J/AJ/160/277ivo://CDS.VizieR/J/AJ/160/277doi:10.26093/cds/vizier.51600277CDSFedorets G.Micheli M.Jedicke R.Naidu S.P.Farnocchia D.Granvik M.,Moskovitz N.Schwamb M.E.Weryk R.Wierzchos K.Christensen E.,Pruyne T.Bottke W.F.Ye Q.Wainscoat R.Devogele M.Buchanan L.E.,Djupvik A.A.Faes D.M.Fohring D.Roediger J.Seccull T.Smith A.B.2021-12-07T01:27:58Z2021-03-04T07:20:26ZCDS support team

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

cds-question@unistra.frsolar-systemasteroidsvisible-astronomynarrow-band-photometryinfrared-photometryphotometryWe report on our detailed characterization of Earth's second known temporary natural satellite, or minimoon, asteroid 2020CD3. An artificial origin can be ruled out based on its area-to-mass ratio and broadband photometry, which suggest that it is a silicate asteroid belonging to the S or V complex in asteroid taxonomy. The discovery of 2020CD3 allows for the first time a comparison between known minimoons and theoretical models of their expected physical and dynamical properties. The estimated diameter of 1.2_-0.2_^+0.4^m and geocentric capture approximately a decade after the first known minimoon, 2006RH120, are in agreement with theoretical predictions. The capture duration of 2020CD3 of at least 2.7yr is unexpectedly long compared to the simulation average, but it is in agreement with simulated minimoons that have close lunar encounters, providing additional support for the orbital models. 2020CD3's atypical rotation period, significantly longer than theoretical predictions, suggests that our understanding of meter-scale asteroids needs revision. More discoveries and a detailed characterization of the population can be expected with the forthcoming Vera C. Rubin Observatory Legacy Survey of Space and Time.2020AJ....160..277Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/160/277CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/337 : Gaia DR1 (Gaia Collaboration, 2016)I/345 : Gaia DR2 (Gaia Collaboration, 2018)V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)J/A+A/507/495 : LCs of Datura and 2003 CL5 asteroids (Vokrouhlicky+ 2009)J/A+A/508/1503 : Photometry of 3 main belt asteroids (Marciniak+, 2009)J/A+A/509/A27 : Near-Earth asteroids & QSOs close approaches (Nedelcu+, 2010)J/A+A/511/A49 : Lightcurves of 12 NEAs (Kwiatkowski+, 2010)J/A+A/523/A48 : Gaia photometry (Jordi+, 2010)J/A+A/527/A42 : Photometry of asteroid (21) Lutetia (de Leon+, 2011)J/A+A/529/A107 : Photometry of 4 main belt asteroids (Marciniak+, 2011)J/A+A/545/A131 : Photometry of 8 main belt asteroids (Marciniak+, 2012)J/A+A/546/A72 : Light curves of Flora region asteroids (Kryszczynska+, 2012)J/A+A/559/A106 : Time-series photometry of 2012 DA14 (Terai+, 2013)J/A+A/562/A48 : Light curves of asteroid (25143) Itokawa (Lowry+, 2014)J/A+A/596/A40 : Main-belt asteroids optical light curves (Szabo+, 2016)J/A+A/598/A63 : 2015 TB145 light curve (Mueller+, 2017)J/A+A/619/A123 : Lightcurves of Near-Earth Asteroid 3200 Phaethon (Kim+ 2018)J/A+A/627/A172 : Near-Earth asteroid (1917) Cuyo opt. & IR obs. (Rozek+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/160/277https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/160/277http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/160/277https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/160/277https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/160/277http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/160/277GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/160/277/table2 (Newly acquired or remeasured astrometric data for 2020 CD3)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/160/277/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/160/277/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/160/277/table2?GETtext/xml+votable180.050000true195.906541679.2940.0055555555555555566/8870 8931 8956-8957 9128-9129 9132-9133 9135 10271 10501-10502 10504-10505 26404 26426 26533 279891.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/160/277?format=asciiOpticalInfrareddefaultJ/AJ/160/277/table2Newly acquired or remeasured astrometric data for 2020 CD3recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObs[2020] UTC year of observationtime.epoch;obsRAJ2000[13/14] Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000[4/33] Degree of declination (J2000)pos.eq.dec;meta.mainGmag[19.6/25.6]? Gaia system magnitude (1)magphot.mag;em.opt.VfloatnullableObserMPC observatory codemeta.code;instr.obstychare_RAJ2000[0.03/0.32] Uncerrtainity in RAssstat.error;pos.eq.rafloate_DEJ2000[0.03/0.32] Uncertainity in DEsarcsecstat.error;pos.eq.decfloatTelTelecope usedinstr.setupcharJ/AJ/160/277/table4Lightcurve photometric data for 2020 CD3 obtained with the LDT translated to the r_P1_ filterrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJD[58906/58907] Modified Julian Datedtime.epochdoublemagrp1[22.6/23.2] Magnitude in r_p1_-filtermagphot.mag;em.opt.Rfloatezp[0.02/0.03] Incertitude due to the zero point calibration (1)magstat.errorfloateinst[0.1/0.2] Incertitude due to instrumentmagstat.errorfloat