J/ApJ/348/557 J/ApJ/348/557 X-ray studies of stars in the Pleiades G Micela S Sciortino G S Vaiana F R Harnden R Rosner J H M M Schmitt Astrophys. J. 348 557 1990 1990ApJ...348..557M J/ApJ/315/687 : X-Ray emission from solar-type stars: F and G J/ApJ/348/253 : Einstein Survey of Late-type Giant and Supergiant Stars J/ApJ/325/798 : Einstein Survey of Hyades-cluster Region J/ApJ/351/492 : X-ray Emission in the Ursa Major Stream Ahmed, F., Lawrence, L., and Reddish, V.C. 1965, Pub. Roy. Obs. Edinburgh, Vol. 1, No. 7. Hertzsprung, E. 1947, Ann. Leiden Obs., Vol. 19, Pt. 1A. McCarthy, M.F. and Treanor, P.S. 1964, Ric. Astr., 6, 535. Seward, F.D. and Martenis, P. 1986, Einstein Observatory Catalog of Observations (the "Yellow Book"; 5th ed.; Cambridge: Harvard-Smithsonian Center for Astrophysics). van Leeuween, F. 1983, Ph.D. thesis, Leiden. Clusters, open Stars, emission X-ray sources open clusters and associations: individual (Pleiades) stars: rotation stars: X-rays Coronal X-ray emission of the Pleiades stars is investigated, and maximum likelihood, integral X-ray luminosity functions are computed for Pleiades members in selected color-index ranges. A detailed search is conducted for long-term variability in the X-ray emission of those stars observed more than once. An overall comparison of the survey results with those of previous surveys confirms the ubiquity of X-ray emission in the Pleiades cluster stars and its higher rate of emission with respect to older stars. It is found that the X-ray emission from dA and early dF stars cannot be proven to be dissimilar to that of Hyades and field stars of the same spectral type. The Pleiades cluster members show a real rise of the X-ray luminosity from dA stars to early dF stars. X-ray emission for the young, solar-like Pleiades stars is about two orders of magnitude more intense than for the nearby solar-like stars.

Einstein

Name Star name number=1 This column gives the star name(s), coded according to the following conventions: A: Asiago observatory flare stars ALR: Ahmed, Lawrence and Reddish (1965) B: Byurakan observatory flare stars Hz: Hertzsprung (1947) JRS: Stauffer (1984ApJ...280..189S) MT: McCarthy and Treanor (1964) (1964RA......6..535M) P: Pels (Quoted in van Leeuween, 1983) van Leeuween, F. 1983, Ph.D. thesis, Leiden. T: Tonantzintla flare stars (Cat.<II/131>) VM: VanMaanen (1945ApJ...102...26V) --- RAh Right Ascension (B1950) (hour) h RAm Right Ascension (B1950) (min) min RAs Right Ascension (B1950) (sec) s DE- Declination sign (B1950) --- DEd Declination (B1950) (deg) deg DEm Declination (B1950) (arcmin) arcmin DEs Declination (B1950) (arcsec) arcsec Vmag Apparent Visual magnitude number=2 These columns give the following optical properties of the stars: the apparent visual magnitude, the B-V color index, the spectral type, and the equatorial (rotational) velocity projected along the line of sight. Optical properties are taken from the literature (see references below). If a the spectral property or rotational velocity is not known, a '...' appears as the entry in the column. mag r_Vmag Reference for visual magnitude number=3 These columns list the reference used to obtain Vmag, Sp, and Vsini. --- B-V B-V color index number=2 These columns give the following optical properties of the stars: the apparent visual magnitude, the B-V color index, the spectral type, and the equatorial (rotational) velocity projected along the line of sight. Optical properties are taken from the literature (see references below). If a the spectral property or rotational velocity is not known, a '...' appears as the entry in the column. mag Sp Spectral type number=2 These columns give the following optical properties of the stars: the apparent visual magnitude, the B-V color index, the spectral type, and the equatorial (rotational) velocity projected along the line of sight. Optical properties are taken from the literature (see references below). If a the spectral property or rotational velocity is not known, a '...' appears as the entry in the column. --- r_Sp Reference for spectral type number=3 These columns list the reference used to obtain Vmag, Sp, and Vsini. --- Vsini Equatorial (rotational) velocities along line of sight number=2 These columns give the following optical properties of the stars: the apparent visual magnitude, the B-V color index, the spectral type, and the equatorial (rotational) velocity projected along the line of sight. Optical properties are taken from the literature (see references below). If a the spectral property or rotational velocity is not known, a '...' appears as the entry in the column. km/s r_Vsini Reference for vsini Comma separated list number=3 These columns list the reference used to obtain Vmag, Sp, and Vsini. --- notes Notes on the source number=4 This column is for notes on the source. In particular, we have noted when we believe a star is variable (var.) or binary (bin). If there is no note on the source, a '...' appears as the entry in the column. --- f_Lx "1" if luminosity is an upper limit number=5 The "f_Lx" column is flagged with a "1" if the X-ray luminosity is an upper limit. Upper limits given are 3-sigma upper bounds for all members of the optical sample that fall within 2' of the position of an object from the Einstein Observatory master catalog (which includes ~60 different catalogs). The log of the X-ray luminosity from 0.16-4.0 keV is presented in the "lx" column and the corresponding error (by percentage) is listed in the "e_lx" column. If the luminosity is an upper limit, the uncertainty is listed as 0.000. --- Lx log of X-ray luminosity from 0.16-4.0 keV number=5 The "f_Lx" column is flagged with a "1" if the X-ray luminosity is an upper limit. Upper limits given are 3-sigma upper bounds for all members of the optical sample that fall within 2' of the position of an object from the Einstein Observatory master catalog (which includes ~60 different catalogs). The log of the X-ray luminosity from 0.16-4.0 keV is presented in the "lx" column and the corresponding error (by percentage) is listed in the "e_lx" column. If the luminosity is an upper limit, the uncertainty is listed as 0.000. [10-7W] e_Lx Percentage-error on X-ray luminosity number=5 The "f_Lx" column is flagged with a "1" if the X-ray luminosity is an upper limit. Upper limits given are 3-sigma upper bounds for all members of the optical sample that fall within 2' of the position of an object from the Einstein Observatory master catalog (which includes ~60 different catalogs). The log of the X-ray luminosity from 0.16-4.0 keV is presented in the "lx" column and the corresponding error (by percentage) is listed in the "e_lx" column. If the luminosity is an upper limit, the uncertainty is listed as 0.000. % flx_flg Flag indicating how flux was evaluated number=6 This column indicates how the X-ray flux is evaluated: MB: from the "Map" cell count rate LB: from the "Local" cell count rate WM: from a weighted mean, for sources observed more than once See the paper (1990ApJ...348..557M) for further details. --- reco Ribs and Edge Code flag number=7 This column is flagged "Y" if the X-ray luminosity is derived in the presence of potential source shadowing. Reco is a ribs and edge code, indicating that the source fell on or near the detector ribs or edges. The local detect algorithm uses a detection cell subdivided into nine central subcells (3x3) with a background frame (around the central cell) subdivided into 16 subcells. The reco value provides an estimate of the number of background and detection subcells potentially obscured and is nonzero whenever a source could have any of its central or frame subcells obscured. However, this approach necessarily employs simplifying assumptions regarding the shape and dimensions of the ribs, and it neglects spectral dependencies. Consequently, although a quantitative attempt is made to correct for such effects, the only completely reliable approach is to regard count rates for sources with nonzero reco values (flagged "Y" here) as indeterminate. See the paper (1990ApJ...348..557M) for more details. --- Seqno Sequence Number number=1 This column gives the Einstein "sequence" number of the field. The sequence number is a two to five digit number which uniquely identifies the observation. The numbers were assigned sequentially at the time of proposal submission. --- RAh Right Ascension (B1950) (hour) h RAm Right Ascension (B1950) (min) min RAs Right Ascension (B1950) (sec) s DE- Declination sign (B1950) --- DEd Declination (B1950) (deg) deg DEm Declination (B1950) (arcmin) arcmin DEs Declination (B1950) (arcsec) arcsec Date Observation Date number=2 These columns give the date of the observation and the original obs of the field. The obs listed is from the "Yellow Book" (Seward and Martenis, 1986). --- live Live Time number=3 This column gives the observation live time, in kiloseconds. The live time is the effective exposure time, a measure of the total time the detectors were able to gather data. It excludes intervals lost because of Earth occultation, because of passage through the South Atlantic Anomaly, or because of unacceptable aspect solution. The livetime has been corrected for detector dead time, a fractional correction for the time during which the detector is unable to record events because it is "processing" a prior event. ks Obs Original Einstein Observer number=2 These columns give the date of the observation and the original obs of the field. The obs listed is from the "Yellow Book" (Seward and Martenis, 1986). --- code reference code --- reftxt reference text --- Patricio Ortiz CDS 1999Mar31 UNKNOWN UNKNOWN Prepared from the tables available at the "ADS Catalogue Service" (CfA, Harvard-Smithsonian Center for Astrophysics, Cambrigde MA) J_ApJ_348_557.xml