Modeling of Asteroid Spectra – M4AST
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The Orbit of the Minor Planet (7) Iris
ACTA ASTRONOMICA Vol. 43 (1993) pp. 177±181 The Orbit of the Minor Planet (7) Iris by I. Wøodarczyk Astronomical Observatory of the ChorzÂow Planetarium, 41-501 Chorz Âow 1, P.O. box 10, Poland. Received December 17, 1992, ®nal version received in May 1993 ABSTRACT 30 precise positions from the ChorzÂow Observatory and 15 observations from 3 others obser- vatories of (7) Iris made in 1991 are used to determine the orbit of this minor planet. The orbit was determined using once the SAO Catalogue and once the PPM Catalogue. The latter orbit ®ts better to all the observations. Key words: Minor planets ± Astrometry 1. TheChorzow Observations The photographic observations of (7) Iris were made with the photographic camera 200 1000 mm attached to the refractor 300 4500 mm. The geographical 0 00 h m s = = h = coordinates of this refractor are 1 15 58.52, 50 17 31. 8, 328 m. The ORWO plates ZU-21 16 16 cm were measured with the coordinate measur- ing instrument Ascorecord E-2. For the reduction of these plates the Turner method with the complete second- order polynomial was used. On every plate 10 to 14 reference stars were chosen (together 50 stars were considered). The coordinates and the proper motions of all stars were taken once from the SAO Catalogue for the epoch 19500 and once from the PPM Catalogue for the epoch 2000.0. Our positions of (7) Iris obtained with the SAO Catalogue are given in Table 1. There are observations made in 1991 during the opposition of (7) Iris in Nov. -
ESO's VLT Sphere and DAMIT
ESO’s VLT Sphere and DAMIT ESO’s VLT SPHERE (using adaptive optics) and Joseph Durech (DAMIT) have a program to observe asteroids and collect light curve data to develop rotating 3D models with respect to time. Up till now, due to the limitations of modelling software, only convex profiles were produced. The aim is to reconstruct reliable nonconvex models of about 40 asteroids. Below is a list of targets that will be observed by SPHERE, for which detailed nonconvex shapes will be constructed. Special request by Joseph Durech: “If some of these asteroids have in next let's say two years some favourable occultations, it would be nice to combine the occultation chords with AO and light curves to improve the models.” 2 Pallas, 7 Iris, 8 Flora, 10 Hygiea, 11 Parthenope, 13 Egeria, 15 Eunomia, 16 Psyche, 18 Melpomene, 19 Fortuna, 20 Massalia, 22 Kalliope, 24 Themis, 29 Amphitrite, 31 Euphrosyne, 40 Harmonia, 41 Daphne, 51 Nemausa, 52 Europa, 59 Elpis, 65 Cybele, 87 Sylvia, 88 Thisbe, 89 Julia, 96 Aegle, 105 Artemis, 128 Nemesis, 145 Adeona, 187 Lamberta, 211 Isolda, 324 Bamberga, 354 Eleonora, 451 Patientia, 476 Hedwig, 511 Davida, 532 Herculina, 596 Scheila, 704 Interamnia Occultation Event: Asteroid 10 Hygiea – Sun 26th Feb 16h37m UT The magnitude 11 asteroid 10 Hygiea is expected to occult the magnitude 12.5 star 2UCAC 21608371 on Sunday 26th Feb 16h37m UT (= Mon 3:37am). Magnitude drop of 0.24 will require video. DAMIT asteroid model of 10 Hygiea - Astronomy Institute of the Charles University: Josef Ďurech, Vojtěch Sidorin Hygiea is the fourth-largest asteroid (largest is Ceres ~ 945kms) in the Solar System by volume and mass, and it is located in the asteroid belt about 400 million kms away. -
Radar Imaging of Asteroid 7 Iris
Icarus 207 (2010) 285–294 Contents lists available at ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus Radar imaging of Asteroid 7 Iris S.J. Ostro a,1, C. Magri b,*, L.A.M. Benner a, J.D. Giorgini a, M.C. Nolan c, A.A. Hine c, M.W. Busch d, J.L. Margot e a Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA b University of Maine at Farmington, 173 High Street – Preble Hall, Farmington, ME 04938, USA c Arecibo Observatory, HC3 Box 53995, Arecibo, PR 00612, USA d Division of Geological and Planetary Sciences, California Institute of Technology, MC 150-21, Pasadena, CA 91125, USA e Department of Earth and Space Sciences, University of California, Los Angeles, 595 Charles Young Drive East, Box 951567, Los Angeles, CA 90095, USA article info abstract Article history: Arecibo radar images of Iris obtained in November 2006 reveal a topographically complex object whose Received 26 June 2009 gross shape is approximately ellipsoidal with equatorial dimensions within 15% of 253 Â 228 km. The Revised 10 October 2009 radar view of Iris was restricted to high southern latitudes, precluding reliable estimation of Iris’ entire Accepted 7 November 2009 3D shape, but permitting accurate reconstruction of southern hemisphere topography. The most promi- Available online 24 November 2009 nent features, three roughly 50-km-diameter concavities almost equally spaced in longitude around the south pole, are probably impact craters. In terms of shape regularity and fractional relief, Iris represents a Keywords: plausible transition between 50-km-diameter asteroids with extremely irregular overall shapes and Asteroids very large concavities, and very much larger asteroids (Ceres and Vesta) with very regular, nearly convex Radar observations shapes and generally lacking monumental concavities. -
Jjmonl 1503.Pmd
alactic Observer GJohn J. McCarthy Observatory Volume 8, No. 3 March 2015 Gaslight District the birth of a star is hailed in the brightness of its surrounding dust and gas . But why the patch of darkness in the center? Find out more inside, page 19 The John J. McCarthy Observatory Galactic Observer New Milford High School Editorial Committee 388 Danbury Road Managing Editor New Milford, CT 06776 Bill Cloutier Phone/Voice: (860) 210-4117 Production & Design Phone/Fax: (860) 354-1595 www.mccarthyobservatory.org Allan Ostergren Website Development JJMO Staff Marc Polansky It is through their efforts that the McCarthy Observatory Technical Support has established itself as a significant educational and Bob Lambert recreational resource within the western Connecticut Dr. Parker Moreland community. Steve Allison Jim Johnstone Steve Barone Carly KleinStern Colin Campbell Bob Lambert Dennis Cartolano Roger Moore Route Mike Chiarella Parker Moreland, PhD Jeff Chodak Allan Ostergren Bill Cloutier Marc Polansky Cecilia Detrich Joe Privitera Dirk Feather Monty Robson Randy Fender Don Ross Randy Finden Gene Schilling John Gebauer Katie Shusdock Elaine Green Jon Wallace Paul Tina Hartzell Woodell Tom Heydenburg Amy Ziffer In This Issue "OUT THE WINDOW ON YOUR LEFT" ............................... 4 SUNRISE AND SUNSET ...................................................... 15 RUPES RECTA ................................................................ 5 JUPITER AND ITS MOONS ................................................. 15 THE TWINS EXPERIMENT ................................................ -
Surface Material Analysis of S-Type Asteroids: Removing the Space 1 1 1 Weathering Effect from Reflectance Spectrum
Lunar and Planetary Science XXXIV (2003) 2078.pdf SURFACE MATERIAL ANALYSIS OF S-TYPE ASTEROIDS: REMOVING THE SPACE 1 1 1 WEATHERING EFFECT FROM REFLECTANCE SPECTRUM. Y. Ueda M. Miyamoto , T. Mikouchi and 2 1 T. Hiroi , Earth Planet. Sci., Univ. of Tokyo, Hongo 7-3-1, Tokyo 113-0033, Japan ( [email protected] 2 tokyo.ac.jp), Geological Sciences, Brown Univ., RI 02912,USA. Introduction: Recent years, many researchers Data: Reflectance spectra of asteroids in this re- have been observing a lot of asteroid reflectance spec- port were combined from 52 color asteroid survey [1], tra in the UV, visible to NIR at wavelength region SMASSII [2-3]. [e.g., 1-4]. Reflectance spectroscopy of asteroid at this The reflectance spectra of ordinary chondrites Y- range should bring us a lot of information about its 74191 (L3, MB-TXH-084-A) and Y-74646 (LL6, MB- surface materials. Pyroxene and olivine have charac- TXH-085-A) were from RELAB database [14]. They teristic absorption bands in this wavelength range. were pulverized under 25 µm in size. The incident Low-Ca pyroxene has two absorption bands around and emergence angle were 30º and 0º, respectively. 0.9 µm and 1.9 µm. The more Ca and Fe content, the longer both absorption band centers. On the other Results and Discussions: hand, reflectance spectrum of olivine has three com- MGM results: Shown in Figure 1 are the results of plicated absorption bands around 1 µm, and no ab- MGM deconvolution of two S-type asteroids. The sorption feature around 2 µm [5]. -
Occultations and 3D Shape Reconstruction
Asteroidal Occultations High precision astronomy for all Dave Herald A little history • Efforts to observed started in the 1980’s • Predictions initially very poor • Improvements as a result of: – Hipparcos – UCAC2, then UCAC4 – Gaia, then Gaia DR2 => Steady increase in successfully observed occultations, from 39 in 2000 to 502 in 2018 The objective • To accurately measure the size and shape of asteroids • Potentially discover satellites or rings around asteroids The problem • An occultation gives an accurate profile of an asteroid for its orientation at the time of an event • Asteroids are irregular to greater or lesser extents => an accurate asteroid diameter can’t be determined from one or two occultations – only an approximate diameter Asteroid Shape Models • A group of astronomers (largely ‘unpaid’ astronomers) measure the light curves of asteroids in different parts of their orbit • These light curves can be ‘inverted’ to derive the shape of the asteroid (30) Urania Light curve measurements (Blue dots ) and light curve from a model ( Red line ) Shape model ‘issues’ • A shape model has no size – just shape • The inversion process usually results in two different orientations of the axis of rotation – with differing shapes. Inversion process cannot determine which one is correct • The inversion process is complex. Early models were limited to convex surfaces. Over the last few years models with concave surfaces have been developed • Inversion assumes uniform surface reflectivity The two shape models for (30) Urania, with different rotational axes Two shape models for (130) Electra one convex, and one concave, model Fitting occultations to shape models • The next three slides show fits of the occultation of (90) Metis on 2008 Sept 12 to three shape models available for Metis, and the conclusions to be drawn. -
(2000) Forging Asteroid-Meteorite Relationships Through Reflectance
Forging Asteroid-Meteorite Relationships through Reflectance Spectroscopy by Thomas H. Burbine Jr. B.S. Physics Rensselaer Polytechnic Institute, 1988 M.S. Geology and Planetary Science University of Pittsburgh, 1991 SUBMITTED TO THE DEPARTMENT OF EARTH, ATMOSPHERIC, AND PLANETARY SCIENCES IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN PLANETARY SCIENCES AT THE MASSACHUSETTS INSTITUTE OF TECHNOLOGY FEBRUARY 2000 © 2000 Massachusetts Institute of Technology. All rights reserved. Signature of Author: Department of Earth, Atmospheric, and Planetary Sciences December 30, 1999 Certified by: Richard P. Binzel Professor of Earth, Atmospheric, and Planetary Sciences Thesis Supervisor Accepted by: Ronald G. Prinn MASSACHUSES INSTMUTE Professor of Earth, Atmospheric, and Planetary Sciences Department Head JA N 0 1 2000 ARCHIVES LIBRARIES I 3 Forging Asteroid-Meteorite Relationships through Reflectance Spectroscopy by Thomas H. Burbine Jr. Submitted to the Department of Earth, Atmospheric, and Planetary Sciences on December 30, 1999 in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Planetary Sciences ABSTRACT Near-infrared spectra (-0.90 to ~1.65 microns) were obtained for 196 main-belt and near-Earth asteroids to determine plausible meteorite parent bodies. These spectra, when coupled with previously obtained visible data, allow for a better determination of asteroid mineralogies. Over half of the observed objects have estimated diameters less than 20 k-m. Many important results were obtained concerning the compositional structure of the asteroid belt. A number of small objects near asteroid 4 Vesta were found to have near-infrared spectra similar to the eucrite and howardite meteorites, which are believed to be derived from Vesta. -
Orbit and Bulk Density of the OSIRIS-Rex Target Asteroid (101955) Bennu
Accepted by Icarus on February 19, 2014 Orbit and Bulk Density of the OSIRIS-REx Target Asteroid (101955) Bennu Steven R. Chesley∗1, Davide Farnocchia1, Michael C. Nolan2, David Vokrouhlick´y3, Paul W. Chodas1, Andrea Milani4, Federica Spoto4, Benjamin Rozitis5, Lance A. M. Benner1, William F. Bottke6, Michael W. Busch7, Joshua P. Emery8, Ellen S. Howell2, Dante S. Lauretta9, Jean-Luc Margot10, and Patrick A. Taylor2 ABSTRACT The target asteroid of the OSIRIS-REx asteroid sample return mission, (101955) Bennu (formerly 1999 RQ36), is a half-kilometer near-Earth asteroid with an extraor- dinarily well constrained orbit. An extensive data set of optical astrometry from 1999{2013 and high-quality radar delay measurements to Bennu in 1999, 2005, and 2011 reveal the action of the Yarkovsky effect, with a mean semimajor axis drift rate da=dt = (−19:0 ± 0:1) × 10−4 au/Myr or 284 ± 1:5 m=yr. The accuracy of this result depends critically on the fidelity of the observational and dynamical model. As an ex- ample, neglecting the relativistic perturbations of the Earth during close approaches affects the orbit with 3σ significance in da=dt. The orbital deviations from purely gravitational dynamics allow us to deduce the acceleration of the Yarkovsky effect, while the known physical characterization of Bennu allows us to independently model the force due to thermal emissions. The combination of these two analyses yields a bulk density of ρ = 1260 ± 70 kg=m3, which indicates a macroporosity in the range 40 ± 10% for the bulk densities of likely analog meteorites, *[email protected] 1Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA 2Arecibo Observatory, Arecibo, PR, USA 3Charles Univ., Prague, Czech Republic arXiv:1402.5573v1 [astro-ph.EP] 23 Feb 2014 4Univ. -
Long-Term Orbital and Rotational Motions of Ceres and Vesta T
Astronomy & Astrophysics manuscript no. article c ESO 2019 March 18, 2019 Long-term orbital and rotational motions of Ceres and Vesta T. Vaillant, J. Laskar, N. Rambaux, and M. Gastineau ASD/IMCCE, Observatoire de Paris, PSL Université, Sorbonne Université, 77 avenue Denfert-Rochereau, 75014 Paris, France e-mail: [email protected] Received ; accepted ABSTRACT Context. The dwarf planet Ceres and the asteroid Vesta have been studied by the Dawn space mission. They are the two heaviest bodies of the main asteroid belt and have different characteristics. Notably, Vesta appears to be dry and inactive with two large basins at its south pole. Ceres is an ice-rich body with signs of cryovolcanic activity. Aims. The aim of this paper is to determine the obliquity variations of Ceres and Vesta and to study their rotational stability. Methods. The orbital and rotational motions have been integrated by symplectic integration. The rotational stability has been studied by integrating secular equations and by computing the diffusion of the precession frequency. Results. The obliquity variations of Ceres over [−20 : 0] Myr are between 2 and 20◦ and the obliquity variations of Vesta are between 21 and 45◦. The two giant impacts suffered by Vesta modified the precession constant and could have put Vesta closer to the resonance with the orbital frequency 2s6 − sV . Given the uncertainty on the polar moment of inertia, the present Vesta could be in this resonance where the obliquity variations can vary between 17 and 48◦. Conclusions. Although Ceres and Vesta have precession frequencies close to the secular orbital frequencies of the inner planets, their long-term rotations are relatively stable. -
Inner Solar System Material Discovered in the Oort Cloud
Inner Solar System Material Discovered in the Oort Cloud Karen J. Meech1,, Bin Yang,2, Jan Kleyna1, Olivier R. Hainaut,3, Svetlana Berdyugina1,4, Jacqueline V. Keane3, Marco Micheli5-7, Alessandro Morbidelli8, Richard J. Wainscoat1 Teaser: Fresh inner solar systeM Material preserved in the Oort cloud May hold the key to understanding our solar systeM forMation 1Institute for AstronoMy, University of Hawai’i, 2680 Woodlawn Drive, Honolulu, Hawaii 96822-1839, USA. 2European Southern Observatory, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago, Chile 3European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei Munchen, GerMany 4Kiepenheuer Institut fuer Sonnenphysik, Schoeneckstrasse 6, 79104 Freiburg, GerMany 5SSA NEO Coordination Centre, European Space Agency, 00044 Frascati (RM), Italy 6SpaceDyS s.r.l., 56023 Cascina (Pl), Italy 7INAF-IAPS, 00133 RoMa (RM), Italy 8Laboratoire Lagrange, UMR7293, Universite de Nice Sophia-Antipolis, CNRS, Obs. de la Cote d'Azur, Boulevard de l'Observatoire, 06304 Nice Cedex 4, France Manuscript subMitted to Science Advances: Revised, 2016-02-28 Total pages including abstract, text, references, table and figures captions: 21 Total words (abstract): 200 Total words (body text): 2692 Total References for paper + suppleMent: 56 1 We have observed C/2014 S3 (PANSTARRS), a recently discovered object on a coMetary orbit coming from the Oort cloud that is physically siMilar to an inner Main belt rocky S-type asteroid. Recent dynamical Models succeed in reproducing key characteristics of our current solar systeM; some of these Models require significant Migration of the giant planets, while others do not. These Models provide different predictions on the presence of rocky Material expelled froM the inner Solar SysteM in the Oort cloud. -
Cumulative Index to Volumes 1-45
The Minor Planet Bulletin Cumulative Index 1 Table of Contents Tedesco, E. F. “Determination of the Index to Volume 1 (1974) Absolute Magnitude and Phase Index to Volume 1 (1974) ..................... 1 Coefficient of Minor Planet 887 Alinda” Index to Volume 2 (1975) ..................... 1 Chapman, C. R. “The Impossibility of 25-27. Index to Volume 3 (1976) ..................... 1 Observing Asteroid Surfaces” 17. Index to Volume 4 (1977) ..................... 2 Tedesco, E. F. “On the Brightnesses of Index to Volume 5 (1978) ..................... 2 Dunham, D. W. (Letter regarding 1 Ceres Asteroids” 3-9. Index to Volume 6 (1979) ..................... 3 occultation) 35. Index to Volume 7 (1980) ..................... 3 Wallentine, D. and Porter, A. Index to Volume 8 (1981) ..................... 3 Hodgson, R. G. “Useful Work on Minor “Opportunities for Visual Photometry of Index to Volume 9 (1982) ..................... 4 Planets” 1-4. Selected Minor Planets, April - June Index to Volume 10 (1983) ................... 4 1975” 31-33. Index to Volume 11 (1984) ................... 4 Hodgson, R. G. “Implications of Recent Index to Volume 12 (1985) ................... 4 Diameter and Mass Determinations of Welch, D., Binzel, R., and Patterson, J. Comprehensive Index to Volumes 1-12 5 Ceres” 24-28. “The Rotation Period of 18 Melpomene” Index to Volume 13 (1986) ................... 5 20-21. Hodgson, R. G. “Minor Planet Work for Index to Volume 14 (1987) ................... 5 Smaller Observatories” 30-35. Index to Volume 15 (1988) ................... 6 Index to Volume 3 (1976) Index to Volume 16 (1989) ................... 6 Hodgson, R. G. “Observations of 887 Index to Volume 17 (1990) ................... 6 Alinda” 36-37. Chapman, C. R. “Close Approach Index to Volume 18 (1991) .................. -
Astrometric Masses of 21 Asteroids, and an Integrated Asteroid Ephemeris
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Springer - Publisher Connector Celestial Mech Dyn Astr (2008) 100:27–42 DOI 10.1007/s10569-007-9103-8 ORIGINAL ARTICLE Astrometric masses of 21 asteroids, and an integrated asteroid ephemeris James Baer · Steven R. Chesley Received: 28 June 2007 / Revised: 14 October 2007 / Accepted: 25 October 2007 / Published online: 18 December 2007 © Springer Science+Business Media B.V. 2007 Abstract We apply the technique of astrometric mass determination to measure the masses − of 21 main-belt asteroids; the masses of 9 Metis (1.03 ± 0.24 × 10 11 M), 17 Thetis − − (6.17 ± 0.64 × 10 13 M), 19 Fortuna (5.41 ± 0.76 × 10 12 M), and 189 Phthia (1.87 ± − 0.64×10 14 M) appear to be new. The resulting bulk porosities of 11 Parthenope (12±4%) and 16 Psyche (46±16%) are smaller than previously-reported values. Empirical expressions modeling bulk density as a function of mean radius are presented for the C and S taxonomic classes. To accurately model the forces on these asteroids during the mass determination process, we created an integrated ephemeris of the 300 large asteroids used in preparing the DE-405 planetary ephemeris; this new BC-405 integrated asteroid ephemeris also appears useful in other high-accuracy applications. Keywords N-body · Asteroid · Ephemerides · Asteroid masses · Astrometric masses · Asteroid porosity 1 Introduction The technique of astrometric mass determination, in which the deflection of a small body’s trajectory allows us to deduce the mass of a larger perturbing body, may be entering a partic- ularly fruitful period, as near-Earth asteroid (NEA) surveys coincidentally produce a flood of high-precision main-belt asteroid observations.