J/other/AstL/51.ivo://CDS.VizieR/J/other/AstL/51.536CDSKhamitov I.M.Bikmaev I.F.Gilfanov M.R.Sunyaev R.A.Gorbachev M.A.,Panarin S.S.Medvedev P.S.2026-05-04T07:43:19Z2026-04-21T14:49:35ZCDS support team

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

cds-question@unistra.fropen-star-clustersx-ray-sourcesUsing data from the all-sky X-ray survey with the eROSITA telescope onboard the SRG orbital observatory and the optical catalog of Blanco 1 cluster members constructed from Gaia data, we have investigated the X-ray emission from cluster stars. Of the 723 cluster members located in the eastern Galactic part of the sky, eROSITA detects X-ray emission from 110 stars, thereby increasing the number of known sources by more than a factor of 2. At the Blanco 1 distance (~234pc) the median eROSITA sensitivity in this sky region corresponds to a 0.3-2.3keV luminosity LX~1.1*10^29^erg/s, allowing more than 60% of the solar-type stars to be detected within the Blanco 1 tidal radius. For one source a strong (more than a factor of 10) X-ray variability on a time scale of six months has been recorded. This is a late-M star. The RX=log(LX/Lbol) distribution of Blanco 1 stars is bimodal. The left peak at RX_-4.2 is formed by FGK stars, while the right peak at RX~-3.1 consists predominantly of K and M stars. A comparison of the properties of X-ray sources in the similarly aged Blanco 1 and Pleiades clusters has shown a high level of consistency, pointing to a common evolutionary scenario for the X-ray activity of stars in these clusters.2025AstL...51..536Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/other/AstL/51.536CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)J/A+A/678/A75 : Young nearby open clusters members photometry (Zerjal+, 2023)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/other/AstL/51.536https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/other/AstL/51.536http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/other/AstL/51.536https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/other/AstL/51.536https://vizier.iucaa.in/viz-bin/votable?-source=J/other/AstL/51.536http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/other/AstL/51.536GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/other/AstL/51.536/table1 (Catalogue of SRG/eROSITA sources associated with Blanco 1)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/other/AstL/51.536/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/other/AstL/51.536/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/other/AstL/51.536/table1?GETtext/xml+votable180.050000true0.2399413-30.12331390.0055555555555555565/4122 6/16435 16444 16447 16481 16483 16494 16531-16533 16543 16565 16576-16577 16579 16584-16585 16608 16611https://cdsarc.cds.unistra.fr/viz-bin/moc/J/other/AstL/51.536?format=asciiX-raydefaultJ/other/AstL/51.536/table1Catalogue of SRG/eROSITA sources associated with Blanco 1recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSRGeDesignaton of SRGe+meta.id;meta.maincharGaiaDR3Designaton of GAIA DR3+ (1)meta.idRA_ICRSGaia DR3 right ascension (ICRS) at Ep=2016.0 (ra) (1)degpos.eq.ra;meta.mainDE_ICRSGaia DR3 declination (ICRS) at Ep=2016.0 (dec) (1)degpos.eq.dec;meta.mainGmagGAIA DR3 G-band mean magnitude (1)magphot.mag;em.optdoubler98eROSITA source position errorarcsecstat.error;posfloatsepSeparation between X-ray (eROSITA) and optical (GAIA DR3) positions of sourcearcsecpos.angDistancefloatNgaia[1/3] Number of GAIA DR3 sources within r98meta.numberintLXX-ray luminosity in 0.3-2.3keV band according to 4 eROSITA surveys (in 10^+29^erg/s unit)1e+22Wphys.luminosity;em.X-rayfloate_LX1-sigma error of X-ray luminosity in 0.3-2.3keV band according to 4 eROSITA surveys (in 10^+29^erg/s unit)1e+22Wstat.errorfloatlogRXLog of ratio X-ray in 0.3-2.3keV to bolometric luminosities (4)phys.luminosity;arith.ratiodoublef_Xvar[012] Flag on Xvar (2)meta.codecharXvar? Factor of X-ray variability (3)stat.fit.paramdoublenullableSpTypeSpectral type (4)src.spTypecharN6d[1/2] The number of Blanco 1 stars within r98meta.numberintbflag[0/1] Binarity parameter, 1 indicates the system with binaritymeta.codeint