The two rings of (50000) Quaoar

DOI

Quaoar is a classical trans-Neptunian object (TNO) with an area-equivalent diameter of 1100 km and an orbital semi-major axis of 43.3 astronomical units. Based on stellar occultations observed between 2018 and 2021, an inhomogeneous ring (Q1R, i.e., Quaoar's first ring) has been detected around this body. A new stellar occultation by Quaoar was observed on August 9, 2022, with the aim of improving Quaoar's shape models and the physical parameters of Q1R, while searching for additional material around the body. The occultation provided nine effective chords across Quaoar, pinning down its size, shape, and astrometric position. Large facilities, such as Gemini North and the Canada-France-Hawaii Telescope (CFHT), were used to obtain high acquisition rates and signal-to-noise ratios. The light curves were also used to characterize the Q1R ring (radial profiles and orbital elements). Quaoar's elliptical fit to the occultation chords yields the limb with an apparent semi-major axis of 579.5+/-4.0km, apparent oblateness of 0.12+/-0.01, and area-equivalent radius of 543+/-2km. Quaoar's limb orientation is consistent with Q1R and Weywot orbiting in Quaoar's equatorial plane. The orbital radius of Q1R is refined to a value of 4057+/-6km. The radial opacity profile of the more opaque ring profile follows a Lorentzian shape that extends over 60 km, with a full width at half maximum (FWHM) of ~5km and a peak normal optical depth of 0.4. Besides the secondary events related to the already reported rings, new secondary events detected during the August 2022 occultation in three different data sets are consistent with another ring around Quaoar with a radius of 2520+/-20km, assuming the ring is circular and co-planar with Q1R. This new ring has a typical width of 10km and a normal optical depth of ~0.004. Just as Q1R, it also lies outside Quaoar's classical Roche limit.

Identifier
DOI http://doi.org/10.26093/cds/vizier.36739004
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/A+A/673/L4
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/673/L4
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/673/L4
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/A+A/673/L4
Provenance
Creator Pereira C.L.; Sicardy B.; Morgado B.E.; Braga-Ribas F.,Fernandez-Valenzuela E.; Souami D.; Holler B.J.; Boufleur R.C.; Margoti G.,Assafin M.; Ortiz J.L.; Santos-Sanz P.; Epinat B.; Kervella P.; Desmars J.,Vieira-Martins R.; Kilic Y.; Gomes Junior A.R.; Camargo J.I.B.; Emilio M.,Vara-Lubiano M.; Kretlow M.; Albert L.; Alcock C.; Ball J.G.; Bender K.,Buie M.W.; Butterfield K.; Camarca M.; Castro-Chacon J.H.; Dunford R.,Fisher R.S.; Gamble D.; Geary J.C.; Gnilka C.L.; Green K.D.; Hartman Z.D.,Huang C.-K.; Januszewski H.; Johnston J.; Kagitani M.; Kamin R.,Kavelaars J.J.; Keller J.M.; de Kleer K.R.; Lehner M.J.; Luken A.,Marchis F.; Marlin T.; McGregor K.; Nikitin V.; Nolthenius R.; Patrick C.,Redfield S.; Rengstorf A.W.; Reyes-Ruiz M.; Seccull T.; Skrutskie M.F.,Smith A.B.; Sproul M.; Stephens A.W.; Szentgyorgyi A.; Sanchez-Sanjuan S.,Tatsumi E.; Verbiscer A.; Wang S.-Y.; Yoshida F.; Young R.; Zhang Z.-W.
Publisher CDS
Publication Year 2023
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Natural Sciences; Observational Astronomy; Physics; Solar System Astronomy