benchmark method for deriving fundamental properties of stars and exoplanets. In this white paper, we describe key science questions and necessary facilities to continue the asteroseismology revolution into the 2020's.

PT - Journal Article TI - Binary and Multiple Star Systems at High Angular Resolution AU - Schaefer, Gail AU - Duchene, Gaspard AU - Farrington, Christopher D. AU - Gardner, Tyler AU - Gies, Douglas R. AU - Kraus, Adam AU - Monnier, John D. AU - Prato, Lisa AU - Ridgway, Stephen AU - Roettenbacher, Rachael AU - Stencel, Robert E. AU - ten Brummelaar, Theo AU - van Belle, Gerard TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, science white papers, no. 483; Bulletin of the American Astronomical Society, Vol. 51, Issue 3, id. 483 (2019) VI - 51 DP - 2019 May 01 PG - 483 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51c.483S AB - Binary and multiple star systems provide laboratories for measuring stellar masses and studying star formation, stellar evolution, and dynamical evolution over time. This paper outlines several areas in the context of binary stars that can be advanced over the next decade.

PT - Journal Article TI - High Angular Resolution Astrophysics: Fundamental Stellar Parameters AU - van Belle, Gerard AU - Baines, Ellyn AU - Boyajian, Tabetha AU - Gies, Doug AU - Jones, Jeremy AU - Monnier, John AU - Norris, Ryan AU - Roettenbacher, Rachael AU - ten Brummelaar, Theo AU - von Braun, Kaspar AU - White, Russel TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, science white papers, no. 381; Bulletin of the American Astronomical Society, Vol. 51, Issue 3, id. 381 (2019) VI - 51 DP - 2019 May 01 PG - 381 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51c.381V AB - A discussion of direct determination of fundamental stellar parameters, which has many profound and wide-ranging impacts throughout astrophysics.

PT - Journal Article TI - The value of astrometry for exoplanet science AU - Bendek, Eduardo AU - Belikov, Ruslan AU - Guyon, Olivier AU - Currie, Thayne AU - Hasegawa, Yushiro AU - Marley, Mark S. AU - Martin, Stefan AU - Menesson, Bertrand AU - Shao, Michael AU - Turyshev, Slava AU - Vasisht, Gautam AU - Tuthill, Peter AU - McArthur, Barbara E. AU - Rogers, Leslie AU - Van Belle, Gerard TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, science white papers, no. 354; Bulletin of the American Astronomical Society, Vol. 51, Issue 3, id. 354 (2019) VI - 51 DP - 2019 May 01 PG - 354 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51c.354B AB - We describe the scientific importance of measuring exoplanet masses and how high-precision astrometry can be utilized for this purpose. We describe current technology development efforts and astrometry missions concepts being proposed by the community to detect and characterize exoplanets.

PT - Journal Article TI - Precision Analysis of Evolved Stars AU - Ridgway, Stephen AU - Akeson, Rachel AU - Baines, Ellyn AU - Creech-Eakman, Michelle AU - Boyajian, Tabetha AU - De Beck, Elvire AU - Dupree, Andrea AU - Gies, Doug AU - Hinkle, Kenneth AU - Humphreys, Elizabeth AU - Humphreys, Roberta AU - Joyce, Richard AU - Matthews, Lynn AU - Monnier, John AU - Norris, Ryan AU - Roettenbacker, Rachel AU - Stanghellini, Letizia AU - ten Brummellaar, Theo AU - van Belle, Gerard AU - Vlemmings, Wouter AU - Wheeler, J. Craig AU - White, Russell AU - Ziurys, Lucy TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, science white papers, no. 332; Bulletin of the American Astronomical Society, Vol. 51, Issue 3, id. 332 (2019) VI - 51 DP - 2019 May 01 PG - 332 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51c.332R AB - The broad recommendation of this paper is three-fold: recognize the essential role of stellar physics in all of astronomy and cosmology; note that a revolution in stellar measurement capabilities, datasets, and modeling is underway and gaining momentum; and support the scientists, their essential technologies and observatories.

PT - Journal Article TI - Cool, evolved stars: results, challenges, and promises for the next decade AU - Rau, Gioia AU - Montez, Rodolfo, Jr. AU - Carpenter, Kenneth AU - Wittkowski, Markus AU - Bladh, Sara AU - Karovska, Margarita AU - Airapetian, Vladimir AU - Ayres, Tom AU - Boyer, Martha AU - Chiavassa, Andrea AU - Clayton, Geoffrey AU - Danchi, William AU - De Marco, Orsola AU - Dupree, Andrea K. AU - Kaminski, Tomasz AU - Kastner, Joel H. AU - Kerschbaum, Franz AU - Linsky, Jeffrey AU - Lopez, Bruno AU - Monnier, John AU - Montargès, Miguel AU - Nielsen, Krister AU - Ohnaka, Keiichi AU - Ramstedt, Sofia AU - Roettenbacher, Rachael AU - ten Brummelaar, Theo AU - Paladini, Claudia AU - Sarangi, Arkaprabha AU - van Belle, Gerard AU - Ventura, Paolo TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, science white papers, no. 241; Bulletin of the American Astronomical Society, Vol. 51, Issue 3, id. 241 (2019) VI - 51 DP - 2019 May 01 PG - 241 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51c.241R AB - This White Paper identifies compelling scientific opportunities in the field of Cool, Evolved Stars, describing the observational and theoretical challenges to our understanding, and the key advancements made. We portray the pathway towards understanding, and identify, through recommendations, which advancements are necessary in 2020-2030 & beyond.

PT - Journal Article TI - Fundamental Physics with Brown Dwarfs: The Mass-Radius Relation AU - Burgasser, Adam AU - Baraffe, Isabelle AU - Browning, Matthew AU - Burrows, Adam AU - Chabrier, Gilles AU - Creech-Eakman, Michelle AU - Demory, Brice AU - Dieterich, Sergio AU - Faherty, Jacqueline AU - Huber, Daniel AU - Lodieu, Nicolas AU - Plavchan, Peter AU - Rich, R. Michael AU - Saumon, Didier AU - Stassun, Keivan AU - Triaud, Amaury AU - van Belle, Gerard AU - van Grootel, Valerie AU - Vos, Johanna M. AU - Yadav, Rakesh TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, science white papers, no. 214; Bulletin of the American Astronomical Society, Vol. 51, Issue 3, id. 214 (2019) VI - 51 DP - 2019 May 01 PG - 214 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51c.214B AB - The lowest-mass stars, brown dwarfs and giant exoplanets span a minimum in the mass-radius relationship that probes the fundamental physics of extreme states of matter, magnetism, and fusion. This White Paper outlines scientific opportunities and the necessary resources for modeling and measuring the mass- radius relationship in this regime.

PT - Journal Article TI - Observing Planetary Systems in the Making AU - Isella, Andrea AU - Ricci, Luca AU - Andrews, Sean AU - Baruteau, Clement AU - Berger, Jean-Philippe AU - Bergin, Edwin AU - Birnstiel, Til AU - Bowler, Brendan AU - Brogan, Crystal AU - Carrasco Gonzalez, Carlos AU - Chandler, Claire AU - Currie, Thayne AU - Cuzzi, Jeffrey AU - D'Angelo, Gennaro AU - Dong, Ruobing AU - Duchene, Gaspard AU - Dutrey, Anne AU - Ercolano, Barbara AU - Espaillat, Catherine AU - Estrada, Paul AU - Flock, Mario AU - Gaspar, Andras AU - Greene, Thomas P. AU - Huang, Jane AU - Jang-Condell, Hannah AU - Johns-Krull, Christopher AU - Kennedy, Grant AU - Kim, J. Serena AU - Kirchschlager, Florian AU - Kraus, Stefan AU - Krijt, Sebastiaan AU - Li, Hui AU - Lyra, Wladimir AU - Macintosh, Bruce AU - Monnier, John AU - Oberg, Karin AU - Pascucci, Ilaria AU - Perez, Laura AU - Petrov, Romain AU - Pinilla, Paola AU - Ridgway, Stephen AU - Stassun, Keivan AU - ten Brummelaar, Theo AU - Testi, Leonardo AU - Turner, Neal J. AU - Van Belle, Gerard AU - van der Marel, Nienke AU - Weinberger, Alycia AU - White, Jacob AU - Williams, Jonathan AU - Wilner, David AU - Wootten, Alwyn AU - Wu, Ya-Lin AU - Youdin, Andrew AU - Zhang, Ke AU - Zhu, Zhaohuan TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, science white papers, no. 174; Bulletin of the American Astronomical Society, Vol. 51, Issue 3, id. 174 (2019) VI - 51 DP - 2019 May 01 PG - 174 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51c.174I AB - We discuss science cases to support the development of sub-au imaging capabilities to image forming planets in the terrestrial region of nearby proto-planetary disks.

PT - Journal Article TI - Stars at High Spatial Resolution AU - Carpenter, Kenneth AU - van Belle, Gerard AU - Brown, Alexander AU - Cranmer, Steven R. AU - Drake, Jeremy AU - Dupree, Andrea K. AU - Creech-Eakman, Michelle AU - Evans, Nancy R. AU - Grady, Carol A. AU - Guinan, Edward F. AU - Harper, Graham AU - Karovska, Margarita AU - Kolenberg, Katrien AU - Labeyrie, Antoine AU - Linsky, Jeffrey AU - Peters, Geraldine J. AU - Rau, Gioia AU - Ridgway, Stephen AU - Roettenbacher, Rachael M. AU - Saar, Steven H. AU - Walter, Frederick M. AU - Wood, Brian TA - Bulletin of the American Astronomical Society SO - Astro2020: Decadal Survey on Astronomy and Astrophysics, science white papers, no. 56; Bulletin of the American Astronomical Society, Vol. 51, Issue 3, id. 56 (2019) VI - 51 DP - 2019 May 01 PG - 56 4099- https://ui.adsabs.harvard.edu/abs/2019BAAS...51c..56C AB - We summarize compelling new scientific opportunities for understanding stars and stellar systems that can be enabled by sub-milliarcsec angular resolution, UV/Optical spectral imaging observations. These can reveal details of many dynamic processes that affect stellar formation, structure, and evolution.

PT - Conference TI - Developing Low-Cost Adaptive Optics Telescopes for Long Baseline Optical Interferometry AU - Heilman, Micha AU - van Belle, Gerard AU - Clark, Jim AU - Depinet, Jon TA - American Astronomical Society Meeting Abstracts #233 SO - American Astronomical Society, AAS Meeting #233, id.462.07 VI - 233 DP - 2019 Jan 01 PG - 462.07 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23346207H AB - Our research examines the use of adaptive optics (AO) in tandem with low-quality optics to determine if diffraction limited results can be achieved using active corrective optics. The 1μm scale of wavefront corrections provided by AO systems are substantially greater than the ~50nm construction specifications of typical telescopes. Thus, this pairing of optics and software could increase image quality while decreasing cost by significantly (~20x) relaxing mechanical requirements. As a baseline, we measured a 6in lab-quality flat with a Zygo interferometer, an instrument built for surface inspection of diffraction-limited optics. To contrast this result, we similarly inspected a low-quality mirror. We found roughly 2 full waves, about 1μm, of smoothly varying static wavefront distortion across the ~5in Zygo inspection aperture. Our lab setup consisted of a Thorlabs AO Kit (model 7) with light source, deformable mirror (DM), and Shack-Hartman wavefront sensor (WFS). A 2.5cm beam expanded from a 0.34mW laser diode hit the low-quality mirror, which retroreflected into the AO system and was re-collimated to 5mm to match the sensor diameter of the WFS. Fifteen data sets were collected to find the Peak-to-Valley (PV) and root-mean-square (rms) of the wavefront measured from the low-quality mirror and the reconstructed wavefront corrected by the DM. This second data set was used to calculate the difference between the measured and reconstructed wavefronts. The process was repeated by replacing the low- quality mirror with a lab-quality mirror rated to λ/20. The PV measurement for the low-quality mirror was 55μm with a rms of 12.7μm, compared to the lab-quality mirror whose PV was 53μm with a rms of 10.8μm. The difference between the low-quality mirror's wavefront and the DM reconstructed wavefront was a PV of 0.21μm with a rms of 0.04μm. The resultant wavefront corrected 80% past it's predicted outcome of 1μm. Our results indicate it would be advantageous to use a telescope design that assumes integral AO from the outset; further benefits come from tailoring the telescopes to the narrow set of specifications that emphasize use in a narrow-angle long-baseline optical interferometry system.

PT - Conference TI - The SUPERWIDE Catalog of Wide Binaries and an Initial Look at the Higher Order Multiplicity of K and M dwarf Wide Binaries AU - Hartman, Zachary AU - van Belle, Gerard AU - Lepine, Sebastien AU - Clark, Catherine TA - American Astronomical Society Meeting Abstracts #233 SO - American Astronomical Society, AAS Meeting #233, id.418.03 VI - 233 DP - 2019 Jan 01 PG - 418.03 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23341803H AB - We present the SUPERWIDE catalog of wide binaries that were identified through a Bayesian analysis of high proper motions stars (m>40 mas/yr) from the Gaia DR2 catalog. Initially identified through an earlier search of the SUPERBLINK high proper motion catalog, these binaries were found by their proximity on the sky, common proper motion and similar distances. Taking those pairs with a probability of being a "true" binary (i.e. gravitationally bound system) greater than 99%, we identify ~22,000 wide binaries with projected physical separations between ~100 AU to ~1 pc. We present initial results of an ongoing speckle survey of these wide binaries devoted to the identification of higher order multiples. Using data collected through the POKEMON M-dwarf multiplicity survey, we have examined ~15 wide binaries to see if they are in fact triple or quadruple systems. With this information and more to come, we intend to determine the higher order multiplicity fraction for K and M dwarf wide binaries as a function of their physical separation in order to provide constraints for the possible formation mechanisms of these wide systems.

PT - Conference TI - The POKEMON Speckle Survey of Nearby M-dwarfs AU - Clark, Catherine AU - van Belle, Gerard AU - Horch, Elliott AU - von Braun, Kaspar TA - American Astronomical Society Meeting Abstracts #233 SO - American Astronomical Society, AAS Meeting #233, id.259.03 VI - 233 DP - 2019 Jan 01 PG - 259.03 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23325903C AB - The POKEMON (Pervasive Overview of Kompanions of Every M-dwarf in Our Neighborhood) survey of nearby M-dwarfs intends to inspect, at diffraction-limited resolution, every low-mass star out to 15pc, along with selected additional objects to 25pc. The primary emphasis of the survey is the detection of low-mass companions to these M-dwarfs for refinement of the low-mass star multiplicity rate. Given the priority these targets will have for upcoming exoplanet studies using TESS and JWST - and the degree to which initially undetected multiplicity has affected Kepler results - a comprehensive survey of our nearby low-mass neighbors will produce a homogenous, complete catalog of fundamental utility. Prior knowledge of those secondary objects - or robust non- detections, as will be captured by this survey - will help immediately clarify the nature of exoplanet transit detections from these current and upcoming missions. POKEMON is using Lowell Observatory's 4.3-m Discovery Channel Telescope (DCT) with the Differential Speckle Survey Instrument (DSSI) speckle camera, along with the NN-Explore Exoplanet Stellar Speckle Imager (NESSI) speckle imager on 3.5-m WIYN; the survey takes advantage of the extremely rapid observing cadence rates possible with WIYN and (especially) DCT. The current status and results are from the first 20+ nights of observing.

PT - Conference TI - Optimast Structurally Connected Interferometry Enabled by In-Space Robotic Manufacturing and Assembly AU - van Belle, Gerard AU - Patané, Simon AU - Riley, Daniel AU - Fagin, Max AU - Paul-Gin, Noah AU - Schomer, Jack AU - Snyder, Mike TA - American Astronomical Society Meeting Abstracts #233 SO - American Astronomical Society, AAS Meeting #233, id.158.25 VI - 233 DP - 2019 Jan 01 PG - 158.25 4099- https://ui.adsabs.harvard.edu/abs/2019AAS...23315825V AB - Future goals for astrophysics at the frontiers of high spatial resolution drive the need for large effective apertures beyond what the current generation of space observatories provides. Space-based interferometry delivers on this promise and enables cost-effective observation of faint objects at unprecedented levels of angular resolution. Using the Made In Space (MIS) Optimast capability, a simple, two aperture Structurally Connected Interferometer (SCI) is produced via in-space Additive Manufacturing (AM) technology. This capability allows the two modest apertures to be packaged efficiently for launch and then placed at a large separation, coherently, in order to achieve a greater effective angular resolution . Optimast enables the manufacturing and deployment of large primary trusses unconstrained by launch loads or volume restrictions that meet science requirements for the high angular resolutions (in the milliarcsecond regime) necessary for applications such as characterization of planets near bright stars, and measurement individual objects in dense star clusters. Space-based deployment of an interferometer unfettered by the turbulent atmosphere will markedly increase the sensitivity reach of such an instrument relative to its ground-based counterparts. Adapting the MIS Optimast technology to produce long baseline structures with low thermal expansion materials enables simultaneous structural fabrication and positioning of the optical subsystems to the required static, thermal deflection, and oscillation tolerances. An Optimast-SCI baseline structure eliminates parasitic mass and provides superior absolute position control over traditional deployable structures at much lower cost, mass, and integration complexity.

PT - Conference TI - The Gaia-based prediction of the 2019 May 1 occultation of elongated KBO (33128) 1998 BU48 AU - Young, Leslie AU - Porter, Simon AU - Keeny, Brian AU - Sheppard, Scott AU - Thirouin, Audrey AU - Wasserman, Lawrence AU - Tholen, David AU - Tanga, Paulo AU - Terrell, Dirk AU - Schwamb, Megan AU - Buie, Marc AU - Cobble, Kevin AU - Young, Eliot AU - Reyes Ruiz, Mauricio AU - Bobbick, Dick AU - Castro-Chacon, Joel AU - Tobias, Bryan AU - Dunham, David AU - Keller, John AU - Leiva, Rodrigo TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-1321 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-1321 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13.1321Y AB - Gaia should enable the Golden Age of stellar occultations. We planned for an occultation by elongated KBO 1998 BU48, with no positive reported events yet. We will study this example to improve future Gaia-enabled occultations.

PT - Conference TI - Stellar Occultation Results for (486958) 2014MU69: A Pathfinding Effort for the New Horizons Flyby AU - Buie, M. W. AU - Porter, S. B. AU - Tamblyn, P. AU - Terrell, D. AU - Verbiscer, A. J. AU - Keeney, B. AU - Zangari, A. M. AU - Wasserman, L. H. AU - Ocampo, A. AU - Stern, S. A. AU - New Horizons Occultation Team TA - Lunar and Planetary Science Conference SO - 50th Lunar and Planetary Science Conference, held 18-22 March, 2019 at The Woodlands, Texas. LPI Contribution No. 2132, id.3120 DP - 2019 Mar 01 PG - 3120 4099- https://ui.adsabs.harvard.edu/abs/2019LPI....50.3120B AB - Four occultations were observed by 2014MU69 and the results were invaluable for mission planning and execution of the New Horizons flyby on 2019 Jan 1.

PT - Conference TI - A Potential New Surface Type in the Kuiper Belt AU - Schwamb, Megan AU - Fraser, Wesley AU - Bannister, Michele AU - Marsset, Michaël AU - Pike, Rosemary AU - Kavelarrs, Jj AU - Benecchi, Susan AU - Lehner, Matthew AU - Wang, Shiang-Yu AU - Thirouin, Audrey AU - Peixinho, Nuno AU - Volk, Kathryn AU - Alexandersen, Mike AU - Chen, Ying-Tung AU - Gladman, Brett AU - Gwyn, Stephen AU - Petit, Jean-Marc TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-1271 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-1271 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13.1271S AB - Colours of the Outer Solar System Origins Survey (Col-OSSOS) is probing Kuiper belt object (KBO) surface properties via near simultaneous g,r and J photometry from Gemini North with additional u-band imaging from CFHT. We will present the latest results from the survey including the surface properties of two outlier objects from the Col-OSSOS color distribution that may represent a new surface type present within the small KBO population.

PT - Conference TI - Col-OSSOS: A Compositional Interpretation of Kuiper Belt Spectra AU - Fraser, Wesley AU - Schwamb, Megan AU - Bannister, Michele AU - Marsset, Michael AU - Pike, Rosemary AU - Kavelaars, Jj AU - Benecchi, Susan AU - Lehner, Matthew AU - Wang, Shiang-yu AU - Thirouin, Audrey AU - Peixinho, Nuno AU - Volk, Kathryn AU - Alexandersen, Mike AU - Chen, Ying-tung AU - Gladman, Brett AU - Gwyn, Stephen AU - Petit, Jean-marc TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-1206 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-1206 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13.1206F AB - We propose a new compositional model for Kuiper Belt Objects that can account for many of the observed properties of those bodies, including their colour, and spectral behaviour. This model successfully accounts for the links to other related bodies, including the satellite Phoebe. The model asserts that the majority of KBOs consist of reddened carbonaceous material. If true, this implies that neutral class KBOs share a primordial link with the carbonaceous asteroids, the same bodies that scattered in to become the C-types in the asteroid belt.

PT - Conference TI - Contact binaries in the trans-Neptunian population: location, physical and rotational properties. AU - Thirouin, Audrey AU - Sheppard, Scott S. TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-657 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-657 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..657T AB - We are searching for and characterizing contact binaries in the trans- Neptunian populations through an extensive survey with the 4.3 m Lowell's Discovery Channel Telescope and the 6.5 m Magellan-Baade telescope. We aim to derive their rotational and physical properties, to constrain their fractions in several sub-populations of trans-Neptunian objects, understand their formation and evolution as well as improve our knowledge of the binary population and by extension the entire trans- Neptunian belt

PT - Conference TI - Characterization of Active Asteroid (6478) Gault AU - Sanchez, Juan AU - Reddy, Vishnu AU - Thirouin, Audrey AU - Wright, Edward AU - Linder, Tyler AU - Sharkey, Benjamin TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-344 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-344 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..344S AB - Here we report the results from our rotational and spectral characterization of main belt active asteroid (6478) Gault. Based on three nights of observations, we could not confirm the rotation period of 2 h for Gault reported in previous work, as no obvious variability in the lightcurves was found. NIR spectroscopic data obtained with the IRTF showed a spectrum similar to that of S-type asteroids, and a composition consistent with H chondrite meteorites. These results favor a compositional affinity between Gault and the Phocaea family.

PT - Conference TI - A photometric and spectroscopic study of the multi-tailed asteroid (6478) Gault AU - Jehin, Emmanuel AU - Moreno, Fernando AU - Ferrais, Marin AU - Pozuelos, Francisco J. AU - Licandro, Javier AU - Moulane, Youssef AU - Devogele, Maxime AU - Manfroid, Jean AU - Benkhaldoun, Zouhair AU - Snodgrass, Colin TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-1826 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-1826 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13.1826J AB - In this presentation, we describe several months of monitoring of Gault since January 2019 using various telescopes and instrumentation. The goal is to characterize and to model the asteroids and the tails to impose constraints on the physical properties of the ejected dust, and to shed light on the activity timeline and the causes for the ejection events.

PT - Conference TI - Deep Ecliptic Exploration Project (DEEP) Observing Strategy AU - Trujillo, Chad AU - Trilling, David AU - Gerdes, David AU - Holman, Matthew AU - Markwardt, Larissa AU - Sheppard, Scott AU - Fuentes, Cesar AU - Juric, Mario AU - Lin, Edward AU - McNeill, Andrew AU - Mommert, Michael AU - Oldroyd, William AU - Payne, Matthew AU - Ragozzine, Darin AU - Rivkin, Andrew AU - Schlichting, Hilke AU - Schwamb, Megan TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-2070 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-2070 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13.2070T AB - We present the Deep Ecliptic Exploration Project (DEEP) survey strategy including observing cadence for orbit determination, exposure times, field pointings and filter choices. The overall goal of the survey is to discover and characterize the orbits of several thou- sand Trans- Neptunian Objects (TNOs) using the Dark Energy Camera (DECam) on the Cerro Tololo Inter- American Observatory Blanco 4 meter telescope. When complete, DEEP will be the largest survey of the outer solar sys- tem ever undertaken in terms of object numbers and will also be among the deepest.

PT - Conference TI - The Deep Ecliptic Exploration Project (DEEP): A new NOAO survey of the faint outer Solar System AU - Trilling, David AU - Gerdes, David AU - Trujillo, Chad AU - Sheppard, Scott AU - Fuentes, Cesar AU - Schlichting, Hilke AU - McNeill, Andrew AU - Juric, Mario AU - Holman, Matt AU - Lin, Ed AU - Markwardt, Larissa AU - Mommert, Michael AU - Oldroyd, William AU - Payne, Matt AU - Ragozzine, Darin AU - Rivkin, Andrew AU - Schwamb, Megan TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-395 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-395 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..395T AB - We have begun a new survey progam to carry out a deep search of the faint outer Solar System with the Dark Energy Camera and the 4-meter Blanco telescope at the Cerro Tololo Inter-American Observatory in Chile. We will measure the size distribution and physical properties of 5000 very faint Kuiper Belt Objects (KBOs). We will measure the size distribution, colors, and shape distribution of KBOs as a function of their orbital properties. Our data set will also allow us to measure the colors, size distribution, and shape distribution of main belt asteroids, and enable a rich array of other science investigations. Our results will help elucidate the composition and structure of the outer Solar System and the origin of our planetary system.

PT - Conference TI - Investigating Taxonomic Diversity of the Main Belt through KMTNET-SAAO and ATLAS Multi-band Photometry AU - Erasmus, Nicolas AU - McNeill, Andrew AU - Mommert, Michael AU - Trilling, David E. AU - Sickafoose, Amanda. A. AU - Paterson, Kerry AU - Navarro-Meza, Samuel AU - Denneau, Larry AU - Flewelling, Heather AU - Heinze, Aren AU - Tonry, John. L. TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-147 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-147 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13..147E AB - We present multi-band photometry from the South Africa node of the Korea Microlensing Telescope Network (KMTNet-SAAO) and the Asteroid Terrestrial-impact Last Alert System (ATLAS) which we use to classify several thousand main-belt asteroids with the Bus-DeMeo taxonomic scheme. We use our determined taxonomies to investigating the taxonomic diversity of the Main Belt and in particular the diversity observed in the Flora family.

PT - Conference TI - Makemake's thermal emission reconsidered AU - Farkas-Takacs, Anikó AU - Kiss, Csaba AU - Müller, Thomas AU - Mommert, Michael TA - EPSC-DPS Joint Meeting 2019 SO - EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-86 VI - 2019 DP - 2019 Sep 01 PG - EPSC-DPS2019-86 4099- https://ui.adsabs.harvard.edu/abs/2019EPSC...13...86F AB - Makemake, one of the officially recognised dwarf planets in the Kuiper belt, has a bright surface with a geometric albedo >80% as determined from occultation observations . Makemake's thermal emission was measured with various instruments, including the MIPS camera of the Spitzer Space Telescope, the PACS and SPIRE instruments of the Herschel Space Observatory and the submm emission with ALMA . According to these measurements the thermal emission cannot be fitted with a single body with a single terrain - the high 24 and 70um flux densities requires the presence of a 'dark terrain', either on the surface of Makemake or on an external source (e.g. a dark satellite). However, even these dark terrains cannot fully explain the observed flux densities. Here we present a partial re-evaluation of previous Spitzer/MIPS and Herschel/PACS data using the latest calibration and data reduction pipeline, and also include so far unpublished Spitzer/MIPS 24/70 and Herschel/PACS 70, 100 and 160um measurements. We model the thermal emission considering the rotation of Makemake, its possible shapes and spin axis orientations, mass, and possible contribution from known and suspected satellites. Our evaluation provides the most complete picture on the thermal emission of this dwarf planet.-

PT - Journal Article TI - MGS-TES Spectra of Phobos Indicate Thermally Homogeneous Surface AU - Smith, N. M. AU - Edwards, C. S. AU - Mommert, M. AU - Trilling, D. E. AU - Glotch, T. D. TA - LPI Contributions SO - Ninth International Conference on Mars, held 22-25 July, 2019 in Pasadena, California. LPI Contribution No. 2089, id.6391 VI - 2089 DP - 2019 Jul 01 PG - 6391 4099- https://ui.adsabs.harvard.edu/abs/2019LPICo2089.6391S AB - We present a map of the thermal inertia of the surface of Phobos, based on observations collected by Mars Global Surveyor using the Thermal Emission Spectrometer (TES) instrument. We find a fairly uniform thermal inertia across the observed region.