II/277 UBVRI photometry of faint field stars (Skiff, 2007)
UBVRI photometry of faint field stars
Skiff B.A.
<Lowell Observatory (2007)>
=2007yCat.2277....0S 2007yCat.2277....0S
ADC_Keywords: Photometry, UBVRI ; Photometry, sequences
Description:
This file, originally prepared for the needs of the Lowell Observatory
Near-Earth Object Search (LONEOS), contains a rough working collection
of Johnson-Cousins UBVRI photometry assembled mainly from the
published literature or from publicly available datasets. The V-R and
V-I colors are all on the Cousins system. Most of the stars are
fainter than V=10.0; the median magnitude is V=13.9, and significant
numbers of stars are listed below 20mag. Besides several large
surveys, several hundred small sequences in the regions of variable
stars, star clusters, galaxies hosting supernovae, quasars, etc were
built by determining coordinates for the sequence stars using the
published finder charts. At minimum the data include V magnitudes and
at least one ordinary photometric color, most commonly B-V.
The data were collected for use in determining approximate photometric
zero-points in wide-field imaging, with external accuracy of 0.05 mag
or better. Though each dataset was vetted for consistency in magnitude
and colors, neither high accuracy nor high precision is guaranteed.
Obvious variable stars were omitted, but some unknown variables are
inevitably included. In any given field, it is advisable use all the
available stars for calibration rather than a single comparison.
Several large datasets are included. The Guide Star Photometric
Catalogue (GSPC, Lasker et al 1988, Cat. II/143) provides BV sequences
near the centers of all the Schmidt sky survey plates. At high
latitudes in the southern sky, additional data on the 5-degree Schmidt
grid were obtained by Platais et al (1998, Cat. I/277) that extend the
GSPC sequences to V≃16. More southern fields were observed by Demers
et al (1993A&AS...99..437D 1993A&AS...99..437D and 1993A&AS...99..461D 1993A&AS...99..461D); coordinates for
these stars have been determined for the first time. Nearly a thousand
high-quality sequences in the northern sky have been observed by
Henden, partly published in relation to work on cataclysmic variables
(e.g. Cat. J/PASP/107/324) and symbiotic stars (e.g. Cat.
J/A+A/143/343). Additional Henden sequences have been adopted from the
files cited below at the AAVSO ftp site. These large sequences were
trimmed to include only a few stars per magnitude interval, and also
to omit crowded stars (no significant companions closer than 15"
radius).
The star coordinates are mainly from early versions of the GSC or USNO
series. As such they are given to 1" precision, and in some cases
small systematic errors and (now) proper motion mean their accuracy is
in the 1" to 5" range. Thus for automated linkage to CCD frames, some
modest search radius should be adopted to match with the catalogue.
Because the file was originally intended for private use,
bibliographic references were not included except in a very few
instances. Usually it is straightforward to recover the source paper
by inspection of the SIMBAD bibliography for specific objects.
Problematic cases can be directed to the compiler (Brian Skiff).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
loneos.dat 132 34071 Photometric data
refs.txt 79 4079 Reference list (not complete)
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See also:
I/277 : SPM Catalog 2.0 (Platais+ 1998)
II/118 : UBVRI standards around Celestial Equator (Landolt 1983)
II/143 : Guide Star Photometric Catalog, Updated Ver.1 (Lasker+ 1988,1996)
II/168 : Homogeneous Means in the UBV System (Mermilliod 1991)
II/183 : UBVRI Photometric Standards (Landolt 1992)
II/215 : uvby-beta Catalogue (Hauck+ 1997)
VI/19 : UBV Photoelectric Sequences in SA 92-115 (Landolt 1973)
J/other/SAAOC/14.11 : UBVRI photometry of GSPC stars (Kilkenny+ 1990)
ftp://ftp.aavso.org/public/calib/ : Arne Henden photometry files
ftp://ftp.lowell.edu/pub/bas/starcats/cousins.stds : Cousins E- and F-region
primary standards
Byte-by-byte Description of file: loneos.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- Name Star name or field identification
20- 21 I2 h RAh Right Ascension (J2000) hour
23- 24 I2 min RAm Right Ascension (J2000) minute
26- 30 F5.2 s RAs Right Ascension (J2000) second
32 A1 --- DE- Declination sign
33- 34 I2 deg DEd Declination (J2000) degree
36- 37 I2 arcmin DEm Declination (J2000) minute
39- 42 F4.1 arcsec DEs Declination (J2000) second
44 A1 --- rPos ? Source of coordinates or mnemonic (1)
46- 54 A9 --- GSC GSC (Cat. I/255) number
56 A1 --- n_Vmag [*] if star is a standard star
57- 62 F6.3 mag Vmag V magnitude (precision varies)
64- 69 F6.3 mag B-V ? B-V color index (precision varies)
70 A1 --- u_B-V Uncertainty flag (:) on B-V
71- 76 F6.3 mag U-B ? U-B color index (precision varies)
77 A1 --- u_U-B Uncertainty flag (:) on U-B
78- 83 F6.3 mag V-R ? V-R color index (precision varies)
85- 90 F6.3 mag V-I ? V-I color index (precision varies)
93-111 A19 --- Bibcode ? Publication Source
114-132 A19 --- Remarks ? Comments
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Note (1): sources of astrometry (and some mnemonics for data sources)
are defined as follows:
A = USNO-A2.0 (1998USNO2.C......0M 1998USNO2.C......0M, Cat. I/252)
b = S. J. Bus unpublished photometry of Chiron fields
C = Cambridge APM-North (Cat. I/267)
D = DENIS (1999A&A...349..236E 1999A&A...349..236E, Cat. b/denis)
G = GSC-ACT (1999yCat.1255.....G 1999yCat.1255.....G, Cat. I/255)
g = GSC-2.2 (2001yCat.1271.....S 2001yCat.1271.....S, Cat. I/271)
h = Arne Henden photometry files
m = Massey et al (1995ApJ...454..151M 1995ApJ...454..151M, Cat. J/ApJ/454/151)
M = 2MASS second or all-sky releases (2006AJ....131.1163S 2006AJ....131.1163S,
Cat. II/241 or II/246)
S = SkyView estimate (±2")
T = all Hipparcos/Tycho-based catalogues, including in approximate
order of preference:
+ Tycho-2 (2000A&A...357..367H 2000A&A...357..367H, Cat. I/259)
+ TDSC (2002A&A...384..180F 2002A&A...384..180F, Cat. I/276)
+ TRC (1998A&A...335L..65H 1998A&A...335L..65H and 1999A&AS..136..491K 1999A&AS..136..491K, Cat. I/250)
+ ACT (1998AJ....115.2161U 1998AJ....115.2161U, Cat. I/246)
+ Hipparcos (1997HIP...C......0E 1997HIP...C......0E, Cat. I/239/hip_main)
+ Tycho-1 (1997HIP...C......0E 1997HIP...C......0E, Cat. I/239/tyc_main)
U = UCAC1 or UCAC2 (2000AJ....120.2131Z 2000AJ....120.2131Z, Cat. I/268 or I/289)
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History:
Prepared by Brian Skiff (Lowell Observatory, bas(at)lowell.edu)
(End) Brian Skiff [Lowell Obs.] 29-Mar-2007