J/A+A/607/A103ivo://CDS.VizieR/J/A+A/607/A103doi:10.26093/cds/vizier.36070103CDSGil-Hutton R.Garcia-Migani E.2017-12-13T18:23:44Z2017-11-21T07:51:07ZCDS support team

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

cds-question@unistra.frasteroidspolarimetryWe present the results of a polarimetric survey of main-belt asteroids at Complejo Astronomico El Leoncito (CASLEO), San Juan, Argentina. The aims of this survey are to increase the database of asteroid polarimetry and to estimate the diversity in the polarimetric properties of asteroids that belong to different taxonomic classes. The data were obtained using the CASPOL polarimeter at the 2.15 m telescope. CASPOL is a polarimeter based on a CCD detector and a Savart plate. The survey began in 1995 and data on a large sample of asteroids were obtained until 2012. A second period began in 2013 using a polarimeter with a more sensitive detector in order to study small asteroids, families, and special taxonomic groups. We present and analyze the unpublished results for 128 asteroids of different taxonomic types, 55 of them observed for the first time. The observational data allowed us to find probable new cases of Barbarian objects but also two D-type objects, (565) Marbachia and (1481) Tubingia, that seem to have phase-polarization curves with a large inversion angle. The data obtained combined with data from the literature enabled us to find phase-polarization curves for 121 objects of different taxonomic types and to study the relations between several polarimetric and physical parameters. Using an approximation for the phase-polarization curve we found the index of refraction of the surface material and the scatter separation distance for all the objects with known polarimetric parameters. We also found that the inversion angle is a function of the index of refraction of the surface, while the phase angle where the minimum of polarization is produced provides information about the distance between scatter particles or, to some extent, the porosity of the surface.2017A&A...607A.103Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/607/A103CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/astorb : Orbits of Minor Planets (Bowell+ 2014)J/A+A/539/A115 : Main-belt asteroids polarimetry. II. (Gil-Hutton+, 2012)J/A+A/542/A11 : Main-belt asteroids polarimetry. III (Canada-Assandri+, 2012)J/A+A/569/A122 : Main-belt asteroids polarimetry. IV (Gil-Hutton+, 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/607/A103https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/607/A103http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/607/A103https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/607/A103https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/607/A103http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/607/A103GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/607/A103/table1Polarimetric data for the asteroids observedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameAsteroid namemeta.id;meta.maincharObs.DateUT observation datetime.epoch;obsnullableTintTotal integration timestime.epochintalphaPhase angledegpos.phaseAngfloatthetasunPosition angle of the scattering planedegpos.posAngfloatPObserved polarization%phys.polarization.linearfloate_PError in observed polarization%stat.errorfloatthetaPosition angle in the equatorial reference framedegposfloate_thetaError in position angle in the equatorial reference framedegstat.error;pos.posAngfloatPrReduced polarization%phys.polarization.linearfloatTaxBus taxonomic classificationmeta.code.classcharAllDisplay data of both tablesmeta.ref.urlcharJ/A+A/607/A103/table2Values of n and kd for asteroidsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameAsteroid namemeta.id;meta.maincharalphaminPhase angle of the minimum of the phase-polarization curvedegsrc.orbitalfloate_alphaminError in phase angle of the minimum of the phase-polarization curvedegstat.errorfloatPminMinimum of the phase-polarization curve%phys.polarizationfloate_PminError in the minimum of the phase-polarization curve%stat.errorfloatalpha0Inversion angledeginstr.paramfloate_alpha0Error in inversion angledegstat.errorfloathSlope at the inversion angle%.deg**-1meta.code;phys.polarizationfloate_hError in slope at the inversion angle%.deg**-1stat.errorfloatnRefractive indexmeta.code;spect.indexfloatkdWave number times the scatter separationstat.fit.paramfloatTaxBus taxonomic classificationmeta.code.classcharAllDisplay data of both tablesmeta.ref.urlchar