J/ApJS/266/41ivo://CDS.VizieR/J/ApJS/266/41doi:10.26093/cds/vizier/bb-8a-19CDSPal T.Khan I.Worthey G.Gregg M.D.Silva D.R.2026-08-03T07:25:04Z2023-10-26T14:11:20ZCDS support team

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

cds-question@unistra.frspectroscopyultraviolet-astronomymetallicityvisible-astronomybroad-band-photometryradial-velocityabsolute-magnitudeextinctionIn order to provide fundamental stellar spectra that extend into the UV, Hubble Space Telescope's Space Telescope Imaging Spectrograph targeted 556 stars via proposals GO9088, GO9786, GO10222, and GO13776. Exposures through three low-resolution gratings provide wavelength coverage from 0.2<{lambda}<1{mu}m at {lambda}/{Delta}{lambda}~1000. The UV grating (G230LB) scatters red light that results in unwanted signal, especially in cool stars. We applied scattered-light corrections and flux corrections arising from pointing errors relative to the center of the 0.2" slit based on Worthey et al. We present 513 fully reduced stellar spectra, fluxed, dereddened, and cross correlated to zero velocity. Because of the broad spectral range, we can simultaneously study H{alpha} and MgII{lambda}2800, indicators of chromospheric activity. Their behaviors are decoupled. Besides three cool dwarfs and one giant with mild flares in H{alpha}, only Be stars show strong H{alpha} emission. Mg2800 emission, however, strongly anticorrelates with temperature such that warm stars show absorption and stars cooler than 5000K universally show chromospheric emission regardless of dwarf/giant status or metallicity. Transformed to Mg2800 flux emerging from the stellar surface, we find a correlation with temperature with approximately symmetric astrophysical scatter. Previous work had indicated a basal level with asymmetric scatter to strong values. The discrepancy is primarily due to our improved treatment of extinction. We confirm statistically significant time variability in Mg2800 strength for one star.2023ApJS..266...41Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/266/41CatalogResearchIsServedByTAP VizieR generic servicerelated-toIII/92 : A Library of Stellar Spectra (Jacoby+ 1984)J/ApJS/82/197 : Mean UV Spectra of Stellar Groups (Fanelli+ 1992)J/ApJS/94/687 : Old stellar populations. V. (Worthey+, 1994)J/A+AS/125/229 : A standard stellar library (Lejeune+ 1997)J/A+AS/130/65 : A standard stellar library. II. (Lejeune+ 1998)J/MNRAS/298/525 : Stellar evolution models for Z = 0.0001 to 0.03 (Pols+ 1998)J/A+AS/139/555 : Catalogue and Bibliography of UV Cet stars (Gershberg+ 1999)J/A+A/374/1085 : Mg II K line Wilson-Bappu relationship (Cassatella+, 2001)J/ApJS/152/251 : Indo-US library of coude feed stellar sp. (Valdes+, 2004)J/MNRAS/371/703 : MILES library of empirical spectra (Sanchez-Blazquez+, 2006)J/ApJ/657/1046 : Synthetic Mid-UV sp. indices of stars (Chavez+, 2007)J/A+A/469/309 : Activity in late-type stars (Cincunegui+, 2007)J/A+A/483/903 : Mount Wilson index for F-K stars (Buccino+, 2008)J/MNRAS/414/418 : Chromospheric Mg II h+k flux of evolved stars (Perez+, 2011)J/ApJS/193/1 : UBVRIJHK color-temperature calibration (Worthey+, 2011)J/A+A/525/A71 : Atmospheric parameters for 1273 stars (Wu+, 2011)J/A+A/538/A143 : Atmospheric param. of stars for UV models (Koleva+, 2012)J/A+A/549/A129 : Equivalent widths of cool stars (Cesetti+, 2013)J/A+A/551/L8 : Chromospheric activity of field stars (Pace, 2013)J/A+A/566/A66 : Correlation of logR'HK with logIHa (Gomes da Silva+, 2014)J/A+A/561/A36 : The LickX Spectra library (Worthey+, 2014)J/A+A/615/A115 : HST Hot Star Library (Khan+, 2018)J/MNRAS/514/4300 : Late-type dwarfs logR'HK and magnetic fields (Brown+, 2022)J/A+A/658/A57 : F-G-K stars activity indicators (Meunier+, 2022)J/A+A/660/A34 : X-Shooter Spectral Library (XSL). DR3 (Verro+, 2022)http://astro.wsu.edu/hststarlib/ : HST/STIS stellar spectral library homepagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/266/41https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/266/41http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/266/41https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/266/41https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/266/41http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/266/41GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapUVOpticaldefaultJ/ApJS/266/41/table3Stellar metadataONameHeader identifiermeta.idcharTeff[2377/32902] Effective temperatureKphys.temperature.effectiveintNameSimbad identifiermeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlogg[-0.3/5.34] log surface gravitylog(cm.s**-2)phys.gravityfloat[Fe/H][-2.11/1] Metallicitylog(Sun)phys.abund.ZfloatBmag[1.29/13]? Apparent B band Vega magnitudemagphot.mag;em.opt.BfloatnullableVmag[1.19/14]? Apparent V band Vega magnitudemagphot.mag;em.opt.Vfloatnullableplx[0.25/768.5] Simbad parallaxmaspos.parallax.trigfloatVMag[-9.81/15.6]? Absolute V band Vega magnitudemagphys.magAbsfloatnullabledSlit[-1/1.1] Slit off-center correctionpixstat.errorfloatRVel[-389/340] Radial velocitykm/sphys.veloc;pos.heliocentricfloatK0[0/4843] Scattered light count rate at 2000{AA}; ADUcount**-1phot.count;em.UVfloatAv[0/3.1] The V band extinctionmagphys.absorptionfloatf_Av[1/3] Note on Av (1)meta.codeintMg2800[-5.8/2.5]? The MgII 2800 indexmagspect.indexfloatnullableHa[-0.54/0.4]? The H{alpha} indexmagspect.indexfloatnullableHb[-0.5/0.43]? The H{beta} indexmagspect.indexfloatnullableNoteNote(s) for objects noted in Section 5.2 (2)meta.notecharfitsDownload the FITS filemeta.ref.urlcharSpInteractive spectrum plotmeta.ref.urlchar