Physical Properties of Kuiper Belt and Centaur Objects: Constraints from the Spitzer Space Telescope
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A Deeper Look at the Colors of the Saturnian Irregular Satellites Arxiv
A deeper look at the colors of the Saturnian irregular satellites Tommy Grav Harvard-Smithsonian Center for Astrophysics, MS51, 60 Garden St., Cambridge, MA02138 and Instiute for Astronomy, University of Hawaii, 2680 Woodlawn Dr., Honolulu, HI86822 [email protected] James Bauer Jet Propulsion Laboratory, California Institute of Technology 4800 Oak Grove Dr., MS183-501, Pasadena, CA91109 [email protected] September 13, 2018 arXiv:astro-ph/0611590v2 8 Mar 2007 Manuscript: 36 pages, with 11 figures and 5 tables. 1 Proposed running head: Colors of Saturnian irregular satellites Corresponding author: Tommy Grav MS51, 60 Garden St. Cambridge, MA02138 USA Phone: (617) 384-7689 Fax: (617) 495-7093 Email: [email protected] 2 Abstract We have performed broadband color photometry of the twelve brightest irregular satellites of Saturn with the goal of understanding their surface composition, as well as their physical relationship. We find that the satellites have a wide variety of different surface colors, from the negative spectral slopes of the two retrograde satellites S IX Phoebe (S0 = −2:5 ± 0:4) and S XXV Mundilfari (S0 = −5:0 ± 1:9) to the fairly red slope of S XXII Ijiraq (S0 = 19:5 ± 0:9). We further find that there exist a correlation between dynamical families and spectral slope, with the prograde clusters, the Gallic and Inuit, showing tight clustering in colors among most of their members. The retrograde objects are dynamically and physically more dispersed, but some internal structure is apparent. Keywords: Irregular satellites; Photometry, Satellites, Surfaces; Saturn, Satellites. 3 1 Introduction The satellites of Saturn can be divided into two distinct groups, the regular and irregular, based on their orbital characteristics. -
Surface Characteristics of Transneptunian Objects and Centaurs from Photometry and Spectroscopy
Barucci et al.: Surface Characteristics of TNOs and Centaurs 647 Surface Characteristics of Transneptunian Objects and Centaurs from Photometry and Spectroscopy M. A. Barucci and A. Doressoundiram Observatoire de Paris D. P. Cruikshank NASA Ames Research Center The external region of the solar system contains a vast population of small icy bodies, be- lieved to be remnants from the accretion of the planets. The transneptunian objects (TNOs) and Centaurs (located between Jupiter and Neptune) are probably made of the most primitive and thermally unprocessed materials of the known solar system. Although the study of these objects has rapidly evolved in the past few years, especially from dynamical and theoretical points of view, studies of the physical and chemical properties of the TNO population are still limited by the faintness of these objects. The basic properties of these objects, including infor- mation on their dimensions and rotation periods, are presented, with emphasis on their diver- sity and the possible characteristics of their surfaces. 1. INTRODUCTION cally with even the largest telescopes. The physical char- acteristics of Centaurs and TNOs are still in a rather early Transneptunian objects (TNOs), also known as Kuiper stage of investigation. Advances in instrumentation on tele- belt objects (KBOs) and Edgeworth-Kuiper belt objects scopes of 6- to 10-m aperture have enabled spectroscopic (EKBOs), are presumed to be remnants of the solar nebula studies of an increasing number of these objects, and signifi- that have survived over the age of the solar system. The cant progress is slowly being made. connection of the short-period comets (P < 200 yr) of low We describe here photometric and spectroscopic studies orbital inclination and the transneptunian population of pri- of TNOs and the emerging results. -
Trans-Neptunian Objects a Brief History, Dynamical Structure, and Characteristics of Its Inhabitants
Trans-Neptunian Objects A Brief history, Dynamical Structure, and Characteristics of its Inhabitants John Stansberry Space Telescope Science Institute IAC Winter School 2016 IAC Winter School 2016 -- Kuiper Belt Overview -- J. Stansberry 1 The Solar System beyond Neptune: History • 1930: Pluto discovered – Photographic survey for Planet X • Directed by Percival Lowell (Lowell Observatory, Flagstaff, Arizona) • Efforts from 1905 – 1929 were fruitless • discovered by Clyde Tombaugh, Feb. 1930 (33 cm refractor) – Survey continued into 1943 • Kuiper, or Edgeworth-Kuiper, Belt? – 1950’s: Pluto represented (K.E.), or had scattered (G.K.) a primordial, population of small bodies – thus KBOs or EKBOs – J. Fernandez (1980, MNRAS 192) did pretty clearly predict something similar to the trans-Neptunian belt of objects – Trans-Neptunian Objects (TNOs), trans-Neptunian region best? – See http://www2.ess.ucla.edu/~jewitt/kb/gerard.html IAC Winter School 2016 -- Kuiper Belt Overview -- J. Stansberry 2 The Solar System beyond Neptune: History • 1978: Pluto’s moon, Charon, discovered – Photographic astrometry survey • 61” (155 cm) reflector • James Christy (Naval Observatory, Flagstaff) – Technologically, discovery was possible decades earlier • Saturation of Pluto images masked the presence of Charon • 1988: Discovery of Pluto’s atmosphere – Stellar occultation • Kuiper airborne observatory (KAO: 90 cm) + 7 sites • Measured atmospheric refractivity vs. height • Spectroscopy suggested N2 would dominate P(z), T(z) • 1992: Pluto’s orbit explained • Outward migration by Neptune results in capture into 3:2 resonance • Pluto’s inclination implies Neptune migrated outward ~5 AU IAC Winter School 2016 -- Kuiper Belt Overview -- J. Stansberry 3 The Solar System beyond Neptune: History • 1992: Discovery of 2nd TNO • 1976 – 92: Multiple dedicated surveys for small (mV > 20) TNOs • Fall 1992: Jewitt and Luu discover 1992 QB1 – Orbit confirmed as ~circular, trans-Neptunian in 1993 • 1993 – 4: 5 more TNOs discovered • c. -
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. -
Markov Chain Monte-Carlo Orbit Computation for Binary Asteroids
SF2A 2013 L. Cambr´esy,F. Martins, E. Nuss and A. Palacios (eds) MARKOV CHAIN MONTE-CARLO ORBIT COMPUTATION FOR BINARY ASTEROIDS Dagmara Oszkiewicz2; 1, Daniel Hestroffer2 and Pedro David2 Abstract. We present a novel method of orbit computation for resolved binary asteroids. The method combines the Thiele, Innes, van den Bos method with a Markov chain Monte Carlo technique (MCMC). The classical Thiele-van den Bos method has been commonly used in multiple applications before, including orbits of binary stars and asteroids; conversely this novel method can be used for the analysis of binary stars, and of other gravitationally bound binaries. The method requires a minimum of three observations (observing times and relative positions - Cartesian or polar) made at the same tangent plane - or close enough for enabling a first approximation. Further, the use of the MCMC technique for statistical inversion yields the whole bundle of possible orbits, including the one that is most probable. In this new method, we make use of the Metropolis-Hastings algorithm to sample the parameters of the Thiele-van den Bos method, that is the orbital period (or equivalently the double areal constant) together with three randomly selected observations from the same tangent plane. The observations are sampled within their observational errors (with an assumed distribution) and the orbital period is the only parameter that has to be tuned during the sampling procedure. We run multiple chains to ensure that the parameter phase space is well sampled and that the solutions have converged. After the sampling is completed we perform convergence diagnostics. The main advantage of the novel approach is that the orbital period does not need to be known in advance and the entire region of possible orbital solutions is sampled resulting in a maximum likelihood solution and the confidence regions. -
Rings Under Close Encounters with the Giant Planets: Chariklo Vs Chiron
Mon. Not. R. Astron. Soc. 000, 1–8 (2017) Printed 15 March 2021 (MN LATEX style file v2.2) Rings under close encounters with the giant planets: Chariklo vs Chiron R. A. N. Araujo1, O. C. Winter1, R. Sfair1 1UNESP - Sao˜ Paulo State University, Grupo de Dinamicaˆ Orbital e Planetologia, CEP 12516-410, Guaratingueta,´ SP, Brazil ABSTRACT In 2014, the discovery of two well-defined rings around the Centaur (10199) Chariklo were announced. This was the first time that such structures were found around a small body. In 2015, it was proposed that the Centaur (2060) Chiron may also have a ring. In a previous study, we analyzed how close encounters with giant planets would affect the rings of Chariklo. The most likely result is the survival of the rings. In the present work, we broaden our analysis to (2060) Chiron. In addition to Chariklo, Chiron is currently the only known Centaur with a presumed ring. By applying the same method as Araujo, Sfair & Winter (2016), we performed numerical integrations of a system composed of 729 clones of Chiron, the Sun, and the giant planets. The number of close encounters that disrupted the ring of Chiron during one half-life of the study period was computed. This number was then compared to the number of close encounters for Chariklo. We found that the probability of Chiron losing its ring due to close encounters with the giant planets is about six times higher than that for Chariklo. Our analysis showed that, unlike Chariklo, Chiron is more likely to remain in an orbit with a relatively low inclination and high eccentricity. -
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). -
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Five New and Three Improved Mutual Orbits of Transneptunian Binaries W.M. Grundya, K.S. Nollb, F. Nimmoc, H.G. Roea, M.W. Buied, S.B. Portera, S.D. Benecchie,f, D.C. Stephensg, H.F. Levisond, and J.A. Stansberryh a. Lowell Observatory, 1400 W. Mars Hill Rd., Flagstaff AZ 86001. b. Space Telescope Science Institute, 3700 San Martin Dr., Baltimore MD 21218. c. Department of Earth and Planetary Sciences, University of California, Santa Cruz CA 95064. d. Southwest Research Institute, 1050 Walnut St. #300, Boulder CO 80302. e. Planetary Science Institute, 1700 E. Fort Lowell, Suite 106, Tucson AZ 85719. f. Carnegie Institution of Washington, Department of Terrestrial Magnetism, 5241 Broad Branch Rd. NW, Washington DC 20015. g. Dept. of Physics and Astronomy, Brigham Young University, N283 ESC Provo UT 84602. h. Steward Observatory, University of Arizona, 933 N. Cherry Ave., Tucson AZ 85721. — Published in 2011: Icarus 213, 678-692. — doi:10.1016/j.icarus.2011.03.012 ABSTRACT We present three improved and five new mutual orbits of transneptunian binary systems (58534) Logos-Zoe, (66652) Borasisi-Pabu, (88611) Teharonhiawako-Sawiskera, (123509) 2000 WK183, (149780) Altjira, 2001 QY297, 2003 QW111, and 2003 QY90 based on Hubble Space Tele- scope and Keck II laser guide star adaptive optics observations. Combining the five new orbit solutions with 17 previously known orbits yields a sample of 22 mutual orbits for which the period P, semimajor axis a, and eccentricity e have been determined. These orbits have mutual periods ranging from 5 to over 800 days, semimajor axes ranging from 1,600 to 37,000 km, ec- centricities ranging from 0 to 0.8, and system masses ranging from 2 × 1017 to 2 × 1022 kg. -
Occultation Newsletter Volume 8, Number 4
Volume 12, Number 1 January 2005 $5.00 North Am./$6.25 Other International Occultation Timing Association, Inc. (IOTA) In this Issue Article Page The Largest Members Of Our Solar System – 2005 . 4 Resources Page What to Send to Whom . 3 Membership and Subscription Information . 3 IOTA Publications. 3 The Offices and Officers of IOTA . .11 IOTA European Section (IOTA/ES) . .11 IOTA on the World Wide Web. Back Cover ON THE COVER: Steve Preston posted a prediction for the occultation of a 10.8-magnitude star in Orion, about 3° from Betelgeuse, by the asteroid (238) Hypatia, which had an expected diameter of 148 km. The predicted path passed over the San Francisco Bay area, and that turned out to be quite accurate, with only a small shift towards the north, enough to leave Richard Nolthenius, observing visually from the coast northwest of Santa Cruz, to have a miss. But farther north, three other observers video recorded the occultation from their homes, and they were fortuitously located to define three well- spaced chords across the asteroid to accurately measure its shape and location relative to the star, as shown in the figure. The dashed lines show the axes of the fitted ellipse, produced by Dave Herald’s WinOccult program. This demonstrates the good results that can be obtained by a few dedicated observers with a relatively faint star; a bright star and/or many observers are not always necessary to obtain solid useful observations. – David Dunham Publication Date for this issue: July 2005 Please note: The date shown on the cover is for subscription purposes only and does not reflect the actual publication date. -
Occultations of HIP and UCAC2 Stars Downto 15M by Large TNO in 2004
Astronomy Letters, 2004, vol. 30. Translated from Pis’ma v Astronomicheskij Zhurnal. Occultations of HIP and UCAC2 stars downto 15m by large TNO in 2004-2014 © 2004 D.V. Denissenko Space Research Institute (IKI), Moscow, Russia Received 27 February 2004 Occultations of stars brighter than 15m by largest TNOs are predicted. Search was performed using the following catalogues: Hipparcos; Tycho2 with coordinates of 2838666 stars taken from UCAC2 (Herald, 2003); UCAC2 (Zacharias et al., 2003) with 16356096 stars between 12.00 and 14.99 mag to the north from -45 declination. Predictions were made for 17 largest numbered transneptunian asteroids, recently discovered 2004 DW and 4 known binary Kuiper Belt objects. 64 events occuring at solar elongation of 30° and more are selected, including exceptionally rare occultation m of 6.5 star by double (66652) 1999 RZ253 on 2007 October 4th. Observations of these events by all available means are extremely important since they can provide unique information about the size of TNOs and improve their orbits dramatically. INTRODUCTION OCCULTATIONS BY TNO Over 800 Transneptunian Objects (TNO) are TNOs are typically at 30-50 AU distances discovered since 1992 with 67 of them being from the Earth corresponding to 0.2"-0.3" numbered and 7 having proper names as of parallax. This means that occultation will February 2004. No reliable measurements only happen somewhere on the Earth if the of their sizes have been obtained so far. geocentric path of the object passes within Angular sizes even of the largest objects are 200-300 mas from the star. Combined with arXiv:astro-ph/0403002 28 Feb 2004 about 0.04"±0.01" (Quaoar) which is at the a very slow angular motion of TNO (0.1-1 limit of Hubble Space Telescope resolution. -
Water Ice in 2060 Chiron and Its Implications for Centaurs and Kuiper Belt Objects
Water Ice in 2060 Chiron and its Implications for Centaurs and Kuiper Belt Objects Jane X. Luu Sterrewacht Leiden Postbus 9513, 2300RA Leiden, The Netherlands David C. Jewitt1 Institute for Astronomy 2680 Woodlawn Drive, Honolulu, HI 96822 and Chad Trujillo1 Institute for Astronomy 2680 Woodlawn Drive, Honolulu, HI 96822 Received ; accepted Submitted to Ap. J. Letters, accepted 31 Jan 2000 1Visiting Astronomer, W. M. Keck Observatory, jointly operated by California Institute of Technology and the University of California. –2– ABSTRACT We report the detection of water ice in the Centaur 2060 Chiron, based on near-infrared spectra (1.0 - 2.5 µm) taken with the 3.8-meter United Kingdom Infrared Telescope (UKIRT) and the 10-meter Keck Telescope. The appearance of this ice is correlated with the recent decline in Chiron’s cometary activity: the decrease in the coma cross-section allows previously hidden solid-state surface features to be seen. We predict that water ice is ubiquitous among Centaurs and Kuiper Belt objects, but its surface coverage varies from object to object, and thus determines its detectability and the occurrence of cometary activity. Subject headings: comets – Kuiper Belt – solar system: formation 1. Introduction The Centaurs are a set of solar system objects whose orbits are confined between those of Jupiter and Neptune. Their planet-crossing orbits imply a short dynamical lifetime (106 107 yr). The current belief is that Centaurs are objects scattered from the Kuiper − Belt that may eventually end up in the inner solar system as short-period comets. The first discovered and brightest known Centaur, 2060 Chiron, is relatively well studied. -
Distant Ekos: 2011 HL103, 2011 KW48, 2012 VR113, 2013 QO95, 2013 QP95 and 4 New Centaur/SDO Discoveries: 2011 JD32, 2012 VS113, 2013 TV158, 2014 OG392
Issue No. 94 August 2014 r✤✜ s ✓✏ DISTANT EKO ❞✐ ✒✑ The Kuiper Belt Electronic Newsletter ✣✢ Edited by: Joel Wm. Parker [email protected] www.boulder.swri.edu/ekonews CONTENTS News & Announcements ................................. 2 Abstracts of 5 Accepted Papers ......................... 3 Newsletter Information .............................. .....7 1 NEWS & ANNOUNCEMENTS There were 5 new TNO discoveries announced since the previous issue of Distant EKOs: 2011 HL103, 2011 KW48, 2012 VR113, 2013 QO95, 2013 QP95 and 4 new Centaur/SDO discoveries: 2011 JD32, 2012 VS113, 2013 TV158, 2014 OG392 Reclassified objects: 2013 LU28 (Centaur → SDO) Deleted/Re-identified objects: 2014 LJ9 = 2013 LU28 Current number of TNOs: 1277 (including Pluto) Current number of Centaurs/SDOs: 401 Current number of Neptune Trojans: 9 Out of a total of 1687 objects: 646 have measurements from only one opposition 629 of those have had no measurements for more than a year 326 of those have arcs shorter than 10 days (for more details, see: http://www.boulder.swri.edu/ekonews/objects/recov_stats.jpg) 2 PAPERS ACCEPTED TO JOURNALS Photometric and Spectroscopic Evidence for a Dense Ring System around Centaur Chariklo R. Duffard1, N. Pinilla-Alonso2, J.L. Ortiz1, A. Alvarez-Candal3, B. Sicardy4, P. Santos-Sanz1, N. Morales1, C. Colazo5, E. Fern´andez-Valenzuela1, and F. Braga-Ribas1 1 Instituto de Astrofisica de Andalucia - CSIC. Glorieta de la Astronom´ıa s/n. Granada. 18008. Spain 2 Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN, 37996-1410, USA 3 Observatorio Nacional de Rio de Janeiro, Rio de Janeiro, Brazil 4 LESIA-Observatoire de Paris, CNRS, UPMC Univ. Paris 6, Univ.