Spatial Interferometry in Optical Astronomy
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Lurking in the Shadows: Wide-Separation Gas Giants As Tracers of Planet Formation
Lurking in the Shadows: Wide-Separation Gas Giants as Tracers of Planet Formation Thesis by Marta Levesque Bryan In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy CALIFORNIA INSTITUTE OF TECHNOLOGY Pasadena, California 2018 Defended May 1, 2018 ii © 2018 Marta Levesque Bryan ORCID: [0000-0002-6076-5967] All rights reserved iii ACKNOWLEDGEMENTS First and foremost I would like to thank Heather Knutson, who I had the great privilege of working with as my thesis advisor. Her encouragement, guidance, and perspective helped me navigate many a challenging problem, and my conversations with her were a consistent source of positivity and learning throughout my time at Caltech. I leave graduate school a better scientist and person for having her as a role model. Heather fostered a wonderfully positive and supportive environment for her students, giving us the space to explore and grow - I could not have asked for a better advisor or research experience. I would also like to thank Konstantin Batygin for enthusiastic and illuminating discussions that always left me more excited to explore the result at hand. Thank you as well to Dimitri Mawet for providing both expertise and contagious optimism for some of my latest direct imaging endeavors. Thank you to the rest of my thesis committee, namely Geoff Blake, Evan Kirby, and Chuck Steidel for their support, helpful conversations, and insightful questions. I am grateful to have had the opportunity to collaborate with Brendan Bowler. His talk at Caltech my second year of graduate school introduced me to an unexpected population of massive wide-separation planetary-mass companions, and lead to a long-running collaboration from which several of my thesis projects were born. -
Dust and Gas in the Disk of Hl Tauri: Surface Density, Dust Settling, and Dust-To-Gas Ratio C
The Astrophysical Journal, 816:25 (12pp), 2016 January 1 doi:10.3847/0004-637X/816/1/25 © 2016. The American Astronomical Society. All rights reserved. DUST AND GAS IN THE DISK OF HL TAURI: SURFACE DENSITY, DUST SETTLING, AND DUST-TO-GAS RATIO C. Pinte1,2, W. R. F. Dent3, F. Ménard1,2, A. Hales3,4, T. Hill3, P. Cortes3,4, and I. de Gregorio-Monsalvo3 1 UMI-FCA, CNRS/INSU, France (UMI 3386), and Dept. de Astronomía, Universidad de Chile, Santiago, Chile; [email protected] 2 Univ. Grenoble Alpes, IPAG, F-38000 Grenoble, France CNRS, IPAG, F-38000 Grenoble, France 3 Atacama Large Millimeter/Submillimeter Array, Joint ALMA Observatory, Alonso de Córdova 3107, Vitacura 763-0355, Santiago, Chile 4 National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475, USA Received 2015 March 22; accepted 2015 September 8; published 2015 December 29 ABSTRACT The recent ALMA observations of the disk surrounding HL Tau reveal a very complex dust spatial distribution. We present a radiative transfer model accounting for the observed gaps and bright rings as well as radial changes of the emissivity index. We find that the dust density is depleted by at least a factor of 10 in the main gaps compared to the surrounding rings. Ring masses range from 10–100 M⊕ in dust, and we find that each of the deepest gaps is consistent with the removal of up to 40 M⊕ of dust. If this material has accumulated into rocky bodies, these would be close to the point of runaway gas accretion. -
Naming the Extrasolar Planets
Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named. -
The NTT Provides the Deepest Look Into Space 6
The NTT Provides the Deepest Look Into Space 6. A. PETERSON, Mount Stromlo Observatory,Australian National University, Canberra S. D'ODORICO, M. TARENGHI and E. J. WAMPLER, ESO The ESO New Technology Telescope r on La Silla has again proven its extraor- - dinary abilities. It has now produced the "deepest" view into the distant regions of the Universe ever obtained with ground- or space-based telescopes. Figure 1 : This picture is a reproduction of a I.1 x 1.1 arcmin portion of a composite im- age of forty-one 10-minute exposures in the V band of a field at high galactic latitude in the constellation of Sextans (R.A. loh 45'7 Decl. -0' 143. The individual images were obtained with the EMMI imager/spectrograph at the Nas- myth focus of the ESO 3.5-m New Technolo- gy Telescope using a 1000 x 1000 pixel Thomson CCD. This combination gave a full field of 7.6 x 7.6 arcmin and a pixel size of 0.44 arcsec. The average seeing during these exposures was 1.0 arcsec. The telescope was offset between the indi- vidual exposures so that the sky background could be used to flat-field the frame. This procedure also removed the effects of cos- mic rays and blemishes in the CCD. More than 97% of the objects seen in this sub- field are galaxies. For the brighter galax- ies, there is good agreement between the galaxy counts of Tyson (1988, Astron. J., 96, 1) and the NTT counts for the brighter galax- ies. -
SEPTEMBER 2014 OT H E D Ebn V E R S E R V ESEPTEMBERR 2014
THE DENVER OBSERVER SEPTEMBER 2014 OT h e D eBn v e r S E R V ESEPTEMBERR 2014 FROM THE INSIDE LOOKING OUT Calendar Taken on July 25th in San Luis State Park near the Great Sand Dunes in Colorado, Jeff made this image of the Milky Way during an overnight camping stop on the way to Santa Fe, NM. It was taken with a Canon 2............................. First quarter moon 60D camera, an EFS 15-85 lens, using an iOptron SkyTracker. It is a single frame, with no stacking or dark/ 8.......................................... Full moon bias frames, at ISO 1600 for two minutes. Visible in this south-facing photograph is Sagittarius, and the 14............ Aldebaran 1.4˚ south of moon Dark Horse Nebula inside of the Milky Way. He processed the image in Adobe Lightroom. Image © Jeff Tropeano 15............................ Last quarter moon 22........................... Autumnal Equinox 24........................................ New moon Inside the Observer SEPTEMBER SKIES by Dennis Cochran ygnus the Swan dives onto center stage this other famous deep-sky object is the Veil Nebula, President’s Message....................... 2 C month, almost overhead. Leading the descent also known as the Cygnus Loop, a supernova rem- is the nose of the swan, the star known as nant so large that its separate arcs were known Society Directory.......................... 2 Albireo, a beautiful multi-colored double. One and named before it was found to be one wide Schedule of Events......................... 2 wonders if Albireo has any planets from which to wisp that came out of a single star. The Veil is see the pair up-close. -
Condensation of the Solar Nebular
Formation of the Sun-like Stars • Collapse of a portion of a molecular cloud 4.5-4.6 Ga – Star dusts in primitive meteorites provide – Fingerprints of neaby stars that preceded our Sun – Stars like our Sun can form in a large number (hundreds to thousands) and close to each other (0.1 pc or ~0.3 lightyear, much closer than the Sun’s neighbor stars) as seen in the Orion Nebular. – Modern molecular clouds also has circumstellar disks, where planets form. – Gas in the molecular clouds is cold (~4K) and relatively dense (104 atoms/cm3). 1 Formation of the Sun-like Stars • Young stars emits more infrared radiation than a blackbody of the same size –Due to dark (opaque) disks around them. –Such disks are dubbed “proplyds” (proto-planetary disks). • Planets in the solar system orbit the Sun in the same direction and the orbits are roughly coplanar. –Suggests the solar system originated from a disk-shaped region of material referred to as the solar nebular. –An old idea conceived at least 2 centuries ago. –Discovery of proplyds now provide strong support. 2 Formation of the Sun-like Stars • Not clear what triggers the collapse of the densest portion of the cloud (“core”) to form stars. – Sequential ages of stars in close proximity in a molecular cloud suggests that formation and evolution of some stars trigger the formation of additional stars. • Gas around the collapsing core of the molecular cloud is moving – Too much angular momentum binary star – Otherwise, a single protostar called a T Tauri star or a pre-main sequence star. -
Occurrence and Core-Envelope Structure of 1–4× Earth-Size Planets Around Sun-Like Stars
Occurrence and core-envelope structure of 1–4× SPECIAL FEATURE Earth-size planets around Sun-like stars Geoffrey W. Marcya,1, Lauren M. Weissa, Erik A. Petiguraa, Howard Isaacsona, Andrew W. Howardb, and Lars A. Buchhavec aDepartment of Astronomy, University of California, Berkeley, CA 94720; bInstitute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822; and cHarvard-Smithsonian Center for Astrophysics, Harvard University, Cambridge, MA 02138 Edited by Adam S. Burrows, Princeton University, Princeton, NJ, and accepted by the Editorial Board April 16, 2014 (received for review January 24, 2014) Small planets, 1–4× the size of Earth, are extremely common planets. The Doppler reflex velocity of an Earth-size planet − around Sun-like stars, and surprisingly so, as they are missing in orbiting at 0.3 AU is only 0.2 m s 1, difficult to detect with an − our solar system. Recent detections have yielded enough informa- observational precision of 1 m s 1. However, such Earth-size tion about this class of exoplanets to begin characterizing their planets show up as a ∼10-sigma dimming of the host star after occurrence rates, orbits, masses, densities, and internal structures. coadding the brightness measurements from each transit. The Kepler mission finds the smallest planets to be most common, The occurrence rate of Earth-size planets is a major goal of as 26% of Sun-like stars have small, 1–2 R⊕ planets with orbital exoplanet science. With three years of Kepler photometry in periods under 100 d, and 11% have 1–2 R⊕ planets that receive 1–4× hand, two groups worked to account for the detection biases in the incident stellar flux that warms our Earth. -
In-Depth Study of Photometric Variability and Radiative Timescales for Atmospheric Evolution in Four L Dwarfs
Weather on Other Worlds IV: In-Depth Study of Photometric Variability and Radiative Timescales for Atmospheric Evolution in Four L Dwarfs Item Type text; Electronic Thesis Authors Flateau, Davin C. Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 30/09/2021 07:25:39 Link to Item http://hdl.handle.net/10150/594630 WEATHER ON OTHER WORLDS IV: IN-DEPTH STUDY OF PHOTOMETRIC VARIABILITY AND RADIATIVE TIMESCALES FOR ATMOSPHERIC EVOLUTION IN FOUR L DWARFS by Davin C. Flateau A Thesis Submitted to the Faculty of the DEPARTMENT OF PLANETARY SCIENCES In Partial Fulfillment of the Requirements For the Degree of MASTER OF SCIENCE In the Graduate College THE UNIVERSITY OF ARIZONA 2015 2 STATEMENT BY AUTHOR This thesis has been submitted in partial fulfillment of requirements for an advanced degree at the University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledgment of the source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his or her judgment the proposed use of the material is in the interests of scholarship. -
Abstracts Connecting to the Boston University Network
20th Cambridge Workshop: Cool Stars, Stellar Systems, and the Sun July 29 - Aug 3, 2018 Boston / Cambridge, USA Abstracts Connecting to the Boston University Network 1. Select network ”BU Guest (unencrypted)” 2. Once connected, open a web browser and try to navigate to a website. You should be redirected to https://safeconnect.bu.edu:9443 for registration. If the page does not automatically redirect, go to bu.edu to be brought to the login page. 3. Enter the login information: Guest Username: CoolStars20 Password: CoolStars20 Click to accept the conditions then log in. ii Foreword Our story starts on January 31, 1980 when a small group of about 50 astronomers came to- gether, organized by Andrea Dupree, to discuss the results from the new high-energy satel- lites IUE and Einstein. Called “Cool Stars, Stellar Systems, and the Sun,” the meeting empha- sized the solar stellar connection and focused discussion on “several topics … in which the similarity is manifest: the structures of chromospheres and coronae, stellar activity, and the phenomena of mass loss,” according to the preface of the resulting, “Special Report of the Smithsonian Astrophysical Observatory.” We could easily have chosen the same topics for this meeting. Over the summer of 1980, the group met again in Bonas, France and then back in Cambridge in 1981. Nearly 40 years on, I am comfortable saying these workshops have evolved to be the premier conference series for cool star research. Cool Stars has been held largely biennially, alternating between North America and Europe. Over that time, the field of stellar astro- physics has been upended several times, first by results from Hubble, then ROSAT, then Keck and other large aperture ground-based adaptive optics telescopes. -
Graham Pointer Phd Thesis
THE MAGNETIC FIELD OF AB DORADÛS Graham Richard Pointer A Thesis Submitted for the Degree of PhD at the University of St Andrews 2001 Full metadata for this item is available in St Andrews Research Repository at: http://research-repository.st-andrews.ac.uk/ Please use this identifier to cite or link to this item: http://hdl.handle.net/10023/12940 This item is protected by original copyright THE UNIVERSITY OF ST. ANDREWS The Magnetic Field of AB Doradûs Graham Richard Pointer Submitted for the degree of Ph.D. May 2001 ProQuest Number: 10171062 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a com plete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest ProQuest 10171062 Published by ProQuest LLO (2017). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States C ode Microform Edition © ProQuest LLO. ProQuest LLO. 789 East Eisenhower Parkway P.Q. Box 1346 Ann Arbor, Ml 48106- 1346 DECLARATION I, Graham Richard Pointer, hereby declare that this thesis, which is approximately 50000 words in length, has been written by me, that it is the record of work carried out by me and that it has not been submitted in any previous application for a higher degree. I was admitted as a research student in September 1997 and as a candidate for the degree of Ph.D . -
A Review on Substellar Objects Below the Deuterium Burning Mass Limit: Planets, Brown Dwarfs Or What?
geosciences Review A Review on Substellar Objects below the Deuterium Burning Mass Limit: Planets, Brown Dwarfs or What? José A. Caballero Centro de Astrobiología (CSIC-INTA), ESAC, Camino Bajo del Castillo s/n, E-28692 Villanueva de la Cañada, Madrid, Spain; [email protected] Received: 23 August 2018; Accepted: 10 September 2018; Published: 28 September 2018 Abstract: “Free-floating, non-deuterium-burning, substellar objects” are isolated bodies of a few Jupiter masses found in very young open clusters and associations, nearby young moving groups, and in the immediate vicinity of the Sun. They are neither brown dwarfs nor planets. In this paper, their nomenclature, history of discovery, sites of detection, formation mechanisms, and future directions of research are reviewed. Most free-floating, non-deuterium-burning, substellar objects share the same formation mechanism as low-mass stars and brown dwarfs, but there are still a few caveats, such as the value of the opacity mass limit, the minimum mass at which an isolated body can form via turbulent fragmentation from a cloud. The least massive free-floating substellar objects found to date have masses of about 0.004 Msol, but current and future surveys should aim at breaking this record. For that, we may need LSST, Euclid and WFIRST. Keywords: planetary systems; stars: brown dwarfs; stars: low mass; galaxy: solar neighborhood; galaxy: open clusters and associations 1. Introduction I can’t answer why (I’m not a gangstar) But I can tell you how (I’m not a flam star) We were born upside-down (I’m a star’s star) Born the wrong way ’round (I’m not a white star) I’m a blackstar, I’m not a gangstar I’m a blackstar, I’m a blackstar I’m not a pornstar, I’m not a wandering star I’m a blackstar, I’m a blackstar Blackstar, F (2016), David Bowie The tenth star of George van Biesbroeck’s catalogue of high, common, proper motion companions, vB 10, was from the end of the Second World War to the early 1980s, and had an entry on the least massive star known [1–3]. -
Publication List for Amaury H.M.J. Triaud Most Important Publications
1 Publication List for Amaury H.M.J. Triaud Listing following SAO/NASA’s ADS paper archive. There are active links to the ADS paper archive in blue. All refereed publication can be accessed by clicking here and all publications, in- cluding conference proceedings, white papers and some proposal abstracts by clicking here. LAST UPDATED ON 2015-07-16: 101 refereed publications, above 2700 citations. H-index = 30. In addition: 4 are submitted or in press, 16 are conference proceedings or white papers. Most important publications WASP-80B HAS A DAYSIDE WITHIN THE T-DWARF RANGE Triaud, Amaury H. M. J., Gillon, Michaël, Ehrenreich, David, Herrero, Enrique, Lendl, Monika, Anderson, David R., Collier Cameron, Andrew, Delrez, Laetitia, Demory, Brice-Olivier, Hellier, Coel, Heng, Kevin, Jehin, Emmanuel, Maxted, Pierre F. L., Pollacco, Don, Queloz, Didier, Ribas, Ignasi, Smalley, Barry, Smith, Alexis M. S., Udry, Stéphane 2015 MNRAS 450 2279 CIRCUMBINARY PLANETS - WHY THEY ARE SO LIKELY TO TRANSIT Martin, D. V. & Triaud, A. H. M. J. 2015 MNRAS 449, 781 PLANETS TRANSITING NON-ECLIPSING BINARIES Martin, D. V. & Triaud, A. H. M. J. 2014 A&A 570, 91 COLOUR-MAGNITUDE DIAGRAMS OF TRANSITING EXOPLANETS I-SYSTEMS WITH PARALLAXES Triaud, A. H. M. J. 2014 MNRAS 439, L61 FAST-EVOLVING WEATHER FOR THE COOLEST OF OUR TWO NEW SUBSTELLAR NEIGHBOURS Gillon, M., Triaud, A. H. M. J., Jehin, E., Delrez, L., Opitom, C., Magain, P., Lendl, M., Queloz, D. 2013 A&A 555, L5 A SEARCH FOR ROCKY PLANETS TRANSITING BROWN DWARFS Triaud, Amaury H. M. J., Gillon, Michael, Selsis, Franck, Winn, Joshua N., Demory, Brice-Olivier, Artigau, Etienne, Laughlin, Gregory P., Seager, Sara, Helling, Christiane, Mayor, Michel, Albert, Loic, Anderson, Richard I., Bolmont, Emeline, Doyon, Rene, Forveille, Thierry, Hagelberg, Janis, Leconte, Jeremy, Lendl, Monika, Littlefair, Stuart, Raymond, Sean, Sahlmann, Johannes (arXiv:1304.7248) WASP-80B: A GAS GIANT TRANSITING A COOL DWARF Triaud, A.