J/ApJ/839/97ivo://CDS.VizieR/J/ApJ/839/97doi:10.26093/cds/vizier.18390097CDSAndretta V.Giampapa M.S.Covino E.Reiners A.Beeck B.2018-03-12T09:11:08Z2018-01-12T13:04:40ZCDS support team

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

cds-question@unistra.frg-starsline-intensitiesSimultaneous, high-quality measurements of the neutral helium triplet features at 5876{AA} and 10830{AA} in a sample of solar-type stars are presented. The observations were made with ESO telescopes at the La Silla Paranal Observatory under program ID 088.D-0028(A) and MPG Utility Run for Fiber Extended-range Optical Spectrograph 088.A-9029(A). The equivalent widths of these features combined with chromospheric models are utilized to infer the fractional area coverage, or filling factor, of magnetic regions outside of spots. We find that the majority of the sample is characterized by filling factors less than unity. However, discrepancies occur among the coolest K-type and the warmest and most rapidly rotating F-type dwarf stars. We discuss these apparently anomalous results and find that in the case of K-type stars, they are an artifact of the application of chromospheric models best suited to the Sun than to stars with significantly lower Teff. The case of the F-type rapid rotators can be explained by the measurement uncertainties of the equivalent widths, but they may also be due to a non-magnetic heating component in their atmospheres. With the exceptions noted above, preliminary results suggest that the average heating rates in the active regions are the same from one star to the other, differing in the spatially integrated, observed level of activity due to the area coverage. Hence, differences in activity in this sample are mainly due to the filling factor of active regions.2017ApJ...839...97Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/839/97CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/50 : Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999)III/244 : Catalog of Stellar Rotational Velocities (Glebocki+ 2005)J/A+AS/132/155 : Main-sequence and subgiants ROSAT data (Huensch+ 1998)J/A+AS/135/319 : ROSAT data of Nearby Stars (Huensch+ 1999)J/A+A/397/147 : Activity-rotation relationship in stars (Pizzolato+ 2003)J/A+A/493/1099 : CaII HK emission in rapidly rotating stars (Schroeder+, 2009)J/A+A/511/A54 : Magnetic cycles & radial-velocity for 8 stars (Santos+, 2010)J/A+A/542/A116 : Rotation in A-F stars (Ammler-von Eiff+, 2012)J/A+A/557/L10 : Rotation periods of 12000 Kepler stars (Nielsen+, 2013)J/A+A/560/A4 : Rotation periods of active Kepler stars (Reinhold+, 2013)J/ApJS/211/24 : Rotation periods of Kepler MS stars (McQuillan+, 2014)J/A+A/579/A136 : HAT-P-36 and WASP-11/HAT-P-10 light curves (Mancini+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/839/97https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/839/97http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/839/97https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/839/97https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/839/97http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/839/97GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/839/97/table1 (Journal of observations for 41 HD stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/839/97/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/839/97/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/839/97/table1?GETtext/xml+votable180.050000true102.7076292-0.54088330.005555555555555556Cone search capability for table J/ApJ/839/97/ews (Helium equivalent width measurements and data for program stars (tables 3 and 4))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/839/97/ews?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/839/97/ews?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/839/97/ews?GETtext/xml+votable180.050000true102.7076292-0.54088330.0055555555555555566/17219 17425 20507 20587 20657 20701 21177 22120 22151 22759 23230 23369 23661 25231 26804 27006 33717 33849 34004 34577 35353 35753 35968 36664 36697 36850 37585 37680 37780 37816 38788 38936 39562 39953 40932 43688 46113 46529 46765 47598 48334https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/839/97?format=asciiOpticaldefaultJ/ApJ/839/97/table1Journal of observations for 41 HD starsm_HDHD componentmeta.code.multipcharNotesAdditional note(s) (3)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHDHD numbermeta.id;meta.mainintprimaryEWsDisplay the equivalent widths for this starmeta.ref.urlintnullableSpTypeMK spectral type (A0V to K2.5V) (1)src.spTypecharB-V[0.02/1] The (B-V) color index (1)magphot.color;em.opt.B;em.opt.VfloatFEROSHour of FEROS start time; UT (2)time.epochCRIRES? Hour of CRIRES start time; UT (2)time.epochnullableNodPos[AB] CRIRES nodding positioninstr.setupcharH91Display data from the Bright star catalogue (Hoffleit+, 1991, V/50) if anymeta.ref.urlintnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/ApJ/839/97/ewsHelium equivalent width measurements and data for program stars (tables 3 and 4)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSelmeta.codecharHDHD numbermeta.id;meta.mainintm_HDHD componentmeta.code.multipcharNobsNumber of spectroscopic observations for this starmeta.numberintnullableB-V[0.3/1] B-V color indexmagphot.color;em.opt.B;em.opt.Vfloatvsini[1/118] Rotational velocity (1)km/sphys.veloc.rotatfloatlogLx[26/30] Log of X-ray luminosity (2)log(1e-07W)phys.luminosity;em.X-rayfloatWHeI5876[3/77] HeI{lambda}5876 equivalent width1e-13mspect.line.eqWidthfloate_WHeI5876[1/7] WHeI5876 uncertainty1e-13mstat.errorfloatWHeI5876c[3/65] Corrected HeI{lambda}5876 equivalent width1e-13mspect.line.eqWidthfloate_WHeI5876c[1/8] WHeI5876c uncertainty1e-13mstat.errorfloatWHeI5876b[1/13]? Undetected stellar blends in the line profile1e-13mspect.line.eqWidthfloatnullablee_WHeI5876b[0.7/3]? WHeI5876b uncertainty1e-13mstat.errorfloatnullableW10830[51/410]? HeI{lambda}10830 equivalent width1e-13mspect.line.eqWidthfloatnullablee_W10830[1/21]? W10830 uncertainty1e-13mstat.errorfloatnullableW10829[12/70]? HeI{lambda}10829.1 equivalent width1e-13mspect.line.eqWidthfloatnullablee_W10829[1/16]? W10829 uncertainty1e-13mstat.errorfloatnullablef(C)[0.1/1]? Filling factor f for the C serie of models derived from Equation 1 (3)stat.fit.paramfloatnullablee_f(C)[0.03/0.2]? f(C) uncertaintystat.errorfloatnullablef(C-np)[0.1/1]? Filling factor f for the C-np serie of models derived from Equation 1 (3)stat.fit.paramfloatnullablee_f(C-np)[0.02/0.2]? f(C-np) uncertaintystat.errorfloatnullablefmin[0.03/1]? The minimum filling factor (4)stat.fit.paramfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main