Dwarf Planet Ceres: Ellipsoid Dimensions and Rotational Pole from Keck and VLT Adaptive Optics Images Q ⇑ J.D
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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. -
Phobos, Deimos: Formation and Evolution Alex Soumbatov-Gur
Phobos, Deimos: Formation and Evolution Alex Soumbatov-Gur To cite this version: Alex Soumbatov-Gur. Phobos, Deimos: Formation and Evolution. [Research Report] Karpov institute of physical chemistry. 2019. hal-02147461 HAL Id: hal-02147461 https://hal.archives-ouvertes.fr/hal-02147461 Submitted on 4 Jun 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Phobos, Deimos: Formation and Evolution Alex Soumbatov-Gur The moons are confirmed to be ejected parts of Mars’ crust. After explosive throwing out as cone-like rocks they plastically evolved with density decays and materials transformations. Their expansion evolutions were accompanied by global ruptures and small scale rock ejections with concurrent crater formations. The scenario reconciles orbital and physical parameters of the moons. It coherently explains dozens of their properties including spectra, appearances, size differences, crater locations, fracture symmetries, orbits, evolution trends, geologic activity, Phobos’ grooves, mechanism of their origin, etc. The ejective approach is also discussed in the context of observational data on near-Earth asteroids, main belt asteroids Steins, Vesta, and Mars. The approach incorporates known fission mechanism of formation of miniature asteroids, logically accounts for its outliers, and naturally explains formations of small celestial bodies of various sizes. -
Exploration of the Kuiper Belt by High-Precision Photometric Stellar Occultations: First Results F
Exploration of the Kuiper Belt by High-Precision Photometric Stellar Occultations: First Results F. Roques, A. Doressoundiram, V. Dhillon, T. Marsh, S. Bickerton, J. J. Kavelaars, M. Moncuquet, M. Auvergne, I. Belskaya, M. Chevreton, et al. To cite this version: F. Roques, A. Doressoundiram, V. Dhillon, T. Marsh, S. Bickerton, et al.. Exploration of the Kuiper Belt by High-Precision Photometric Stellar Occultations: First Results. Astronomical Journal, Amer- ican Astronomical Society, 2006, 132, pp.819-822. 10.1086/505623. hal-00640050 HAL Id: hal-00640050 https://hal.archives-ouvertes.fr/hal-00640050 Submitted on 10 Nov 2011 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. The Astronomical Journal, 132:819Y822, 2006 August # 2006. The American Astronomical Society. All rights reserved. Printed in U.S.A. EXPLORATION OF THE KUIPER BELT BY HIGH-PRECISION PHOTOMETRIC STELLAR OCCULTATIONS: FIRST RESULTS F. Roques,1,2 A. Doressoundiram,1 V. Dhillon,3 T. Marsh,4 S. Bickerton,5,6 J. J. Kavelaars,5 M. Moncuquet,1 M. Auvergne,1 I. Belskaya,7 M. Chevreton,1 F. Colas,1 A. Fernandez,1 A. Fitzsimmons,8 J. Lecacheux,1 O. Mousis,9 S. -
March 21–25, 2016
FORTY-SEVENTH LUNAR AND PLANETARY SCIENCE CONFERENCE PROGRAM OF TECHNICAL SESSIONS MARCH 21–25, 2016 The Woodlands Waterway Marriott Hotel and Convention Center The Woodlands, Texas INSTITUTIONAL SUPPORT Universities Space Research Association Lunar and Planetary Institute National Aeronautics and Space Administration CONFERENCE CO-CHAIRS Stephen Mackwell, Lunar and Planetary Institute Eileen Stansbery, NASA Johnson Space Center PROGRAM COMMITTEE CHAIRS David Draper, NASA Johnson Space Center Walter Kiefer, Lunar and Planetary Institute PROGRAM COMMITTEE P. Doug Archer, NASA Johnson Space Center Nicolas LeCorvec, Lunar and Planetary Institute Katherine Bermingham, University of Maryland Yo Matsubara, Smithsonian Institute Janice Bishop, SETI and NASA Ames Research Center Francis McCubbin, NASA Johnson Space Center Jeremy Boyce, University of California, Los Angeles Andrew Needham, Carnegie Institution of Washington Lisa Danielson, NASA Johnson Space Center Lan-Anh Nguyen, NASA Johnson Space Center Deepak Dhingra, University of Idaho Paul Niles, NASA Johnson Space Center Stephen Elardo, Carnegie Institution of Washington Dorothy Oehler, NASA Johnson Space Center Marc Fries, NASA Johnson Space Center D. Alex Patthoff, Jet Propulsion Laboratory Cyrena Goodrich, Lunar and Planetary Institute Elizabeth Rampe, Aerodyne Industries, Jacobs JETS at John Gruener, NASA Johnson Space Center NASA Johnson Space Center Justin Hagerty, U.S. Geological Survey Carol Raymond, Jet Propulsion Laboratory Lindsay Hays, Jet Propulsion Laboratory Paul Schenk, -
Abstracts of the 50Th DDA Meeting (Boulder, CO)
Abstracts of the 50th DDA Meeting (Boulder, CO) American Astronomical Society June, 2019 100 — Dynamics on Asteroids break-up event around a Lagrange point. 100.01 — Simulations of a Synthetic Eurybates 100.02 — High-Fidelity Testing of Binary Asteroid Collisional Family Formation with Applications to 1999 KW4 Timothy Holt1; David Nesvorny2; Jonathan Horner1; Alex B. Davis1; Daniel Scheeres1 Rachel King1; Brad Carter1; Leigh Brookshaw1 1 Aerospace Engineering Sciences, University of Colorado Boulder 1 Centre for Astrophysics, University of Southern Queensland (Boulder, Colorado, United States) (Longmont, Colorado, United States) 2 Southwest Research Institute (Boulder, Connecticut, United The commonly accepted formation process for asym- States) metric binary asteroids is the spin up and eventual fission of rubble pile asteroids as proposed by Walsh, Of the six recognized collisional families in the Jo- Richardson and Michel (Walsh et al., Nature 2008) vian Trojan swarms, the Eurybates family is the and Scheeres (Scheeres, Icarus 2007). In this theory largest, with over 200 recognized members. Located a rubble pile asteroid is spun up by YORP until it around the Jovian L4 Lagrange point, librations of reaches a critical spin rate and experiences a mass the members make this family an interesting study shedding event forming a close, low-eccentricity in orbital dynamics. The Jovian Trojans are thought satellite. Further work by Jacobson and Scheeres to have been captured during an early period of in- used a planar, two-ellipsoid model to analyze the stability in the Solar system. The parent body of the evolutionary pathways of such a formation event family, 3548 Eurybates is one of the targets for the from the moment the bodies initially fission (Jacob- LUCY spacecraft, and our work will provide a dy- son and Scheeres, Icarus 2011). -
Tilting Saturn II. Numerical Model
Tilting Saturn II. Numerical Model Douglas P. Hamilton Astronomy Department, University of Maryland College Park, MD 20742 [email protected] and William R. Ward Southwest Research Institute Boulder, CO 80303 [email protected] Received ; accepted Submitted to the Astronomical Journal, December 2003 Resubmitted to the Astronomical Journal, June 2004 – 2 – ABSTRACT We argue that the gas giants Jupiter and Saturn were both formed with their rotation axes nearly perpendicular to their orbital planes, and that the large cur- rent tilt of the ringed planet was acquired in a post formation event. We identify the responsible mechanism as trapping into a secular spin-orbit resonance which couples the angular momentum of Saturn’s rotation to that of Neptune’s orbit. Strong support for this model comes from i) a near match between the precession frequencies of Saturn’s pole and the orbital pole of Neptune and ii) the current directions that these poles point in space. We show, with direct numerical inte- grations, that trapping into the spin-orbit resonance and the associated growth in Saturn’s obliquity is not disrupted by other planetary perturbations. Subject headings: planets and satellites: individual (Saturn, Neptune) — Solar System: formation — Solar System: general 1. INTRODUCTION The formation of the Solar System is thought to have begun with a cold interstellar gas cloud that collapsed under its own self-gravity. Angular momentum was preserved during the process so that the young Sun was initially surrounded by the Solar Nebula, a spinning disk of gas and dust. From this disk, planets formed in a sequence of stages whose details are still not fully understood. -
Appulses of Jupiter and Saturn
IN ORIGINAL FORM PUBLISHED IN: arXiv:(side label) [physics.pop-ph] Sternzeit 46, No. 1+2 / 2021 (ISSN: 0721-8168) Date: 6th May 2021 Appulses of Jupiter and Saturn Joachim Gripp, Emil Khalisi Sternzeit e.V., Kiel and Heidelberg, Germany e-mail: gripp or khalisi ...[at]sternzeit-online[dot]de Abstract. The latest conjunction of Jupiter and Saturn occurred at an optical distance of 6 arc minutes on 21 December 2020. We re-analysed all encounters of these two planets between -1000 and +3000 CE, as the extraordinary ones (< 10′) take place near the line of nodes every 400 years. An occultation of their discs did not and will not happen within the historical time span of ±5,000 years around now. When viewed from Neptune though, there will be an occultation in 2046. Keywords: Jupiter-Saturn conjunction, Appulse, Trigon, Occultation. Introduction reason is due to Earth’s orbit: while Jupiter and Saturn are locked in a 5:2-mean motion resonance, the Earth does not The slowest naked-eye planets Jupiter and Saturn made an join in. For very long periods there could be some period- impressive encounter in December 2020. Their approaches icity, however, secular effects destroy a cycle, e.g. rotation have been termed “Great Conjunctions” in former times of the apsides and changes in eccentricity such that we are and they happen regularly every ≈20 years. Before the left with some kind of “semi-periodicity”. discovery of the outer ice giants these classical planets rendered the longest known cycle. The separation at the instant of conjunction varies up to 1 degree of arc, but the Close Encounters latest meeting was particularly tight since the planets stood Most pass-bys of Jupiter and Saturn are not very spectac- closer than at any other occasion for as long as 400 years. -
Tilting Ice Giants with a Spin–Orbit Resonance
The Astrophysical Journal, 888:60 (12pp), 2020 January 10 https://doi.org/10.3847/1538-4357/ab5d35 © 2020. The American Astronomical Society. All rights reserved. Tilting Ice Giants with a Spin–Orbit Resonance Zeeve Rogoszinski and Douglas P. Hamilton Astronomy Department, University of Maryland, College Park, MD 20742, USA; [email protected], [email protected] Received 2019 August 28; revised 2019 November 20; accepted 2019 November 26; published 2020 January 8 Abstract Giant collisions can account for Uranus’s and Neptune’s large obliquities, yet generating two planets with widely different tilts and strikingly similar spin rates is a low-probability event. Trapping into a secular spin–orbit resonance, a coupling between spin and orbit precession frequencies, is a promising alternative, as it can tilt the planet without altering its spin period. We show with numerical integrations that if Uranus harbored a massive circumplanetary disk at least three times the mass of its satellite system while it was accreting its gaseous atmosphere, then its spin precession rate would increase enough to resonate with its own orbit, potentially driving the planet’s obliquity to 70°.Wefind that the presence of a massive disk moves the Laplace radius significantly outward from its classical value, resulting in more of the disk contributing to the planet’s pole precession. Although we can generate tilts greater than 70°only rarely and cannot drive tilts beyond 90°, a subsequent collision with an object about 0.5 M⊕ could tilt Uranus from 70°to 98°. Minimizing the masses and number of giant impactors from two or more to just one increases the likelihood of producing Uranus’s spin states by about an order of magnitude. -
ASTEROID OCCULTATIONOCCULTATION OBSERVINGOBSERVING (And Recording) ~ a Basic Introduction ~
ASTEROIDASTEROID OCCULTATIONOCCULTATION OBSERVINGOBSERVING (and recording) ~ A basic introduction ~ Most amateur astronomers look forward to observing eclipses – a nice lunar eclipse, and the all-too- rare solar variety. Some travel for hundreds of miles to “catch the shadow”. ...But did you know there are potential eclipses to observe nearly every clear night? There are ---- Asteroid Occultations. What's an asteroid occultation? Assuming you know what an asteroid is.... There are now just over 1 MILLION asteroids that have published orbits. Over 500,000 of them have orbits that are established well enough that they have been “numbered” (in general, the lower the number, the more refined the orbit). There are also billions of stars visible thru a telescope in the night sky. It's only inevitable that at times the alignment will be just right for these chunks of rock in space to pass in front of the absolute pinpoint light from stars. If you are in just the right place on Earth, the asteroid will “eclipse” the star, blocking out its light for anywhere from a fraction of a second, to up to 10's of seconds. As the star is essentially infinitely far away – as compared to the distance to the asteroid – the “shadow” the asteroid casts on Earth is basically the size of the asteroid. This shadow moves across the surface of the Earth in a narrow band (the width of which is the diameter of the asteroid), often crossing thousands of miles of the Earth's surface. If you are located somewhere in this narrow band, and it's clear out, you can see the star “blink out”, and then back - an asteroid occultation. -
Simulation of Attitude and Orbital Disturbances Acting on ASPECT Satellite in the Vicinity of the Binary Asteroid Didymos
Simulation of attitude and orbital disturbances acting on ASPECT satellite in the vicinity of the binary asteroid Didymos Erick Flores García Space Engineering, masters level (120 credits) 2017 Luleå University of Technology Department of Computer Science, Electrical and Space Engineering Simulation of attitude and orbital disturbances acting on ASPECT satellite in the vicinity of the binary asteroid Didymos Erick Flores Garcia School of Electrical Engineering Thesis submitted for examination for the degree of Master of Science in Technology. Espoo December 6, 2016 Thesis supervisors: Prof. Jaan Praks Dr. Leonard Felicetti Aalto University Luleå University of Technology School of Electrical Engineering Thesis advisors: M.Sc. Tuomas Tikka M.Sc. Nemanja Jovanović aalto university abstract of the school of electrical engineering master’s thesis Author: Erick Flores Garcia Title: Simulation of attitude and orbital disturbances acting on ASPECT satellite in the vicinity of the binary asteroid Didymos Date: December 6, 2016 Language: English Number of pages: 9+84 Department of Radio Science and Engineering Professorship: Automation Technology Supervisor: Prof. Jaan Praks Advisors: M.Sc. Tuomas Tikka, M.Sc. Nemanja JovanoviÊ Asteroid missions are gaining interest from the scientific community and many new missions are planned. The Didymos binary asteroid is a Near-Earth Object and the target of the Asteroid Impact and Deflection Assessment (AIDA). This joint mission, developed by NASA and ESA, brings the possibility to build one of the first CubeSats for deep space missions: the ASPECT satellite. Navigation systems of a deep space satellite differ greatly from the common planetary missions. Orbital environment close to an asteroid requires a case-by-case analysis. -
Near-Infrared Mapping and Physical Properties of the Dwarf-Planet Ceres
A&A 478, 235–244 (2008) Astronomy DOI: 10.1051/0004-6361:20078166 & c ESO 2008 Astrophysics Near-infrared mapping and physical properties of the dwarf-planet Ceres B. Carry1,2,C.Dumas1,3,, M. Fulchignoni2, W. J. Merline4, J. Berthier5, D. Hestroffer5,T.Fusco6,andP.Tamblyn4 1 ESO, Alonso de Córdova 3107, Vitacura, Santiago de Chile, Chile e-mail: [email protected] 2 LESIA, Observatoire de Paris-Meudon, 5 place Jules Janssen, 92190 Meudon Cedex, France 3 NASA/JPL, MS 183-501, 4800 Oak Grove Drive, Pasadena, CA 91109-8099, USA 4 SwRI, 1050 Walnut St. # 300, Boulder, CO 80302, USA 5 IMCCE, Observatoire de Paris, CNRS, 77 Av. Denfert Rochereau, 75014 Paris, France 6 ONERA, BP 72, 923222 Châtillon Cedex, France Received 26 June 2007 / Accepted 6 November 2007 ABSTRACT Aims. We study the physical characteristics (shape, dimensions, spin axis direction, albedo maps, mineralogy) of the dwarf-planet Ceres based on high angular-resolution near-infrared observations. Methods. We analyze adaptive optics J/H/K imaging observations of Ceres performed at Keck II Observatory in September 2002 with an equivalent spatial resolution of ∼50 km. The spectral behavior of the main geological features present on Ceres is compared with laboratory samples. Results. Ceres’ shape can be described by an oblate spheroid (a = b = 479.7 ± 2.3km,c = 444.4 ± 2.1 km) with EQJ2000.0 spin α = ◦ ± ◦ δ =+ ◦ ± ◦ . +0.000 10 vector coordinates 0 288 5 and 0 66 5 . Ceres sidereal period is measured to be 9 074 10−0.000 14 h. We image surface features with diameters in the 50–180 km range and an albedo contrast of ∼6% with respect to the average Ceres albedo. -
Precise Astrometry and Diameters of Asteroids from Occultations – a Data-Set of Observations and Their Interpretation
MNRAS 000,1–22 (2020) Preprint 14 October 2020 Compiled using MNRAS LATEX style file v3.0 Precise astrometry and diameters of asteroids from occultations – a data-set of observations and their interpretation David Herald 1¢, David Gault2, Robert Anderson3, David Dunham4, Eric Frappa5, Tsutomu Hayamizu6, Steve Kerr7, Kazuhisa Miyashita8, John Moore9, Hristo Pavlov10, Steve Preston11, John Talbot12, Brad Timerson (deceased)13 1Trans Tasman Occultation Alliance, [email protected] 2Trans Tasman Occultation Alliance, [email protected] 3International Occultation Timing Association, [email protected] 4International Occultation Timing Association, [email protected] 5Euraster, [email protected] 6Japanese Occultation Information Network, [email protected] 7Trans Tasman Occultation Alliance, [email protected] 8Japanese Occultation Information Network, [email protected] 9International Occultation Timing Association, [email protected] 10International Occultation Timing Association – European Section, [email protected] 11International Occultation Timing Association, [email protected] 12Trans Tasman Occultation Alliance, [email protected] 13International Occultation Timing Association, deceased Accepted XXX. Received YYY; in original form ZZZ ABSTRACT Occultations of stars by asteroids have been observed since 1961, increasing from a very small number to now over 500 annually. We have created and regularly maintain a growing data-set of more than 5,000 observed asteroidal occultations. The data-set includes: the raw observations; astrometry at the 1 mas level based on centre of mass or figure (not illumination); where possible the asteroid’s diameter to 5 km or better, and fits to shape models; the separation and diameters of asteroidal satellites; and double star discoveries with typical separations being in the tens of mas or less.