J/AJ/156/139ivo://CDS.VizieR/J/AJ/156/139doi:10.26093/cds/vizier.51560139CDSMommert M.McNeill A.Trilling D.E.Moskovitz N.Delbo' M.2019-03-25T13:54:43Z2019-03-14T14:12:22ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frsolar-systemasteroidsGaia Data Release 2 (Cat. I/345) includes observational data for 14099 pre-selected asteroids. From the sparsely sampled G-band photometry, we derive lower-limit light curve amplitudes for 11665 main belt asteroids (MBA) in order to provide constraints on the distribution of shapes in the asteroid main belt. Assuming a triaxial shape model for each asteroid, defined through the axial aspect ratios a>b and b=c, we find an average b/a=0.80+/-0.04 for the ensemble, which is in agreement with previous results. By combining the Gaia data with asteroid properties from the literature, we investigate possible correlations of the aspect ratio with size, semimajor axis, geometric albedo, and intrinsic color. Based on our model simulations, we find that MBAs greater than 50 km in diameter on average have higher b/a aspect ratios (are rounder) than smaller asteroids. We furthermore find significant differences in the shape distribution of MBAs as a function of the other properties that do not affect the average aspect ratios. We conclude that a more detailed investigation of shape distribution correlations requires a larger data sample than is provided in Gaia Data Release 2.2018AJ....156..139Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/156/139CatalogResearchIsServedByTAP VizieR generic servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)J/ApJ/759/L8 : WISE/NEOWISE observations of main belt asteroidsJ/ApJ/791/121 : NIR albedos of main-belt asteroids (Masiero+, 2014)J/A+A/578/A42 : Main Belt asteroids observed by Spitzer (Ryan+, 2015)J/A+A/596/A40 : Main-belt asteroids optical light curves (Szabo+, 2016)J/A+A/620/A91 : New asteroid models (Durech+, 2018)J/ApJS/237/19 : KMTNet LCs of ~1000 main-belt asteroids (Erasmus+, 2018)http://minorplanetcenter.net/ : Minor Planet Center databasehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/156/139https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/156/139http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/156/139https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/156/139https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/156/139http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/156/139GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/AJ/156/139/table1DR2 (Cat. I/345) main belt asteroid lightcurve amplitudes and auxiliary datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMPC[8/159493] MPC target numbermeta.idintAmp[0.02/1.97] Lower limit lightcurve amplitude (1)magsrc.var.amplitude;stat.minfloatNobs[4/52] Number of Gaia DR2 observations (2)meta.numberintb_alpha[7.6/33.8] Lower limit solar phase angle, {alpha} (3)degpos.phaseAng;stat.minfloatB_alpha[9.4/37.9] Upper limit solar phase angle, {alpha} (3)degpos.phaseAng;stat.maxfloatG12[-0.52/1.52] Adopted photometric G_12_ slope parameter as defined by Muinonen et al. (2010Icar..209..542M)stat.fit.paramfloatE_G12[0/0.95] Upper G_12_ 1{sigma} uncertaintystat.error;stat.maxfloate_G12[0/0.95] Lower G_12_ 1{sigma} uncertaintystat.error;stat.minfloatr_G12[ov] G_12_ slope parameter source (4)meta.ref;pos.framechara*[-0.3/0.3]? SDSS intrinsic color parameter (5)phot.colorfloatnullablea[1.578/4.302] Semi-major axis (6)AUphys.size.smajAxisfloatDiam[1.6/298.8]? Target diameter (7)kmphys.size.diameterfloatnullablepV[0.02/1]? Target geometric albedo, V band (7)phys.albedofloatnullableGaiaDisplay data from Gaia DR2 (Cat. I/345)meta.ref.urlchar