J/AJ/134/778 BVRI photometry of candidate subdwarfs (Marshall, 2007)
Mapping the local galactic halo.
I. Optical photometry of cool subdwarf candidates.
Marshall J.L.
<Astron. J., 134, 778-786 (2007)>
=2007AJ....134..778M 2007AJ....134..778M
ADC_Keywords: Photometry, UBVRI ; Stars, subdwarf
Keywords: Galaxy: halo - solar neighborhood - stars: late-type - subdwarfs
Abstract:
Optical (BVRI) photometric measurements of a sample of 564 candidate
cool subdwarfs in the nearby halo are presented. The stars generally
span the color range 0.4<(B-V)<1.8; hence, the sample is composed of
early F- through early M-type stars on the subdwarf sequence. The
sample is selected from the revised NLTT catalog of Gould and Salim
and Salim and Gould via a reduced proper motion diagram. The
photometry is precise and accurate; in particular, for stars with
9<V<13.5 the photometry is accurate to 0.013, 0.015, 0.012, and
0.013mag in V, B-V, V-R, and V-I, respectively. For stars with
13.5<V<16 the photometry is accurate to 0.022, 0.018, 0.013, and
0.018mag in the same bands.
Description:
Photometric observations were obtained at the Cerro-Tololo
Inter-American Observatory (CTIO) on the 0.9m telescope during 2003
and on the 1.0m telescope in 2004, and at the MDM Observatory 1.3m
telescope during 2003 and 2004.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 74 564 BVRI photometry of candidate subdwarfs
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See also:
I/98 : NLTT Catalogue (Luyten, 1979)
J/ApJ/582/1011 : Revised NLTT Catalog (Salim+, 2003)
J/AJ/98/1693 : UBVRI photometry of NLTT stars (Ryan 1989)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- NLTT The NLTT identification number
7- 8 I2 h RAh Hour of Right Ascension (J2000)
10- 11 I2 min RAm Minute of Right Ascension (J2000)
13- 16 F4.1 s RAs Second of Right Ascension (J2000)
18 A1 --- DE- Sign of the Declination (J2000)
19- 20 I2 deg DEd Degree of Declination (J2000)
22- 23 I2 arcmin DEm Arcminute of Declination (J2000)
25- 26 I2 arcsec DEs Arcsecond of Declination (J2000)
28- 33 F6.3 mag Vmag The V band magnitude
35- 39 F5.3 mag B-V The (B-V) color index
41- 45 F5.3 mag V-R The (V-R) color index
47- 51 F5.3 mag V-I The (V-I) color index
53- 57 F5.3 mag V-J The (V-J) color index
59- 64 F6.3 mag V-H The (V-H) color index
66- 70 F5.3 mag V-K The (V-K) color index
72 I1 --- o_NLTT Number of observations of NLTT
74 I1 --- n_NLTT [1/2]? Possible variability (1)
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Note (1): Note on NLTT as follows:
1 = Star may be variable or have large photometric errors, due to
large standard deviation (>0.08mag) between multiple measurements
2 = Star may be variable or have large photometric errors, due to
large discrepancy with Hipparcos photometry
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History:
* 10-Nov-2009: From electronic version of the journal
* 01-Feb-2010: Declination sign corrected for NLLT 46798
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 30-Sep-2009