J/AJ/161/112ivo://CDS.VizieR/J/AJ/161/112doi:10.26093/cds/vizier.51610112CDSLee H.-J.Durech J.Vokrouhlicky D.Pravec P.Moon H.-K.Ryan W.,Kim M.-J.Kim C.-H.Choi Y.-J.Bacci P.Pollock J.Apitzsch R.2021-07-05T12:59:30Z2021-05-03T06:55:42ZCDS support team

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

cds-question@unistra.frasteroidssolar-systeminfrared-photometryvisible-astronomyAsteroid 2012TC4 is a small (~10m) near-Earth object that was observed during its Earth close approaches in 2012 and 2017. Earlier analyses of light curves revealed its excited rotation state. We collected all available photometric data from the two apparitions to reconstruct its rotation state and convex shape model. We show that light curves from 2012 and 2017 cannot be fitted with a single set of model parameters; the rotation and precession periods are significantly different for these two data sets, and they must have changed between or during the two apparitions. Nevertheless, we could fit all light curves with a dynamically self-consistent model assuming that the spin states of 2012TC4 in 2012 and 2017 were different. To interpret our results, we developed a numerical model of its spin evolution in which we included two potentially relevant perturbations: (I) gravitational torque due to the Sun and Earth and (II) radiation torque, known as the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect. Despite our model simplicity, we found that the role of gravitational torques is negligible. Instead, we argue that the observed change of its spin state may be plausibly explained as a result of the YORP torque. To strengthen this interpretation, we verify that (I) the internal energy dissipation due to material inelasticity and (II) an impact with a sufficiently large interplanetary particle are both highly unlikely causes of its observed spin state change. If true, this is the first case where the YORP effect has been detected for a tumbling body.2021AJ....161..112Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/161/112CatalogResearchIsServedByTAP VizieR generic servicerelated-toI/317 : The PPMXL Catalog (Roeser+ 2010)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/550/L11 : Lightcurves of Near-Earth Asteroid 162173 (Kim+ 2013)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/AJ/150/75 : Asteroid light curves from PTF survey (Waszczak+, 2015)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/ApJS/245/29 : Main-belt asteroid photometry from TESS (McNeill+, 2019)J/AJ/159/25 : PS1 light curves and Prots of new asteroids (Lo+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/161/112https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/161/112http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/161/112https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/161/112https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/161/112http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/161/112GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/AJ/161/112/lc2012Combined table from original tablesFluxNormalized fluxphot.flux;arith.ratiodoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJDJulian Date of the observationdtime.epochdoubleTelTelescope identifier (1)meta.id;instr.telcharDateObservation date; YYYY/MM/DD formatobs.param;obscharalphaSolar phase angledegpos.phaseAngfloatJ/AJ/161/112/lc2017Combined table from original tablesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJDJulian Date of the observationdtime.epochdoubleFluxNormalized fluxphot.flux;arith.ratiodoubleTelTelescope identifier (1)meta.id;instr.telcharDateObservation date; YYYY/MM/DD formatobs.param;obscharalphaSolar phase angledegpos.phaseAngfloat