J/ApJ/864/L33ivo://CDS.VizieR/J/ApJ/864/L33doi:10.26093/cds/vizier.18649033CDSShinnaka Y.Kasuga T.Furusho R.Boice D.C.Terai T.Noda H.,Namiki N.Watanabe J.-I.2020-04-29T08:16:56Z2019-09-27T13:42:47ZCDS support team

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

cds-question@unistra.frasteroidspolarimetryvisible-astronomyAs a function of the solar phase angle, {alpha}, the linear polarization degree (referred to the scattering plane, P_r_) of solar system objects is a good diagnostic for understanding the scattering properties of their surface materials. We report the P_r_ of Phaethon over a wide range of {alpha} from 19.1{deg} to 114.3{deg}. The derived phase-polarization curve shows that the maximum of P_r_, Pmax, is >42.4% at {alpha}>114.3{deg}, a value significantly larger than those of the moderate albedo asteroids (Pmax~9%). The phase-polarization curve classifies Phaethon as B-type as well as M- and K-type asteroids, in the polarimetric taxonomy, being compatible with the spectral property. We compute the geometric albedo, p_v_, of 0.14+/-0.04 independently by using an empirical slope-albedo relation, and the derived p_v_ is consistent with previous results determined from mid-infrared spectra and thermophysical modeling. We find no periodic variation of P_r_ in our polarimetric data in the range from 0 up to 7.208hr (e.g., less than twice the rotational period). We also find significant differences between our P_r_ during the 2017 approach toward Earth and that in 2016, implying that Phaethon has a region with different properties for light scattering near its rotational pole.2018ApJ...864L..33Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/864/L33CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/607/A103 : Main-belt asteroids polarimetry. VI. (Gil-Hutton+, 2017)J/AJ/154/168 : NEOWISE: thermal model fits for NEOs and MBAs (Masiero+, 2017)J/A+A/626/A42 : Polarimetry of Main-Belt Asteroids (Lopez-Sisterna+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/864/L33https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/864/L33http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/864/L33https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/864/L33https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/864/L33http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/864/L33GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/ApJ/864/L33/table3Observational results acquired with the Polarimetric Imager for Comets (PICO)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateUT date of the observationtime.epoch;obsnullableJD[97/109] Julian Date minus; JD-2458000 (1)dtime.epochdoublealpha[19.1/114.3] Solar phase angle {alpha}degpos.phaseAngfloatPol[-2.1/54.4] Degree of linear polarization P_r_%phys.polarization.linearfloate_Pol[0.1/6] Uncertainty in Pol%stat.errorfloattheta[1/180] Position angle in the scattering plane {theta}_r_degpos.posAngfloate_theta[0.3/305] Uncertainty in thetadegstat.error;pos.posAngfloat