J/A+A/639/A11ivo://CDS.VizieR/J/A+A/639/A11doi:10.26093/cds/vizier.36390011CDSRebollido I.Eiroa C.Montesinos B.Maldonado J.Villaver E.Absil O.,Bayo A.Canovas H.Carmona A.Chen C.Ertel S.Henning T.,Iglesias D.P.Launhardt R.Liseau R.Meeus G.Moor A.Mora A.,Olofsson J.Rauw G.Riviere-Marichalar P.2020-10-02T11:26:42Z2020-07-01T07:31:53ZCDS support team

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

cds-question@unistra.frsolar-systemcometsspectroscopyWhile exoplanets are now routinely detected, the detection of small bodies in extrasolar systems remains challenging. Since the discovery of sporadic events, which are interpreted to be exocomets (falling evaporating bodies) around beta Pic in the early 1980s, Monly 20 stars have been reported to host exocomet-like events. We aim to expand the sample of known exocomet-host stars, as well as to monitor the hot-gas environment around stars with previously known exocometary activity. We have obtained high-resolution optical spectra of a heterogeneous sample of 117 main-sequence stars in the spectral type range from B8 to G8. The data were collected in 14 observing campaigns over the course of two years from both hemispheres. We analysed the CaII K&H and NaI D lines in order to search for non-photospheric absorptions that originated in the circumstellar environment and for variable events that could be caused by the outgassing of exocomet-like bodies. We detected non-photospheric absorptions towards 50% of the sample, thus attributing a circumstellar origin to half of the detections (i.e. 26% of the sample). Hot circumstellar gas was detected in the metallic lines inspected via narrow stable absorptions and/or variable blue- and red-shifted absorption events. Such variable events were found in 18 stars in the CaII and/or NaI lines; six of them are reported in the context of this work for the first time. In some cases, the variations we report in the CaII K line are similar to those observed in beta^L Pic. While we do not find a significant trend in the age or location of the stars, we do find that the probability of finding CS gas in stars with larger vsini is higher. We also find a weak trend with the presence of near-infrared excess and with anomalous (lambda Boo-like) abundances, but this would require confirmation by expanding the sample.2020A&A...639A..11Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/639/A11CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/639/A11https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/639/A11http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/639/A11https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/639/A11https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/639/A11http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/639/A11GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/639/A11/stars (List of studied stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/639/A11/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/639/A11/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/639/A11/stars?GETtext/xml+votable180.050000true1.4689167-41.75305560.005555555555555556Cone search capability for table J/A+A/639/A11/list (List of spectra)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/639/A11/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/639/A11/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/639/A11/list?GETtext/xml+votable180.050000true1.4689167-41.7530560.0055555555555555566/934 1771 1885 2317 2591 4277 4924 6082 6211 8687 9458 9875 10695 11031 11732 11946 12915 13054 13313 13646 13723 15583 15621 16606 17156 17421 17425 17887 19329 19584 19817 20658 21083 21285 21386 21388 22511 22773 23190 23376 23408 23502 23557 24277 24571 24796 25015 25056 26929 27735 27884 28787 30467 30475 30543 30655 31078 31789 32087 32192 32466 33340 33361 33976 34781 34823 34825 35474 35497 36130 36376 36487 36676 36907 37108 37810 37816 38929 38937 40223 41130 41361 42296 42910-42911 42991 43002 43095 43308 43351 43540 43677 43688 44069 44319 44321 44341 44352 44359 44368 44378 45247 45746 45835 45927 46084 46982 47205 47626 48905https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/639/A11?format=asciidefaultJ/A+A/639/A11/starsList of studied starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharRAJ2000Simbad right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Simbad declination (J2000)pos.eq.dec;meta.mainSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/639/A11/tablec1Observation logNoteNotemeta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharDate1Observation date (UT) (YYYYMMDDTHHMM)time.epoch;obscharInst1Instrumentmeta.id;instrcharDate2Observation date (UT) (YYYYMMDDTHHMM)time.epoch;obscharInst2Instrumentmeta.id;instrcharDate3Observation date (UT) (YYYYMMDDTHHMM)time.epoch;obscharInst3Instrumentmeta.id;instrcharJ/A+A/639/A11/listList of spectrarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharBand[BR-] Band for observations with Tigre telescopeinstr.bandpasscharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainObs.DateDate of observation, YYYY-MM-DDThh:mm:ssstime.epochnullableSizeSize of each fileKibytephys.size;meta.fileintspShow the spectrummeta.ref.urlcharFileNameName of the spectrum in subdirectory spmeta.idchar