CDROM/AJ/V105/P0226 Ursa Major Group (Soderblom & Mayor 1993) ================================================================================ Stellar Kinematic Groups. I. The Ursa Major Group David R. Soderblom & Michel Mayor <1993, AJ, 105, 226> =1993AJ....105..226S ================================================================================ Abstract: The Ursa Major Group (UMaG) is studied as a test case for the authenticity of Stellar Kinematic Groups, using Coravel radial velocities, recent compilations of astrometric data and new spectroscopic observations. Spectroscopic age indicators, particularly indices of the strength of chromospheric emission, are applied to solar-type candidate members of UMaG, and it is shown that stars that meet the spectroscopic criteria also have kinematics that agree better with the space motions of the nucleus of UMaG than does the starting sample as a whole. The primary limitation on the precision of kinematics is now parallaxes instead of radial velocities. These more restrictive kinematic criteria are then applied to other UMaG candidates and a list summarizing membership is presented. UMaG is also examined as a cluster, confirming its traditional age of 0.3 Gyr and a mean [Fe/H] of -0.08 +/- 0.09 for those stars most likely to be bona fide members. File Summary: -------------------------------------------------------------------------------- File Name Lrecl Records Explanations -------------------------------------------------------------------------------- table1.dat 76 14 Stellar kinematic groups table3.dat 68 35 Echelle spectroscopy of UMaG candidates table5.dat 98 49 Spectroscopic membership indicators for UMaG solar-type stars table7.dat 113 40 Kinematics of UMaG solar-type candidates table10.dat 80 27 Kinematics of additional UMaG candidates table11.dat 74 46 Summary of UMaG membership -------------------------------------------------------------------------------- Comments for file: table1.dat -------------------------------------------------------------------------------- Table 1 lists stellar kinematic groups that have been identified the solar neighborhood. The velocities in this table are generally those of the defining star, taken from Woolley et al. 1970 [R. Obs. Ann., No. 5], and are meant to be indicative, not definitive. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1-32 A32 --- Name Group name 33-37 I5 km/s VU U space velocity 38-42 I5 km/s VV V space velocity 43-47 I5 km/s VW W space velocity 48-49 2X --- --- Blank 50-76 A27 --- Ref *References -------------------------------------------------------------------------------- Notes for file: table1.dat -------------------------------------------------------------------------------- Ref: References for the kinematic data are as follows: Eggen 1958a, MNRAS, 118, 65 Eggen 1958b, MNRAS, 118, 154 Eggen 1958c, MNRAS, 118, 560 Eggen 1959a, Obs, 79, 88 Eggen 1959b, Obs, 79, 182 Eggen 1960b, MNRAS, 120, 563 Eggen 1964, R. Obs. Bull., No. 84 Eggen 1965c, Obs, 85, 191 Eggen 1969, PASP, 81, 553 Eggen 1971a, PASP, 83, 251 Eggen 1971b, PASP, 83, 271 Eggen 1975, PASP, 87, 37 Eggen 1978, ApJ, 222, 203 Eggen 1987, in The Galaxy, edited by G. Gilmore and B. Carswell (Reidel, Dordrecht), p. 211 Eggen and Sandage 1959, MNRAS, 119, 255 Roman 1949, ApJ 110, 205 Woolley, et al. 1970, R. Obs. Ann., No. 5 -------------------------------------------------------------------------------- Comments for file: table3.dat -------------------------------------------------------------------------------- Table 3 summarizes high-dispersion echelle spectra obtained for some of the Ursa Major Group (UMaG) candidates at the Lick Observatory. The printed paper and Soderblom et al. 1993 [ApJS, 85, 315] provide details of the observations and data reduction. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table3.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 8 A8 --- HD Henry Draper number 9-10 2X --- --- Blank 11 A1 --- l_vsini [< ] Limiting character for v sin i 12-15 F4.1 km/s vsini []? v sin i 16 1X --- --- Blank 17 A1 --- l_WHalp [< ] Limiting character for WHalp 18-21 F4.2 mA WHalp []? Equivalent width of Halpha line 22 1X --- --- Blank 23 A1 --- l_W8498 [< ] Limiting character for W8498 24-27 F4.2 mA W8498 []? Equivalent width of 8498 A feature 28 1X --- --- Blank 29 A1 --- l_W8542 [< ] Limiting character for W8542 30-33 F4.2 mA W8542 []? Equivalent width of 8542 A feature 34 1X --- --- Blank 35 A1 --- l_W8662 [< ] Limiting character for W8662 36-39 F4.2 mA W8662 []? Equivalent width of 8662 A feature 40-41 2X --- --- Blank 42 A1 --- l_RHalp [< ] Limiting character for RHalp 43-47 F5.2 --- RHalp *[]? Log chromospheric flux ratio for Halpha 48 A1 --- u_RHalp [: ] In one case for star HD 141003B 49 A1 --- l_R8498 [< ] Limiting character for R8498 50-54 F5.2 --- R8498 *[]? Log chrom. flux ratio for 8498 A feature 55 1X --- --- Blank 56 A1 --- l_R8542 [< ] Limiting character for R8542 57-61 F5.2 --- R8542 *[]? Log chrom. flux ratio for 8542 A feature 62 1X --- --- Blank 63 A1 --- l_R8662 [< ] Limiting character for R8662 64-68 F5.2 --- R8662 *Log of chrom. flux ratio for 8662 A feature -------------------------------------------------------------------------------- Notes for file: table3.dat -------------------------------------------------------------------------------- RHalp, R8498, R8542, R8662: The surface flux was divided by the star's bolometric flux to obtain the chromospheric flux ratios. -------------------------------------------------------------------------------- Comments for file: table5.dat -------------------------------------------------------------------------------- Table 5 lists the results of spectroscopic membership analysis of the UMaG solar-type stars. The table contains data for (a) probable spectroscopic members, (b) possible spectroscopic members, and (c) probable spectroscopic non-members. The three parts of the table are delimited by header records with the letters 'a', 'b', or 'c' in column 1. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table5.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1 A1 --- Delim *[abc ] Delimiter separating the three groups 2-7 A6 --- Woolley *Number in catalog of Woolley, et al. (1970) 8 1X --- --- Blank 9-16 A8 --- HD Henry Draper number 17 1X --- --- Blank 18-23 A6 --- HR Harvard Revised (HR) number 24 1X --- --- Blank 25-35 A11 --- Other Other name 36 1X --- --- Blank 37-40 A4 --- Sp *Spectral type 41-42 2X --- --- Blank 43-46 F4.2 mag B-V *[]? (B-V) color 47 A1 --- u_B-V Uncertainty flag for B-V, for HD 141003B only 48-52 I5 K Teff []? Effective temperature 53 A1 --- u_Teff Uncertainty flag for Teff 54 1X --- --- Blank 55 A1 --- l_Rprime *[