DOCSLIB.ORG

New and Updated Convex Shape Models of Asteroids Based on Optical Data from a Large Collaboration Network J

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
New and Updated Convex Shape Models of Asteroids Based on Optical Data from a Large Collaboration Network J Astronomy & Astrophysics manuscript no. hanus_2015_models_AA_final c ESO 2015 October 21, 2015 New and updated convex shape models of asteroids based on optical data from a large collaboration network J. Hanuš1,2∗, J. Durechˇ 3, D.A. Oszkiewicz4, R. Behrend5, B. Carry2, M. Delbo’2, O. Adam6, V. Afonina7, R. Anquetin8, P. Antonini9, L. Arnold6, M. Audejean10, P. Aurard6, M. Bachschmidt6, B. Baduel6, E. Barbotin11, P. Barroy8, P. Baudouin12, L. Berard6, N. Berger13, L. Bernasconi14, J-G. Bosch15, S. Bouley8, I. Bozhinova16, J. Brinsfield17, L. Brunetto18, G. Canaud8, J. Caron19,20, F. Carrier21, G. Casalnuovo22, S. Casulli23, M. Cerda24, S. Charbonnel25, B. Chinaglia22, A. Cikota26, F. Colas8, J-F. Coliac27, A. Collet6, J. Coloma28,29, M. Conjat2, E. Conseil30, R. Costa28,31, R. Crippa32, M. Cristofanelli33, Y. Darmedji34, A. Debackere35, A. Decock34, Q. Déhais36, T. Déléage35, S. Delmelle34, C. Demeautis37, M. Drozdz38, G. Dubos8, T. Dulcamara6, M. Dumont34, R. Durkee39, R. Dymock40, N. Esseiva41, R. Esseiva41, M. Esteban24,42, T. Fauchez34, M. Fauerbach43, M. Fauvaud44,45, S. Fauvaud44,45,8, E. Forné28,46†, D. Fradet8, J. Garlitz47, O. Gerteis6, C. Gillier48, M. Gillon34, R. Giraud34, J-P. Godard8, R. Goncalves49, H. Hamanowa50, H. Hamanowa50, K. Hay16, S. Hellmich51, S. Heterier52,53, D. Higgins54, R. Hirsch4, G. Hodosan16, M. Hren26, A. Hygate16, N. Innocent6, H. Jacquinot55, S. Jawahar56, E. Jehin34, L. Jerosimic26, A. Klotz57,58,6, W. Koff59, P. Korlevic26, E. Kosturkiewicz38, P. Krafft6, Y. Krugly60, F. Kugel19, O. Labrevoir6, J. Lecacheux8, M. Lehký61, A. Leroy8,62,63, B. Lesquerbault6, M.J. Lopez-Gonzales64, M. Lutz6, B. Mallecot8, J. Manfroid34, F. Manzini32, A. Marciniak4, A. Martin65,66, B. Modave6, R. Montaigut8,48,63, J. Montier52,53, E. Morelle27, B. Morton16, S. Mottola51, R. Naves67, J. Nomen26, J. Oey68, W. Ogloza38, M. Paiella33, H. Pallares28,69, A. Peyrot58, F. Pilcher70, J-F. Pirenne6, P. Piron6, M. Polinska4, M. Polotto6, R. Poncy71, J.P. Previt53, F. Reignier72, D. Renauld6, D. Ricci34, F. Richard45, C. Rinner73, V. Risoldi33, D. Robilliard53, D. Romeuf74, G. Rousseau75, R. Roy76, J. Ruthroff77, P.A. Salom24,42, L. Salvador6, S. Sanchez26, T. Santana-Ros4, A. Scholz16, G. Séné6, B. Skiff78, K. Sobkowiak4, P. Sogorb79, F. Soldán80, A. Spiridakis35, E. Splanska6, S. Sposetti81, D. Starkey82, R. Stephens83, A. Stiepen34, R. Stoss26, J. Strajnic6, J-P. Teng58, G. Tumolo84, A. Vagnozzi33, B. Vanoutryve6, J.M. Vugnon45, B.D. Warner83, M. Waucomont6, O. Wertz34, M. Winiarski38†, and M. Wolf3 (Affiliations can be found after the references) Received x-x-2012 / Accepted x-x-2012 ABSTRACT Context. Asteroid modeling efforts in the last decade resulted in a comprehensive dataset of almost 400 convex shape models and their rotation states. This amount already provided a deep insight into physical properties of main-belt asteroids or large collisional families. Going into finer details (e.g., smaller collisional families, asteroids with sizes .20 km) requires knowledge of physical parameters of more objects. Aims. We aim to increase the number of asteroid shape models and rotation states. Such results are an important input for various further studies such as analysis of asteroid physical properties in different populations, including smaller collisional families, thermophysical modeling, and scaling shape models by disk-resolved images, or stellar occultation data. This provides, in combination with known masses, bulk density estimates, but constrains also theoretical collisional and evolutional models of the Solar System. Methods. We use all available disk-integrated optical data (i.e., classical dense-in-time photometry obtained from public databases and through a large collaboration network as well as sparse-in-time individual measurements from a few sky surveys) as an input for the convex inversion method, and derive 3D shape models of asteroids, together with their rotation periods and orientations of rotation axes. The key ingredient is the support of more that one hundred observers who submit their optical data to publicly available databases. Results. We present updated shape models for 36 asteroids, for which mass estimates are currently available in the literature or their masses will be most likely determined from their gravitational influence on smaller bodies, which orbital deflection will be observed by the ESA Gaia astrometric mission. This was achieved by using additional optical data from recent apparitions for the shape optimization. Moreover, we also present new shape model determinations for 250 asteroids, including 13 Hungarias and 3 near-Earth asteroids. 1. Introduction on disk-integrated dense-in-time optical data (e.g., Torppa et al. 2003; Slivan et al. 2003; Michałowski et al. 2005; Marciniak Asteroid modeling efforts in the last decade resulted in an ex- et al. 2009, 2011). Combining dense-in-time data with sparse-in- tensive dataset of almost 400 convex shape models and rota- time measurements from large sky surveys, or using only sparse- tion states (see the review by Durechˇ et al. 2015a). The major- in-time data increased the number of available shape models by ity of these models was determined by the lightcurve inversion a factor of 4 (Durechˇ et al. 2009; Hanuš et al. 2011, 2013a,c). method (LI) developed by Kaasalainen & Torppa (2001) and Future data from Gaia, PanSTARRS, and LSST should result in Kaasalainen et al. (2001). About one hundred models are based 1 J. Hanuš et al.: New and updated shape models of asteroids an increase of shape models by an order of at least one mag- compensate by average fitting to the disk-resolved data. As a nitude (Durechˇ et al. 2005). The methods that will be used for result, the overestimation in the volume is smaller than would analysis of these future data of unprecedented amount and qual- correspond to the convex hull. The volume can then provide, in ity by the means of complex shape modeling are similar to those combination with mass estimates, realistic values of bulk densi- applied here and developed within the scope of our recent stud- ties (Durechˇ et al. 2011; Hanuš et al. 2013b). ies. The mass is one of the most challenging parameter to mea- Most asteroid shape models derived by the lightcurve inver- sure for an asteroid. Mass estimates are now available for 280 as- sion method and their optical data are available in the Database teroids, but only 113 of these are more precise than 20% (Carry of Asteroid Models from Inversion Techniques (DAMIT1, 2012; Scheeres et al. 2015). However, the situation is expected Durechˇ et al. 2010). to improve significantly in a near future. The observations of We would like to emphasize and acknowledge that the shape the ESA Gaia astrometric satellite will provide masses accurate modeling stands on the shoulders of 100s of observers, often am- to better than 50% for ≈150 asteroids (and for ≈50 with an ac- ateurs, that are regularly obtaining photometric data with their curacy better than 10%, Mouret et al. 2007, 2008) by the orbit small and mid-sized telescopes, which significantly contributed deflection method. The advantage of the masses determined by to the large progress of the shape modeling field in the last Gaia is in the uniquenessof themission:we should obtaina com- decade. Although there is much more sparse than dense data prehensive sample with well-described biases (e.g., the current available, the latter will always remain important, because their mass estimates are currently strongly biased towards the inner much higher photometric accuracy and rotation coverage leads main belt). to higher quality shape models. This is a typical example of To maximize the possible outcome by the means of density great interaction between the professional and amateur commu- determinations, we focus on determination of shape models for nity (Mousis et al. 2014). asteroids, for which accurate mass estimates are available or will Knowing the rotational parameters and shapes of asteroids is most likely be determined by Gaia. Moreover,it is also important very important for numerous applications. The large amount of to update shape models for such asteroids by using recently ob- currently known asteroid models provided already a deep insight tained optical data. Doing so, we can provide better constraints into physical properties of main-belt asteroids and large colli- on the rotational phase (i.e., on the asteroid orientation, which sional families: (i) an excess of prograde rotators within main- is important for scaling the size) of these asteroids due to the belt asteroids (MBAs) larger than ∼50 km in diameter, predicted improvement of the rotation period, and more accurate rotation by numerical simulations (Johansen & Lacerda 2010), was con- state and shape parameters. firmed by Kryszczynska´ et al. (2007);Hanuš et al. (2011); (ii) an Convex models, together with thermal infrared observations, excess of retrograde rotators within near-Earth asteroids (NEAs) have also been used as inputs for thermophysical modeling, en- is consistent with the fact that most of the NEAs come from abling the determination of geometric visible albedo, size and surface properties (e.g., Müller et al. 2011; Hanuš et al. 2015). the ν6 resonance (La Spina et al. 2004). To enter the ν6 res- onance via Yarkovsky effect2 the object must be a retrograde This application is particularly important because it can make rotator; (iii) an anisotropy of spin-axis directions of MBAs as- use of the large sample of infrared data for more than 100000 teroids with diameters . 30 km and NEAs was revealed and asteroids acquired by the NASA’s Wide-field Infrared Survey explained by the YORP effect3, collisions and mass shedding Explorer (WISE). The missing input here are shape models of (Hanuš et al. 2011; Pravec et al. 2012); (iv) a bi-modality of pro- sufficient quality (Delbo’ et al. 2015). grade and retrograde rotators symmetric with respect to the cen- Moreover,convex models or at least rotational states are usu- ter of the family is caused by the combined Yarkovsky, YORP ally necessary inputs for more complex shape modeling, which and collisional dynamical evolution (Kryszczynska´ 2013; Hanuš can be performed if additional data such as stellar occultations, et al.
Load more

Recommended publications
  • The Minor Planet Bulletin 44 (2017) 142
    THE MINOR PLANET BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS VOLUME 44, NUMBER 2, A.D. 2017 APRIL-JUNE 87. 319 LEONA AND 341 CALIFORNIA – Lightcurves from all sessions are then composited with no TWO VERY SLOWLY ROTATING ASTEROIDS adjustment of instrumental magnitudes. A search should be made for possible tumbling behavior. This is revealed whenever Frederick Pilcher successive rotational cycles show significant variation, and Organ Mesa Observatory (G50) quantified with simultaneous 2 period software. In addition, it is 4438 Organ Mesa Loop useful to obtain a small number of all-night sessions for each Las Cruces, NM 88011 USA object near opposition to look for possible small amplitude short [email protected] period variations. Lorenzo Franco Observations to obtain the data used in this paper were made at the Balzaretto Observatory (A81) Organ Mesa Observatory with a 0.35-meter Meade LX200 GPS Rome, ITALY Schmidt-Cassegrain (SCT) and SBIG STL-1001E CCD. Exposures were 60 seconds, unguided, with a clear filter. All Petr Pravec measurements were calibrated from CMC15 r’ values to Cousins Astronomical Institute R magnitudes for solar colored field stars. Photometric Academy of Sciences of the Czech Republic measurement is with MPO Canopus software. To reduce the Fricova 1, CZ-25165 number of points on the lightcurves and make them easier to read, Ondrejov, CZECH REPUBLIC data points on all lightcurves constructed with MPO Canopus software have been binned in sets of 3 with a maximum time (Received: 2016 Dec 20) difference of 5 minutes between points in each bin.
    [Show full text]
  • An Anisotropic Distribution of Spin Vectors in Asteroid Families
    Astronomy & Astrophysics manuscript no. families c ESO 2018 August 25, 2018 An anisotropic distribution of spin vectors in asteroid families J. Hanuš1∗, M. Brož1, J. Durechˇ 1, B. D. Warner2, J. Brinsfield3, R. Durkee4, D. Higgins5,R.A.Koff6, J. Oey7, F. Pilcher8, R. Stephens9, L. P. Strabla10, Q. Ulisse10, and R. Girelli10 1 Astronomical Institute, Faculty of Mathematics and Physics, Charles University in Prague, V Holešovickáchˇ 2, 18000 Prague, Czech Republic ∗e-mail: [email protected] 2 Palmer Divide Observatory, 17995 Bakers Farm Rd., Colorado Springs, CO 80908, USA 3 Via Capote Observatory, Thousand Oaks, CA 91320, USA 4 Shed of Science Observatory, 5213 Washburn Ave. S, Minneapolis, MN 55410, USA 5 Hunters Hill Observatory, 7 Mawalan Street, Ngunnawal ACT 2913, Australia 6 980 Antelope Drive West, Bennett, CO 80102, USA 7 Kingsgrove, NSW, Australia 8 4438 Organ Mesa Loop, Las Cruces, NM 88011, USA 9 Center for Solar System Studies, 9302 Pittsburgh Ave, Suite 105, Rancho Cucamonga, CA 91730, USA 10 Observatory of Bassano Bresciano, via San Michele 4, Bassano Bresciano (BS), Italy Received x-x-2013 / Accepted x-x-2013 ABSTRACT Context. Current amount of ∼500 asteroid models derived from the disk-integrated photometry by the lightcurve inversion method allows us to study not only the spin-vector properties of the whole population of MBAs, but also of several individual collisional families. Aims. We create a data set of 152 asteroids that were identified by the HCM method as members of ten collisional families, among them are 31 newly derived unique models and 24 new models with well-constrained pole-ecliptic latitudes of the spin axes.
    [Show full text]
  • Asteroid Regolith Weathering: a Large-Scale Observational Investigation
    University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 5-2019 Asteroid Regolith Weathering: A Large-Scale Observational Investigation Eric Michael MacLennan University of Tennessee, [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Recommended Citation MacLennan, Eric Michael, "Asteroid Regolith Weathering: A Large-Scale Observational Investigation. " PhD diss., University of Tennessee, 2019. https://trace.tennessee.edu/utk_graddiss/5467 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by Eric Michael MacLennan entitled "Asteroid Regolith Weathering: A Large-Scale Observational Investigation." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Doctor of Philosophy, with a major in Geology. Joshua P. Emery, Major Professor We have read this dissertation and recommend its acceptance: Jeffrey E. Moersch, Harry Y. McSween Jr., Liem T. Tran Accepted for the Council: Dixie L. Thompson Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) Asteroid Regolith Weathering: A Large-Scale Observational Investigation A Dissertation Presented for the Doctor of Philosophy Degree The University of Tennessee, Knoxville Eric Michael MacLennan May 2019 © by Eric Michael MacLennan, 2019 All Rights Reserved.
    [Show full text]
  • The Minor Planet Bulletin
    THE MINOR PLANET BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS VOLUME 35, NUMBER 3, A.D. 2008 JULY-SEPTEMBER 95. ASTEROID LIGHTCURVE ANALYSIS AT SCT/ST-9E, or 0.35m SCT/STL-1001E. Depending on the THE PALMER DIVIDE OBSERVATORY: binning used, the scale for the images ranged from 1.2-2.5 DECEMBER 2007 – MARCH 2008 arcseconds/pixel. Exposure times were 90–240 s. Most observations were made with no filter. On occasion, e.g., when a Brian D. Warner nearly full moon was present, an R filter was used to decrease the Palmer Divide Observatory/Space Science Institute sky background noise. Guiding was used in almost all cases. 17995 Bakers Farm Rd., Colorado Springs, CO 80908 [email protected] All images were measured using MPO Canopus, which employs differential aperture photometry to determine the values used for (Received: 6 March) analysis. Period analysis was also done using MPO Canopus, which incorporates the Fourier analysis algorithm developed by Harris (1989). Lightcurves for 17 asteroids were obtained at the Palmer Divide Observatory from December 2007 to early The results are summarized in the table below, as are individual March 2008: 793 Arizona, 1092 Lilium, 2093 plots. The data and curves are presented without comment except Genichesk, 3086 Kalbaugh, 4859 Fraknoi, 5806 when warranted. Column 3 gives the full range of dates of Archieroy, 6296 Cleveland, 6310 Jankonke, 6384 observations; column 4 gives the number of data points used in the Kervin, (7283) 1989 TX15, 7560 Spudis, (7579) 1990 analysis. Column 5 gives the range of phase angles.
    [Show full text]
  • A Study of Asteroid Pole-Latitude Distribution Based on an Extended
    Astronomy & Astrophysics manuscript no. aa˙2009 c ESO 2018 August 22, 2018 A study of asteroid pole-latitude distribution based on an extended set of shape models derived by the lightcurve inversion method 1 1 1 2 3 4 5 6 7 J. Hanuˇs ∗, J. Durechˇ , M. Broˇz , B. D. Warner , F. Pilcher , R. Stephens , J. Oey , L. Bernasconi , S. Casulli , R. Behrend8, D. Polishook9, T. Henych10, M. Lehk´y11, F. Yoshida12, and T. Ito12 1 Astronomical Institute, Faculty of Mathematics and Physics, Charles University in Prague, V Holeˇsoviˇck´ach 2, 18000 Prague, Czech Republic ∗e-mail: [email protected] 2 Palmer Divide Observatory, 17995 Bakers Farm Rd., Colorado Springs, CO 80908, USA 3 4438 Organ Mesa Loop, Las Cruces, NM 88011, USA 4 Goat Mountain Astronomical Research Station, 11355 Mount Johnson Court, Rancho Cucamonga, CA 91737, USA 5 Kingsgrove, NSW, Australia 6 Observatoire des Engarouines, 84570 Mallemort-du-Comtat, France 7 Via M. Rosa, 1, 00012 Colleverde di Guidonia, Rome, Italy 8 Geneva Observatory, CH-1290 Sauverny, Switzerland 9 Benoziyo Center for Astrophysics, The Weizmann Institute of Science, Rehovot 76100, Israel 10 Astronomical Institute, Academy of Sciences of the Czech Republic, Friova 1, CZ-25165 Ondejov, Czech Republic 11 Severni 765, CZ-50003 Hradec Kralove, Czech republic 12 National Astronomical Observatory, Osawa 2-21-1, Mitaka, Tokyo 181-8588, Japan Received 17-02-2011 / Accepted 13-04-2011 ABSTRACT Context. In the past decade, more than one hundred asteroid models were derived using the lightcurve inversion method. Measured by the number of derived models, lightcurve inversion has become the leading method for asteroid shape determination.
    [Show full text]
  • Solar System Objects in the ISOPHOT 170 Μm Serendipity Survey
    A&A 389, 665–679 (2002) Astronomy DOI: 10.1051/0004-6361:20020596 & c ESO 2002 Astrophysics Solar system objects in the ISOPHOT 170 µm serendipity survey? T. G. M¨uller1,2, S. Hotzel3, and M. Stickel3 1 Max-Planck-Institut f¨ur extraterrestrische Physik, Giessenbachstraße, 85748 Garching, Germany 2 ISO Data Centre, Astrophysics Division, Space Science Department of ESA, Villafranca, PO Box 50727, 28080 Madrid, Spain (until Dec. 2001) 3 ISOPHOT Data Centre, Max-Planck-Institut f¨ur Astronomie, K¨onigstuhl 17, 69117 Heidelberg, Germany Received 14 January 2002 / Accepted 12 March 2002 Abstract. The ISOPHOT Serendipity Survey (ISOSS) covered approximately 15% of the sky at a wavelength of 170 µm while the ISO satellite was slewing from one target to the next. By chance, ISOSS slews went over many solar system objects (SSOs). We identified the comets, asteroids and planets in the slews through a fast and effective search procedure based on N-body ephemeris and flux estimates. The detections were analysed from a calibration and scientific point of view. Through the measurements of the well-known asteroids Ceres, Pallas, Juno and Vesta and the planets Uranus and Neptune it was possible to improve the photometric calibration of ISOSS and to extend it to higher flux regimes. We were also able to establish calibration schemes for the important slew end data. For the other asteroids we derived radiometric diameters and albedos through a recent thermophysical model. The scientific results are discussed in the context of our current knowledge of size, shape and albedos, derived from IRAS observations, occultation measurements and lightcurve inversion techniques.
    [Show full text]
  • The Minor Planet Bulletin Is Open to Papers on All Aspects of 6500 Kodaira (F) 9 25.5 14.8 + 5 0 Minor Planet Study
    THE MINOR PLANET BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS VOLUME 32, NUMBER 3, A.D. 2005 JULY-SEPTEMBER 45. 120 LACHESIS – A VERY SLOW ROTATOR were light-time corrected. Aspect data are listed in Table I, which also shows the (small) percentage of the lightcurve observed each Colin Bembrick night, due to the long period. Period analysis was carried out Mt Tarana Observatory using the “AVE” software (Barbera, 2004). Initial results indicated PO Box 1537, Bathurst, NSW, Australia a period close to 1.95 days and many trial phase stacks further [email protected] refined this to 1.910 days. The composite light curve is shown in Figure 1, where the assumption has been made that the two Bill Allen maxima are of approximately equal brightness. The arbitrary zero Vintage Lane Observatory phase maximum is at JD 2453077.240. 83 Vintage Lane, RD3, Blenheim, New Zealand Due to the long period, even nine nights of observations over two (Received: 17 January Revised: 12 May) weeks (less than 8 rotations) have not enabled us to cover the full phase curve. The period of 45.84 hours is the best fit to the current Minor planet 120 Lachesis appears to belong to the data. Further refinement of the period will require (probably) a group of slow rotators, with a synodic period of 45.84 ± combined effort by multiple observers – preferably at several 0.07 hours. The amplitude of the lightcurve at this longitudes. Asteroids of this size commonly have rotation rates of opposition was just over 0.2 magnitudes.
    [Show full text]
  • Absolute Magnitudes of Asteroids and a Revision of Asteroid Albedo Estimates from WISE Thermal Observations ⇑ Petr Pravec A, , Alan W
    Icarus 221 (2012) 365–387 Contents lists available at SciVerse ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations ⇑ Petr Pravec a, , Alan W. Harris b, Peter Kušnirák a, Adrián Galád a,c, Kamil Hornoch a a Astronomical Institute, Academy of Sciences of the Czech Republic, Fricˇova 1, CZ-25165 Ondrˇejov, Czech Republic b 4603 Orange Knoll Avenue, La Cañada, CA 91011, USA c Modra Observatory, Department of Astronomy, Physics of the Earth, and Meteorology, FMFI UK, Bratislava SK-84248, Slovakia article info abstract Article history: We obtained estimates of the Johnson V absolute magnitudes (H) and slope parameters (G) for 583 main- Received 27 February 2012 belt and near-Earth asteroids observed at Ondrˇejov and Table Mountain Observatory from 1978 to 2011. Revised 27 July 2012 Uncertainties of the absolute magnitudes in our sample are <0.21 mag, with a median value of 0.10 mag. Accepted 28 July 2012 We compared the H data with absolute magnitude values given in the MPCORB, Pisa AstDyS and JPL Hori- Available online 13 August 2012 zons orbit catalogs. We found that while the catalog absolute magnitudes for large asteroids are relatively good on average, showing only little biases smaller than 0.1 mag, there is a systematic offset of the cat- Keywords: alog values for smaller asteroids that becomes prominent in a range of H greater than 10 and is partic- Asteroids ularly big above H 12. The mean (H H) value is negative, i.e., the catalog H values are Photometry catalog À Infrared observations systematically too bright.
    [Show full text]
  • • Ii/ O I 119 Althaea
    Asteroids, Comets, Meteors 1991, pp. 413-416 Lunar and Planetary Institute, Houston, 1992 Near Infrared Reflectance Spectra: Applications to F V Problems in Asteroid - Meteorite Relationships Lucy A. McFadden & Alan B. Chamberlin California Space Institute, University of California, San Diego, La Jolla, CA 92093 INTRODUCTION _"An observing program cleslgned t'o search for evidence of ordinary chondrite parentbodies near the 3:1 Kirkwood Gap was carried out in i985 _ I986. Studies by Wisdom (1985), Wetherill (1985), _ subsequent work by Milani et al. (1989) indicate that the 3:1 Kirkwood gap is the most probable source region for the majority of ordinary chondrite meteorite§. _ignrc 1 shows the location (in eccentricity vs scmimajor-axis space) of the observed asteroids as wel! as the chaotic zbne+ of tim 3:1 (Wisdom, 1983) and the 5:2 Kirkwood Gaps. " The diversity of the reflectance spectra among this small data set is surprising. Early work by Gaffey and McCord (1978) showed that the inner region of the main asteroid belt is dominated by high albedo objects with mafic silicate surfaces. One would expect to see mostly spectra with 1- and 2-pro absorption bands based on this earlier work. Only 5 (of 12) spectra have these expected features. The distribution of taxonomic types presented by Gradie and Tedesco (1982) is in most cases a useful simplification of the compositional structure of the asteroid belt. The range of sI)cctral characteristics seen with higher resolution in tim near-IR has not been previously reported and is not represented in the standard asteroid taxonomy.
    [Show full text]
  • A Photometric Search for Active Main Belt Asteroids S
    Astronomy & Astrophysics manuscript no. MBCsearch c ESO 2018 May 15, 2018 A photometric search for active Main Belt asteroids S. Cikota1, J. L. Ortiz2, A. Cikota3, N. Morales2, and G. Tancredi4 1 Physics Department, University of Split, Nikole Tesle 12, 21000 Split, Croatia. e-mail: [email protected] 2 Instituto de Astrofísica de Andalucía - CSIC, Apt 3004, 18008 Granada, Spain. 3 Institute for Astro- and Particle Physics, University of Innsbruck, Technikerstr. 25/8, A-6020 Innsbruck, Austria. 4 Observatorio Astronómico Los Molinos DICYT-MEC Cno. de los Molinos 5769, 12400 Montevideo, Uruguay. May 15, 2018 ABSTRACT It is well known that some Main Belt asteroids show comet-like features. A representative example is the first known Main Belt comet 133P/(7968) Elst-Pizarro. If the mechanisms causing this activity are too weak to develop visually evident comae or tails, the objects stay unnoticed. We are presenting a novel way to search for active asteroids, based on looking for objects with deviations from their expected brightnesses in a database. Just by using the MPCAT-OBS Observation Archive we have found five new candidate objects that possibly show a type of comet-like activity, and the already known Main Belt comet 133P/(7968) Elst-Pizarro. Four of the new candidates, (315) Constantia, (1026) Ingrid, (3646) Aduatiques, and (24684) 1990 EU4, show brightness deviations independent of the object’s heliocentric distance, while (35101) 1991 PL16 shows deviations dependent on its heliocentric distance, which could be an indication of a thermal triggered mechanism. The method could be implemented in future sky survey programmes to detect outbursts on Main Belt objects almost simultaneously with their occurrence.
    [Show full text]
  • The Minor Planet Bulletin Semi-Major Axis of 2.317 AU, Eccentricity 0.197, Inclination 7.09 (Warner Et Al., 2018)
    THE MINOR PLANET BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS VOLUME 45, NUMBER 3, A.D. 2018 JULY-SEPTEMBER 215. LIGHTCURVE ANALYSIS FOR TWO NEAR-EARTH 320ʺ/min during the close approach. The eclipse was observed, ASTEROIDS ECLIPSED BY EARTH’S SHADOW within minutes of the original prediction. Preliminary rotational and eclipse lightcurves were made available soon after the close Peter Birtwhistle approach (Birtwhistle, 2012; Birtwhistle, 2013; Miles, 2013) but it Great Shefford Observatory should be noted that a possible low amplitude 8.7 h period (Miles, Phlox Cottage, Wantage Road 2013) has been discounted in this analysis. Great Shefford, Berkshire, RG17 7DA United Kingdom Several other near-Earth asteroids are known to have been [email protected] eclipsed by the Earth’s shadow, e.g. 2008 TC3 and 2014 AA (both before impacting Earth), 2012 KT42, and 2016 VA (this paper) (Received 2018 March18) but internet searches have not found any eclipse lightcurves. The asteroid lightcurve database (LCDB; Warner et al., 2009) lists a Photometry was obtained from Great Shefford reference to an unpublished result for 2012 XE54 by Pollock Observatory of near-Earth asteroids 2012 XE54 in 2012 (2013) without lightcurve details, but these have been provided on and 2016 VA in 2016 during close approaches. A request and give the rotation period as 0.02780 ± 0.00002 h, superfast rotation period has been determined for 2012 amplitude 0.33 mag derived from 101 points over a period of 30 XE54 and H-G magnitude system coefficients have been minutes for epoch 2012 Dec 10.2 UT at phase angle 19.5°, estimated for 2016 VA.
    [Show full text]
  • The Minor Planet Bulletin Lost a Friend on Agreement with That Reported by Ivanova Et Al
    THE MINOR PLANET BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS VOLUME 33, NUMBER 3, A.D. 2006 JULY-SEPTEMBER 49. LIGHTCURVE ANALYSIS FOR 19848 YEUNGCHUCHIU Kwong W. Yeung Desert Eagle Observatory P.O. Box 105 Benson, AZ 85602 [email protected] (Received: 19 Feb) The lightcurve for asteroid 19848 Yeungchuchiu was measured using images taken in November 2005. The lightcurve was found to have a synodic period of 3.450±0.002h and amplitude of 0.70±0.03m. Asteroid 19848 Yeungchuchiu was discovered in 2000 Oct. by the author at Desert Beaver Observatory, AZ, while it was about one degree away from Jupiter. It is named in honor of my father, The amplitude of 0.7 magnitude indicates that the long axis is Yeung Chu Chiu, who is a businessman in Hong Kong. I hoped to about 2 times that of the shorter axis, as seen from the line of sight learn the art of photometry by studying the lightcurve of 19848 as at that particular moment. Since both the maxima and minima my first solo project. have similar “height”, it’s likely that the rotational axis was almost perpendicular to the line of sight. Using a remote 0.46m f/2.8 reflector and Apogee AP9E CCD camera located in New Mexico Skies (MPC code H07), images of Many amateurs may have the misconception that photometry is a the asteroid were obtained on the nights of 2005 Nov. 20 and 21. very difficult science. After this learning exercise I found that, at Exposures were 240 seconds.
    [Show full text]