Survival of Amorphous Water Ice on Centaurs
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The Active Centaurs
The Astronomical Journal, 137:4296–4312, 2009 May doi:10.1088/0004-6256/137/5/4296 C 2009. The American Astronomical Society. All rights reserved. Printed in the U.S.A. THE ACTIVE CENTAURS David Jewitt Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA; [email protected] Received 2009 January 5; accepted 2009 February 24; published 2009 April 3 ABSTRACT The Centaurs are recent escapees from the Kuiper Belt that are destined either to meet fiery oblivion in the hot inner regions of the solar system or to be ejected to the interstellar medium by gravitational scattering from the giant planets. Dynamically evolved Centaurs, when captured by Jupiter and close enough to the Sun for near-surface water ice to sublimate, are conventionally labeled as “short-period” (specifically, Jupiter-family) comets. Remarkably, some Centaurs show comet-like activity even when far beyond the orbit of Jupiter, suggesting mass loss driven by a process other than the sublimation of water ice. We observed a sample of 23 Centaurs and found nine to be active, with mass-loss rates measured from several kg s−1 to several tonnes s−1. Considered as a group, we find that the “active Centaurs” in our sample have perihelia smaller than the inactive Centaurs (median 5.9 AU versus 8.7 AU), and smaller than the median perihelion distance computed for all known Centaurs (12.4 AU). This suggests that their activity is thermally driven. We consider several possibilities for the origin of the mass loss from the active Centaurs. Most are too cold for activity at the observed levels to originate via the sublimation of crystalline water ice. -
Visible and Near-Infrared Colors of Transneptunian Objects and Centaurs from the Second ESO Large Program
A&A 493, 283–290 (2009) Astronomy DOI: 10.1051/0004-6361:200810561 & c ESO 2008 Astrophysics Visible and near-infrared colors of Transneptunian objects and Centaurs from the second ESO large program F. E. DeMeo1, S. Fornasier1,2, M. A. Barucci1,D.Perna1,3,4, S. Protopapa5, A. Alvarez-Candal1, A. Delsanti1, A. Doressoundiram1, F. Merlin1, and C. de Bergh1 1 LESIA, Observatoire de Paris, 92195 Meudon Principal Cedex, France e-mail: [email protected] 2 Université de Paris 7 Denis Diderot, Paris, France 3 INAF – Osservatorio Astronomico di Roma, via Frascati 33, 00040 Monte Porzio Catone, Italy 4 Università di Roma Tor Vergata, via della Ricerca Scientifica 1, 00133 Roma, Italy 5 Max Planck Institute for Solar System Research, Lindau, Germany Received 10 July 2008 / Accepted 9 October 2008 ABSTRACT Aims. We investigate color properties and define or check taxonomic classifications of objects observed in our survey. Methods. All observations were performed between October 2006 and September 2007 at the European Southern Observatory 8 m Very Large Telescope, UT1 and UT2 at the Paranal Observatory in Chile. For visible photometry, we used the FORS1 instrument, and for near-infrared, ISAAC. Taxonomic classifications from the Barucci system were assigned using G-mode analysis. Results. We present photometric observations of 23 TNOs and Centaurs, nine of which have never been previously observed. Eighteen of these objects were assigned taxonomic classifications: six BB, four BR, two RR, and six that are given two or more categories due to insufficient data. Three objects that had been previously observed and classified, changed classes most likely due to surface vari- ation: 26375 (1999 DE9), 28978 (Ixion), and 32532 (Thereus). -
Arxiv:Astro-Ph/0605606 V1 23 May 2006 Et Fsaesuis Otws Eerhisiue Ste
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CERN Document Server Discovery of a Binary Centaur Keith S. Noll Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 [email protected] Harold F. Levison Dept. of Space Studies, Southwest Research Institute, Ste. 400, 1050 Walnut St., Boulder, CO 80302 [email protected] Will M. Grundy Lowell Observatory, 1400 W. Mars Hill Rd., Flagstaff, AZ 86001 [email protected] Denise C. Stephens Johns Hopkins University, Dept. Physics and Astronomy, Baltimore, MD 21218 [email protected] ABSTRACT We have identified a binary companion to (42355) 2002 CR46 in our ongoing deep survey using the Hubble Space Telescope’s High Resolution Camera. It is the first com- panion to be found around an object in a non-resonant orbit that crosses the orbits of arXiv:astro-ph/0605606 v1 23 May 2006 giant planets. Objects in orbits of this kind, the Centaurs, have experienced repeated strong scattering with one or more giant planets and therefore the survival of binaries in this transient population has been in question. Monte Carlo simulations suggest, however, that binaries in (42355) 2002 CR46-like heliocentric orbits have a high proba- bility of survival for reasonable estimates of the binary’s still-unknown system mass and separation. Because Centaurs are thought to be precursors to short period comets, the question of the existence of binary comets naturally arises; none has yet been defini- tively identified. The discovery of one binary in a sample of eight observed by HST suggests that binaries in this population may not be uncommon. -
Colours of Minor Bodies in the Outer Solar System II - a Statistical Analysis, Revisited
Astronomy & Astrophysics manuscript no. MBOSS2 c ESO 2012 April 26, 2012 Colours of Minor Bodies in the Outer Solar System II - A Statistical Analysis, Revisited O. R. Hainaut1, H. Boehnhardt2, and S. Protopapa3 1 European Southern Observatory (ESO), Karl Schwarzschild Straße, 85 748 Garching bei M¨unchen, Germany e-mail: [email protected] 2 Max-Planck-Institut f¨ur Sonnensystemforschung, Max-Planck Straße 2, 37 191 Katlenburg- Lindau, Germany 3 Department of Astronomy, University of Maryland, College Park, MD 20 742-2421, USA Received —; accepted — ABSTRACT We present an update of the visible and near-infrared colour database of Minor Bodies in the outer Solar System (MBOSSes), now including over 2000 measurement epochs of 555 objects, extracted from 100 articles. The list is fairly complete as of December 2011. The database is now large enough that dataset with a high dispersion can be safely identified and rejected from the analysis. The method used is safe for individual outliers. Most of the rejected papers were from the early days of MBOSS photometry. The individual measurements were combined so not to include possible rotational artefacts. The spectral gradient over the visible range is derived from the colours, as well as the R absolute magnitude M(1, 1). The average colours, absolute magnitude, spectral gradient are listed for each object, as well as their physico-dynamical classes using a classification adapted from Gladman et al., 2008. Colour-colour diagrams, histograms and various other plots are presented to illustrate and in- vestigate class characteristics and trends with other parameters, whose significance are evaluated using standard statistical tests. -
Physical Properties of Centaur (54598) Bienor from Photometry 3
MNRAS 000, 1–13 (2015) Preprint 15 May 2018 Compiled using MNRAS LATEX style file v3.0 Physical properties of centaur (54598) Bienor from photometry E. Fern´andez-Valenzuela,1⋆ J. L. Ortiz1, R. Duffard1, N. Morales1, P. Santos-Sanz1 1Instituto de Astrof´ısica de Andaluc´ıa, CSIC, Glorieta de la Astronom´ıa s/n, Granada 18008, Spain Accepted XXX. Received YYY; in original form ZZZ ABSTRACT We present time series photometry of Bienor in four observation campaigns from 2013 to 2016 and compare them with previous observations in the literature dating back to 2000. The results show a remarkable decline in the amplitude of the rotational light curve and in the absolute magnitude. This suggests that the angle between the rotation axis and the line of sight has changed noticeably during the last 16 years as Bienor orbits the Sun. From the light curve amplitude data we are able to determine ◦ ◦ the orientation of the rotation axis of Bienor (βp = 50 ± 3 , λp = 35 ± 8 ). We are also able to constrain the b/a axial ratio of a triaxial Jacobi ellipsoidal body (with semi-axis a>b>c). The best fit is for b/a = 0.45 ± 0.05, which corresponds to a +47 −3 density value of 594−35 kg m under the usual assumption of hydrostatic equilibrium and given that Bienor’s rotational period is 9.17 h. However, the absolute magnitude of Bienor at several epochs is not well reproduced. We tested several explanations such as relaxing the hydrostatic equilibrium constraint, a large North-South asymmetry in the surface albedo of Bienor or even a ring system. -
Appendix 1 1311 Discoverers in Alphabetical Order
Appendix 1 1311 Discoverers in Alphabetical Order Abe, H. 28 (8) 1993-1999 Bernstein, G. 1 1998 Abe, M. 1 (1) 1994 Bettelheim, E. 1 (1) 2000 Abraham, M. 3 (3) 1999 Bickel, W. 443 1995-2010 Aikman, G. C. L. 4 1994-1998 Biggs, J. 1 2001 Akiyama, M. 16 (10) 1989-1999 Bigourdan, G. 1 1894 Albitskij, V. A. 10 1923-1925 Billings, G. W. 6 1999 Aldering, G. 4 1982 Binzel, R. P. 3 1987-1990 Alikoski, H. 13 1938-1953 Birkle, K. 8 (8) 1989-1993 Allen, E. J. 1 2004 Birtwhistle, P. 56 2003-2009 Allen, L. 2 2004 Blasco, M. 5 (1) 1996-2000 Alu, J. 24 (13) 1987-1993 Block, A. 1 2000 Amburgey, L. L. 2 1997-2000 Boattini, A. 237 (224) 1977-2006 Andrews, A. D. 1 1965 Boehnhardt, H. 1 (1) 1993 Antal, M. 17 1971-1988 Boeker, A. 1 (1) 2002 Antolini, P. 4 (3) 1994-1996 Boeuf, M. 12 1998-2000 Antonini, P. 35 1997-1999 Boffin, H. M. J. 10 (2) 1999-2001 Aoki, M. 2 1996-1997 Bohrmann, A. 9 1936-1938 Apitzsch, R. 43 2004-2009 Boles, T. 1 2002 Arai, M. 45 (45) 1988-1991 Bonomi, R. 1 (1) 1995 Araki, H. 2 (2) 1994 Borgman, D. 1 (1) 2004 Arend, S. 51 1929-1961 B¨orngen, F. 535 (231) 1961-1995 Armstrong, C. 1 (1) 1997 Borrelly, A. 19 1866-1894 Armstrong, M. 2 (1) 1997-1998 Bourban, G. 1 (1) 2005 Asami, A. 7 1997-1999 Bourgeois, P. 1 1929 Asher, D. -
Photometry of Active Centaurs: Colors of Dormant Active Centaur Nuclei
The Astronomical Journal, 157:225 (11pp), 2019 June https://doi.org/10.3847/1538-3881/ab1b22 © 2019. The American Astronomical Society. All rights reserved. Photometry of Active Centaurs: Colors of Dormant Active Centaur Nuclei Ian Wong1,4 , Aakash Mishra2, and Michael E. Brown3 1 Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; [email protected] 2 Davis Senior High School, Davis, CA 95616, USA 3 Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA Received 2019 March 11; revised 2019 April 17; accepted 2019 April 18; published 2019 May 13 Abstract We present multiband photometric observations of nine Centaurs. Five of the targets are known active Centaurs (167P/CINEOS, 174P/Echeclus, P/2008 CL94, P/2011 S1, and C/2012 Q1), and the other four are inactive Centaurs belonging to the redder of the two known color subpopulations (83982 Crantor, 121725 Aphidas, 250112 2002 KY14, and 281371 2008 FC76). We measure the optical colors of eight targets and carry out a search for cometary activity. In addition to the four inactive Centaurs, three of the five active Centaurs showed no signs of activity at the time of observation, yielding the first published color measurements of the bare nuclei of 167P and P/2008 CL94 without possible coma contamination. Activity was detected on P/2011 S1 and C/2012 Q1, yielding relatively high estimated mass loss rates of 140±20 and 250±40kg s−1, respectively. The colors of the dormant nuclei are consistent with the previously published colors, indicating that any effect of non-geometric scattering from Centaur dust or blanketing debris on the measured colors is minimal. -
Transneptunian Object Taxonomy 181
Fulchignoni et al.: Transneptunian Object Taxonomy 181 Transneptunian Object Taxonomy Marcello Fulchignoni LESIA, Observatoire de Paris Irina Belskaya Kharkiv National University Maria Antonietta Barucci LESIA, Observatoire de Paris Maria Cristina De Sanctis IASF-INAF, Rome Alain Doressoundiram LESIA, Observatoire de Paris A taxonomic scheme based on multivariate statistics is proposed to distinguish groups of TNOs having the same behavior concerning their BVRIJ colors. As in the case of asteroids, the broadband spectrophotometry provides a first hint about the bulk compositional properties of the TNOs’ surfaces. Principal components (PC) analysis shows that most of the TNOs’ color variability can be accounted for by a single component (i.e., a linear combination of the col- ors): All the studied objects are distributed along a quasicontinuous trend spanning from “gray” (neutral color with respect to those of the Sun) to very “red” (showing a spectacular increase in the reflectance of the I and J bands). A finer structure is superimposed to this trend and four homogeneous “compositional” classes emerge clearly, and independently from the PC analy- sis, if the TNO sample is analyzed with a grouping technique (the G-mode statistics). The first class (designed as BB) contains the objects that are neutral in color with respect to the Sun, while the RR class contains the very red ones. Two intermediate classes are separated by the G mode: the BR and the IR, which are clearly distinguished by the reflectance relative increases in the R and I bands. Some characteristics of the classes are deduced that extend to all the objects of a given class the properties that are common to those members of the class for which more detailed data are available (observed activity, full spectra, albedo). -
Characterization of Asteroids and Tnos Authors: T
Small Bodies Near and Far (SBNAF): Characterization of asteroids and TNOs Authors: T. G. Müller1, A. Marciniak2, Cs. Kiss3, R. Duffard4, V. Alí-Lagoa1, P. Bartczak2, M. Butkiewicz- Bąk2, G. Dudziński2, E. Fernández-Valenzuela4, G. Marton3, N. Morales4, J.-L. Ortiz4, D. Oszkiewicz2, T. Santana-Ros2, P. Santos-Sanz4, R. Szakáts3, A. Takácsné Farkas3, E. Varga-Verebélyi3 1: MPI für Extraterrestrische Physik (MPE), Garching, Germany. 2: Astronomical Observatory Institute (UAM), Poznań, Poland. 3: Konkoly Observatory, Budapest, Hungary. 4: Instituto de Astrofísica de Andalucía (IAA) - CSIC, Granada, Spain. Abstract: We present results from an EU Horizon2020-funded benchmark study (2016-2019) that addresses critical points in reconstructing physical and thermal prop- erties of near-Earth, main-belt, and trans-Neptunian objects. The combination of the visual and thermal data from the ground and from astrophysics space missions is key to improving the scientific understanding of these objects. The development of new tools is crucial for the interpretation of much larger data sets, but also for the operations and scientific exploitation of interplanetary missions. We combine different methods and techniques to get full information on selected bodies: lightcurve inversion, stellar occultations, thermophysical modeling, radiometric methods, radar ranging and adaptive optics imaging. The applications to objects with ground- truth information from interplanetary missions Hayabusa, NEAR-Shoemaker, Rosetta, and DAWN allow us to advance the techniques beyond the current state-of-the- art and to assess the limitations of each method. We present our recently developed tools, services, products, deliverables, and list important SBNAF publications. Results I: Tools & Services • ISAM service (http://isam.astro.amu.edu.pl/) contains shape models for more than 900 asteroids. -
A Spectroscopic Analysis of Jupiter-Coupled Object (52872) Okyrhoe, and Tnos (90482) Orcus and (73480) 2002 PN34*
A&A 521, A35 (2010) Astronomy DOI: 10.1051/0004-6361/201014042 & c ESO 2010 ! Astrophysics AspectroscopicanalysisofJupiter-coupledobject(52872) ! Okyrhoe, and TNOs (90482) Orcus and (73480) 2002 PN34 F. E. DeMeo1,M.A.Barucci1,F.Merlin2,A.Guilbert-Lepoutre3 ,A.Alvarez-Candal4, A. Delsanti5,S.Fornasier1,6,andC.deBergh1 1 LESIA, Observatoire de Paris, 5 place Jules Janssen, 92195 Meudon Principal Cedex, France e-mail: [email protected] 2 University of Maryland, College Park, MD 20742, USA 3 UCLA Department of Earth and Space Sciences, 595 Charles E. Young Drive E, Los Angeles, CA 90095, USA 4 ESO, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago 19, Chile 5 Laboratoire d’Astrophysique de Marseille, Université de Provence, CNRS, 38 rue Frédéric Joliot-Curie, 13388 Marseille Cedex 13, France 6 Université de Paris 7 Denis Diderot, Paris, France Received 11 January 2010 / Accepted 19 May 2010 ABSTRACT Aims. We present new visible and near-infrared photometric measurements and near-infrared spectroscopic measurements for three outer solar system small bodies, the Jupiter-coupled object (52872) Okyrhoe and the TNOs (90482) Orcus and (73480) 2002 PN34. Methods. We analyzed their surface compositions by modeling their spectra in the visible and near-infrared wavelength ranges. We then compared this new data with previous measurements of Okyrhoe and Orcus to search for heterogeneity on their surfaces. All observations were performed at the European Southern Observatory 8 m Very Large Telescope, UT1 and UT4 at the Paranal Observatory in Chile. Results. We find varying amounts of H2Oiceamongthesebodies,Okyrhoeshowsnotraceofitinourspectrum,73480hassmall amounts, and Orcus has large quantities. -
The Reddest Transneptunian Objects
EPSC Abstracts Vol. 7 EPSC2012-155 2012 European Planetary Science Congress 2012 EEuropeaPn PlanetarSy Science CCongress c Author(s) 2012 The reddest transneptunian objects M.A. Barucci (1), F. Merlin (1), D. Perna (1), S. Fornasier (1) and C. de Bergh (1) (1) LESIA-Observatoire de Paris, CNRS, Univ. Pierre et Marie Curie, Univ. Paris Denis Diderot, 92195 Meudon Principal Cedex, France ([email protected] /Fax +33. 145077144) Abstract together with the fact that all colors are also randomly distributed, strongly argue in favor of the We analysed the reddest objects of the important mixing that occurred during the solar transneptunian and centaur populations, following system formation [3, 4]. the taxonomical class RR. The RR class of objects among the studied objects contains more than ¼ of the whole populations, including Centaurs, detached, classical, plutinos and scattered objects, and contains objects with all classes of ice content with a slight majority of sure ice content. 1. Introduction The last 20 years of studies of transneptunian objects changed completely our view on the formation and evolution of the Solar System. Fig 1: The lower left panel shows the distribution of Nevertheless their physical properties remain still the four TNO taxonomic groups (whose average unexplained. Barucci et al. [1] characterized the photometric colors are represented in the upper left panel physical properties and the surface composition of as reflectance values normalized to the Sun in the V-band) within each dynamical class. The right panel shows the these objects, obtaining high quality data for about 40 distribution of the taxonomical groups, with respect to the objects using the most powerful telescopes and orbital inclination relative to the ecliptic plane, for the instruments at VLT-ESO. -
Physical Properties of Transneptunian Objects 879
Cruikshank et al.: Physical Properties of Transneptunian Objects 879 Physical Properties of Transneptunian Objects D. P. Cruikshank NASA Ames Research Center M. A. Barucci Observatoire de Paris, Meudon J. P. Emery SETI Institute and NASA Ames Research Center Y. R. Fernández University of Central Florida W. M. Grundy Lowell Observatory K. S. Noll Space Telescope Science Institute J. A. Stansberry University of Arizona In 1992, the first body beyond Neptune since the discovery of Pluto in 1930 was found. Since then, nearly a thousand solid bodies, including some of planetary size, have been dis- covered in the outer solar system, largely beyond Neptune. Observational studies of an expanding number of these objects with space- and groundbased telescopes are revealing an unexpected diversity in their physical characteristics. Their colors range from neutral to very red, revealing diversity in their intrinsic surface compositions and/or different degrees of processing that they have endured. While some show no diagnostic spectral bands, others have surface deposits of ices of H2O, CH4, and N2, sharing these properties with Pluto and Triton. Thermal emission spectra of some suggest the presence of silicate minerals. Measurements of thermal emission allow determinations of the dimensions and surface albedos of the larger (diameter > ~75 km) members of the known population; geometric albedos range widely from 2.5% to >60%. Some 22 transneptunian objects (including Pluto) are multiple systems. Pluto has three satellites, while 21 other bodies, representing about 11% of the sample investigated, are binary systems. In one binary system where both the mass and radius are reliably known, the mean density of the pri- mary is ~500 kg/m3, comparable to some comets [e.g., Comet 1P/Halley (Keller et al., 2004)].