J/A+A/317/689 Hot subdwarfs proper motions (Thejll+ 1997)
Proper motion of the hot subdwarfs. The kinematic population
membership of the SdB
Thejll P., Flynn C., Williamson R., Saffer R.
<Astron. Astrophys. 317, 689 (1997)>
=1997A&A...317..689T 1997A&A...317..689T
ADC_Keywords: Stars, subdwarf ; Proper motions
Keywords: astrometry - stars: subdwarf - fundamental parameters -
Galaxy: stellar content
Description:
We report on first results from an ongoing program to measure and
analyze proper motions for hot subdwarf and white dwarf stars, with
the aim of determining to which stellar population sdB stars (in the V
magnitude range 10.5 to 14.5) belong. Ours is the largest sample of
hot subdwarf proper motions measured to date. Our kinematic analysis
suggests that the parent population of these hydrogen-rich sdB stars
is as old or older than the old disk. We measure the absolute
magnitude of the sdB in the field as MV=4.5, providing independent
confirmation of absolute V magnitude estimates for these stars from
clusters and spectroscopic analyses. Provided it can be shown that the
sdO stars evolve from the sdB, then the sdO absolute V magnitude
distribution is about 1 magnitude brighter than for the sdB, and 1
magnitude wider.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
sd.dat 96 138 Astrometric results for the hot subdwarfs
(table4 to 9 of the paper)
wd.dat 80 42 White dwarf astrometric results from the
AC/CAMC and the POSS/GSC efforts
(table10 & 11 of the paper)
tables.tex 79 532 LaTeX version of the tables
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Byte-by-byte Description of file: sd.dat
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Bytes Format Units Label Explanations
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2- 3 I2 h RAh Right ascension J2000
5- 6 I2 min RAm Right ascension J2000
8- 12 F5.2 s RAs Right ascension J2000
14 A1 --- DE- Declination sign
15- 16 I2 deg DEd Declination J2000
18- 19 I2 arcmin DEm Declination J2000
21- 25 F5.2 arcsec DEs Declination J2000
27- 31 F5.4 arcsec/yr pm1 Proper motion from the AC/CAMC system
33- 37 F5.4 arcsec/yr e_pm1 rms uncertainty on pm1
39- 41 I3 deg pmPA1 Position angle for proper motion from the
AC/CAMC system (counted positive east of north)
45- 46 I2 deg e_pmPA1 rms uncertainty on PA1
50- 53 F4.3 arcsec/yr pm2 ? Proper motion from the POSS/GSC system
56- 59 F4.3 arcsec/yr e_pm2 ? rms uncertainty on pm2
62- 64 I3 deg pmPA2 ? Position angle for proper motion from the
POSS/GSC system (positive east of north)
68- 69 I2 deg e_pmPA2 ? rms uncertainty on PA2
71- 96 A26 --- Note Note
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Byte-by-byte Description of file: wd.dat
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Bytes Format Units Label Explanations
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2- 3 I2 h RAh Right ascension J2000
5- 6 I2 min RAm Right ascension J2000
8- 12 F5.2 s RAs Right ascension J2000
14 A1 --- DE- Declination sign
15- 16 I2 deg DEd Declination J2000
18- 19 I2 arcmin DEm Declination J2000
21- 25 F5.2 arcsec DEs Declination J2000
27- 31 F5.4 arcsec/yr pm Proper motion
33- 37 F5.4 arcsec/yr e_pm rms uncertainty on pm
39- 41 I3 deg pmPA Position angle for proper motion
(counted positive east of north)
45- 46 I2 deg e_pmPA rms uncertainty on PA
50- 51 A2 --- Class WD Spectral class (1)
53- 73 A21 --- Name Various names for the star taken from the
McCook & Sion catalog. (2)
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Note (1): WD spectral class derived from positions and the WD catalog III/129
Note (2): PG and KPD refers to stars in Green et al. (1986ApJS...61..305G 1986ApJS...61..305G)
and Downes (1986ApJS...61..569D 1986ApJS...61..569D).
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Acknowledgements: Peter A. Thejll
References:
Downes R.A., 1986, ApJS 61, 569 =1986ApJS...61..569D 1986ApJS...61..569D
Green, R. F. et al., 1986, ApJS 61, 305 =1986ApJS...61..305G 1986ApJS...61..305G
McCook G.P. & Sion E.M., 1987, ApJS 65, 603 =Cat III/129
(End) Patricia Bauer [CDS] 01-Aug-1996