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J/A+A/364/205       UBVy photometry of cool stars         (Cutispoto+, 2000)

Photometric and spectroscopic studies of cool stars discovered in EXOSAT X-ray images. IV. The northern hemisphere sample. Cutispoto G., Pastori L., Guerrero A., Tagliaferri G., Messina S., Rodono M., de Medeiros J.R. <Astron. Astrophys. 364, 205 (2000)> =2000A&A...364..205C
ADC_Keywords: Photometry, UBV ; Stars, late-type ; X-ray sources ; Radial velocities Keywords: techniques: photometric - techniques: spectroscopic - stars: abundances - stars: late-type - stars: variables: general - X-rays: stars Abstract: We present high-precision photometry, high- and medium-resolution spectroscopy for a sample of 32 stars likely to be the optical counterparts of X-ray sources serendipitously detected by the EXOSAT satellite. Using also recent results from the Hipparcos satellite, we infer spectral types, compute X-ray luminosities and Li abundances and investigate the single or binary nature of the sample stars. We found eleven new variable stars, whose photometric periods fall in the 1.2-27.5 day range, for most of which the optical variability is consistent with the presence of photospheric cool spots. For our sample of X-ray selected stars we confirm the existence of a strong correlation between the stellar rotation rate and the level of activity, and also between the X-ray and bolometric luminosities. Two stars in our sample are likely to be pre-main sequence objects, one is likely to be a previously unknown M-type star within 25pc. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file stars.dat 60 33 Star positions and magnitudes (from Simbad) ubvmag.dat 44 632 Complete UBV data set ymag.dat 45 118 Complete y-band data set table2.dat 95 32 Summary of stellar data table3.dat 45 17 Radial velocities tables.tex 79 142 LaTeX version of tables 2 & 3
See also: J/A+AS/115/41 : UBV(RI)c photometry of cool stars. (Cutispoto, 1996) Byte-by-byte Description of file: stars.dat
Bytes Format Units Label Explanations
1- 19 A19 --- Name Object name 21- 22 I2 h RAh Right ascension (J2000.0) 24- 25 I2 min RAm Right ascension (J2000.0) 27- 30 F4.1 s RAs Right ascension (J2000.0) 32 A1 --- DE- Declination sign (J2000.0) 33- 34 I2 deg DEd Declination (J2000.0) 36- 37 I2 arcmin DEm Declination (J2000.0) 39- 40 I2 arcsec DEs Declination (J2000.0) 44- 48 F5.2 mag Bmag ? B magnitude 50- 54 F5.2 mag Vmag ? V magnitude 56- 60 A5 --- SpType Spectral type
Byte-by-byte Description of file: ubvmag.dat
Bytes Format Units Label Explanations
1- 10 A10 --- Name Star name 12- 23 F12.4 d HJD Heliocentric Julian Day 25- 30 F6.3 mag Vmag V-band magnitude 32- 37 F6.3 mag B-V ?=9.999 B-V colour index 39- 44 F6.3 mag U-B ?=9.999 U-B colour index
Byte-by-byte Description of file: ymag.dat
Bytes Format Units Label Explanations
1- 19 A19 --- Name Star name 21- 32 F12.4 d HJD Heliocentric Julian Day 34- 39 F6.3 mag ymag Stromgren y-band star-comparison differential magnitude in the instrumental system 41- 45 F5.3 mag e_ymag rms uncertainty on ymag
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 19 A19 --- Name Star name 20 A1 --- n_Name [*] *: faint stars whose spectral types were evaluated from photographic plates data 22- 26 F5.2 mag Vmag V-band magnitude 27 A1 --- u_Vmag Uncertainty flag on Vmag 29- 44 A16 --- SpType spectral type inferred by us 45 A1 --- n_SpType [2] Note on SpType (1) 47- 49 I3 pc Dist Trigonometric or photometric (n_Dist = ":") distance 50 A1 --- n_Dist [:] ':' for photometric distance 52 A1 --- l_EWLi Limit flag on EWLi 53- 55 I3 0.1pm EWLi ? Li I 6708 equivalent width 57 A1 --- n_EWLi [yn 1] Note on EWLI (1) 59- 60 A2 --- Halpha [ae pf] H alpha line detection flag (1) 62- 63 A2 --- CaII [ae ?] Ca II H&K lines detection flag (1) 65 A1 --- l_Per Limit flag on Per 66- 70 F5.2 d Per ? Period of photometric variability 71 A1 --- u_Per [?] Uncertainty flag on Pper 73- 74 I2 km/s vsini ? Rotational velocity 75 A1 --- u_vsini Uncertainty flag on vsini 76 A1 --- n_vsini [1/3] Note on vsini 78- 81 F4.1 [10+23W] logLX ? log of X-ray luminosity (in 1030erg/s) from the ROSAT PSPC 83- 86 F4.1 [10+23W] logLXe ? log of X-ray luminosity (in 1030erg/s) from the EXOSAT CMA 88 A1 --- l_logALi Limit flag on logALi 89- 93 F5.2 --- logALi ? Li abundance in logarithmic scale (H abundance = 12) 94 A1 --- n_logALi [1] Note on logALi (1)
Note (1): Flags and notes: n: line not detectable y: line detectable a: absorption line pf: line partially filled-in by emission f: line filled-in by emission e: emission line 1: SB2 system, Li EW = 55 mÅ for both components, vsini = 12 and 7km/s, ALi = 2.7 and 2.6; 2: visual binary, both stars are constituted by M1V + M3:V components 3: SB 2, vsini = 50: and 30: km/s
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 10 A10 --- Name Star name 12- 23 F12.4 d HJD Heliocentric Julian Day 25- 29 F5.1 km/s RV Radial velocity value 31- 33 F3.1 km/s e_RV rms uncertainty on RV 35- 36 I2 --- o_RV Number of lines used for RV computation 38- 45 A8 --- SR Spectral region, Li (= Li I 6708) or Halpha
Acknowledgements: Giuseppe Cutispoto History: 31-Jan-2001: Positions of EXO sources corrected in file stars.dat References: Cutispoto at al., Paper I 1991A&AS...87..233C Tagliaferri et al., Paper II 1994A&A...285..272T Cutispoto et al., Paper III 1996A&AS..115...41C, Cat. J/A+AS/115/41
(End) Patricia Bauer [CDS] 18-Dec-2000
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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