J/A+A/619/A127ivo://CDS.VizieR/J/A+A/619/A127doi:10.26093/cds/vizier.36190127CDSBiver N.Bockelee-Morvan D.Paubert G.Moreno R.Crovisier J.,Boissier J.Bertrand E.Boussier H.Kugel F.McKay A.Dello Russo N.,DiSanti M.A.2019-11-04T14:39:06Z2018-11-14T08:13:16ZCDS support team

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

cds-question@unistra.frcometsradio-astronomyco-line-emissionspectroscopychemical-abundancesWe present a multi-wavelength study of comet C/2016 R2 (PanSTARRS). This comet was observed on 23-24 January 2018 with the IRAM 30m telescope, and in January to March 2018 with the Nancay radio telescope. Visible spectroscopy was performed in December 2017 and February 2018 with small amateur telescopes. We report on measurements of CO, CH_3_OH, H_2_CO and HCN production rates, and on the determination of the N2/CO abundance ratio. Several other species, especially OH, were searched for but not detected. The inferred relative abundances, including upper limits for sulfur species, are compared to those measured in other comets at about the same heliocentric distance of ~2.8AU. The coma composition of comet C/2016 R2 is very different from all other comets observed so far, being rich in N2 and CO and dust poor. This suggests that this comet might belong to a very rare group of comets formed beyond the N_2_ ice line. Alternatively, comet C/2016 R2 (PanSTARRS) could be the fragment of a large and differentiated transneptunian object, with properties characteristic of volatile-enriched layers.2018A&A...619A.127Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/619/A127CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/619/A127https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/619/A127http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/619/A127https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/619/A127https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/619/A127http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/619/A127GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/619/A127/list (List of fits spectra)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/619/A127/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/619/A127/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/619/A127/list?GETtext/xml+votable180.050000true61.0643821.131940.0055555555555555566/370https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/619/A127?format=asciiRadiodefaultJ/A+A/619/A127/listList of fits spectrarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainNxNumber of pixels along X-axismeta.numberintObs.DateObservation date (YYYY/MM/DDThh:mm:ss.sss)stime.epoch;obsnullablebFreqLower value of frequency intervalHzem.freq;stat.mindoubleBFreqUpper value of frequency intervalHzem.freq;stat.maxdoubledFreqFrequency resolutionHzspect.resolutiondoublesizeSize of FITS fileKibytephys.size;meta.fitsintspShow the spectrummeta.ref.urlcharFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitscharComCommentsmeta.notechar