J/MNRAS/489/574ivo://CDS.VizieR/J/MNRAS/489/574doi:10.26093/cds/vizier.74890574CDSTobinW.BarnesS.I.PerssonS.PollardK.R.2024-08-20T20:13:21Z2019-09-11T12:11:50ZCDS support team

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

cds-question@unistra.frvariable-starsspectroscopyWe present spectroscopy with resolution R~33000 of the circumstellar CaII H & K absorptions in the star beta Pictoris during 1997 and 1998. From 1997 April onwards, both lines were observed simultaneously. A total of 688 spectra were obtained on 95 nights in order to characterize the lines' behaviour. Near-continuous Falling Evaporating Body (FEB) variable absorption activity was seen, including additional strong, blue-shifted features besides the one on 1997 June 19-20 already reported by others. Temporal coverage is more even than in the HARPS spectra from 2004-11 that have been analysed for FEB orbital parameters via a model of FEB evaporation. Our observations likely encompass the 1997-98 Hill-sphere transit by beta Pic b, but we have found no clear signature of transiting material. Lower-velocity FEB absorptions tend to be deeper, narrower and longer lived, in confirmation of earlier studies. The ratio of line strengths for one absorption on 1998 November 27 is evocative of the variations expected for a single FEB making a transit perpendicular to the stellar rotation axis. Analysis with the evaporation model produces similar distributions of orbital parameters to those obtained from the HARPS observations, but when the derived orbital parameters are fed into a model based solely on gravitational dynamics of point masses, the predicted FEB accelerations do not agree with observed values. More sophisticated modelling is called for. There is no convincing intrinsic variation in the central circumstellar absorption such as might be expected if an HI ring is responsible for the confinement of circumstellar Ca^+^ ions. Our observations are available electronically for further analysis by others.2019MNRAS.489..574Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/489/574CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/299/557 : Light variations on Beta Pic (Lecavelier des Etangs+, 1995)J/A+A/542/A18 : {beta}Pic Harps radial velocity data (Lagrange+, 2012)J/A+A/607/A25 : beta Pic HARPS spectrum (Vidal-Madjar+, 2017)J/A+A/627/A28 : beta Pic BRITE, bRing, SMEI light curves (Zwintz+, 2019)J/ApJ/823/108 : A dust model for bet Pic from 0.58 to 870um (Ballering+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/489/574https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/489/574http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/489/574https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/489/574https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/489/574http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/489/574GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/MNRAS/489/574/table2Gaussian fits to the observed CaII absorptionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateUTC date of observation (YYYY-MM-DD)time.epoch;obsnullableTimeUTC time of mid observation (hh:mm)time.epochnullableHJDHeliocentric Julian Date of mid observationdtime.epochdoubleTexpExposure durationstime.duration;obs.exposureintHRVHeliocentric radial velocity of featurekm/sspect.dopplerVeloc;pos.heliocentricfloate_HRVUncertainty in heliocentric radial velocitykm/sstat.errorfloatFWHMFWHM of featurekm/sspect.line.widthfloate_FWHMUncertainty in FWHMkm/sstat.error;phys.angSizefloatpK? Relative depth of K absorptionphys.absorption.opticalDepthfloatnullablee_pK? Uncertainty in pKstat.errorfloatnullablepH? Relative depth of H absorptionphys.absorption.opticalDepthfloatnullablee_pH? Uncertainty in pHstat.errorfloatnullableEWK? Equivalent width of K absorption (m{AA})0.1pmspect.line.eqWidth;em.IR.Kintnullablee_EWK? Uncertainty in EWK (m{AA})0.1pmstat.errorintnullableEWH? Equivalent width of H absorption (m{AA})0.1pmspect.line.eqWidth;em.IR.Hintnullablee_EWH? Uncertainty in EWH (m{AA})0.1pmstat.errorintnullablequalFit quality (1)meta.code.qualcharJ/MNRAS/489/574/hkrf9798Reference spectra for observations made between 1997-04-21 and 1998-12-02recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLine[HK] "H" if CaII H, "K" if CaII Kmeta.id;spect.linecharlambdaAir wavelength ({AA})0.1nmem.wldoubleFluxFlux at wavelength lambda in arbitrary unitsphot.fluxfloatJ/MNRAS/489/574/figuresList of ps figuresrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFigNameName of the figure file in subdirectory figmeta.bib.figcharTitleTitle of the filemeta.title;meta.filecharFileNameName of the associated ascii file in subdirectory sp, if existmeta.id;meta.filechar