J/A+AS/128/29 J/A+AS/128/29 X-ray/optical observations of A8-G2V stars A J M Piters J Van Paradijs J H M M Schmitt Astron. Astrophys. Suppl. Ser. 128 29 1998 1998A&AS..128...29P Effective temperatures Photometry, VBLUW Stars, dwarfs X-ray sources stars: activity stars: fundamental parameters X-rays: stars Table 1 lists the sample of 173 stars observed for this study. They are selected from the Bright Star Catalogue (Cat. <V/50>), with the following selection criteria: - Spectral type between A8 and G2; no spectral peculiarities noted; not double in spectral type classification (e.g., HR 32 with spectral type F2V+F6V is excluded); - Luminosity class V; - Right ascension between 0h and 2h, or between 14h and 24 h, declination south of +10 degrees (defining the region on the sky visible during the appointed observation times); - Binaries for which both components occurred in the BSC are excluded, if the separation is less than 10". Not listed are five stars for which no (Walraven photometric and ROSAT X-ray) data are available. These are HR 591, HR 5542, HR 6593, HR 8245 and HR 8735. Table 2 lists the Walraven photometric (VBLUW) data for all but four stars from Table 1. Also listed in Table 2 are the effective temperature, surface gravity and the reddening, as derived from comparison with theoretical colours. Table 5 lists the ROSAT All Sky Survey data for all but 11 stars from Table 1. For a description of the Walraven photometric system, see e.g. <GCPD/11>

HR HR (Cat. <V/50>) number --- Note See Note number=1 A: No Walraven data available B: No ROSAT data available --- Type Spectral Type number=2 Data from HR (Cat. <V/50>) catalog --- Vmag Apparent visual Johnson V magnitude number=2 Data from HR (Cat. <V/50>) catalog mag B-V Johnson's B-V colour number=2 Data from HR (Cat. <V/50>) catalog mag HR HR number (as in table1) --- Note See Note number=1 *: Probably variable: standard deviation of the brightness or one of the Walraven colours is more than 4 times as large as the average standard deviation. --- VWmag visual (Walraven) magnitude V mag e_VWmag standard deviation in VWmag mag V-B Walraven colour V-B mag e_V-B Standard deviation in V-B mag B-U Walraven colour B-U mag e_B-U Standard deviation in B-U mag U-W Walraven colour U-W mag e_U-W Standard deviation in U-W mag B-L Walraven colour B-L mag e_B-L Standard deviation in B-L mag o_B-L Number of observations --- Teff Effective temperature K e_Teff Uncertainty in Teff number=2 If the uncertainties are not given, no consistent stellar parameters could be found by the method applied here (minimum chi-square larger than 10). K logg Logarithm of surface gravity cm/s2 e_logg Uncertainty in logg number=2 If the uncertainties are not given, no consistent stellar parameters could be found by the method applied here (minimum chi-square larger than 10). cm/s2 E(V-B) The reddening E(V-B) mag e_E(V-B) Uncertainty in E_V-B number=2 If the uncertainties are not given, no consistent stellar parameters could be found by the method applied here (minimum chi-square larger than 10). mag HR HR number (as in table1) --- Note See Note number=1 U: upper limit values for Count, logRx, logFx, and logLx; hardness ratio h and the uncertainties (E_h, e_h, E_logRx, e_logRx, E_logFx, e_logFx, E_logLx, and e_logLx-) are not given (left blank). --- Count X-ray count rate s-1 E_Count Positive uncertainty in Count s-1 e_Count Negative uncertainty in Count s-1 XHR Hardness ratio --- E_XHR Positive uncertainty in XHR --- e_XHR Negative uncertainty in XHR --- logCx Log of energy-conversion factor number=2 The unit of the energy-conversion factor C_X_ is: cm^2/ergs, so that f_X_ = r_s_ / C_X_ is the flux density in ergs/(sec.cm^2) received at the detector. [10+7cm2/J] E_logCx Positive uncertainty in logCx [10+7cm2/J] e_logCx Negative uncertainty in logCx [10+7cm2/J] lognH Logarithm of hydrogen column density [cm-2] e_lognH Uncertainty in lognH [cm-2] logRx Log of Normalized X-ray flux density number=3 log Rx = log f_X_ + 0.1(V_J_ + BC) + 4.574 (BC: bolometric correction) log Fx = log Rx + 4logTeff - 4.246 log Lx = log Fx + 2log(R*/R_{sun}_) + 22.784 --- E_logRx Positive uncertainty in logRx --- e_logRx Negative uncertainty in logRx --- logFx Log of X-ray surface flux density number=3 log Rx = log f_X_ + 0.1(V_J_ + BC) + 4.574 (BC: bolometric correction) log Fx = log Rx + 4logTeff - 4.246 log Lx = log Fx + 2log(R*/R_{sun}_) + 22.784 --- E_logFx Positive uncertainty in logFx --- e_logFx Negative uncertainty in logFx --- logLx Logarithmic X-ray luminosity number=3 log Rx = log f_X_ + 0.1(V_J_ + BC) + 4.574 (BC: bolometric correction) log Fx = log Rx + 4logTeff - 4.246 log Lx = log Fx + 2log(R*/R_{sun}_) + 22.784 --- E_logLx Positive uncertainty in logLx --- e_logLx Negative uncertainty in logLx --- Ankie Piters Astron. Inst., Amsterdam Patricia Bauer CDS 1997Sep09Ankie Piters <piters@knmi.nl> J_A+AS_128_29.xml