J/PASP/114/1382 BVRI photometry of Stock 1 stars (Osborn+, 2002)
The neglected open cluster Stock 1.
Osborn W., Sano Y., Spalding R.
<Publ. Astron. Soc. Pac. 114, 1382 (2002) + Erratum 115, 761 (2003)>
=2002PASP..114.1382O 2002PASP..114.1382O
ADC_Keywords: Clusters, open ; Photometry, UBVRI ; Photometry, CCD
Abstract:
BVRI photometry and J2000.0 positions have been obtained for stars in
the field of the open cluster Stock 1. The photometry has been
combined with available spectral types and proper motions to
investigate cluster membership. We conclude that Stock 1 is a young
cluster with a reddening of E(B-V)=0.16±0.04, a distance modulus of
V0-MV=7.5±0.1, and an age of 300±50Myr.
Description:
The lack of attention to Stock 1 can be partially attributed to
difficulties with Stock's (1956ApJ...123..258S 1956ApJ...123..258S) finding chart. The
cluster lies in a crowded field, and the chart shows only the 158
stars Stock measured, omitting the other stars. It also contains some
errors. This has caused problems in identifying stars, particularly
the fainter ones. To resolve the ambiguities, we measured the stars'
x-y coordinates on a print of Stock's finding chart and then computed
equatorial coordinates, using the certain identifications for the
reference stars. Comparison of the resulting positions with the United
States Naval Observatory (USNO) A2.0 catalog (I/252) along with an
examination of the region on the Digitized Sky Survey1 allowed us to
identify all but stars 13. Our adopted J2000.0 coordinates for the
Stock 1 stars, as well as for a few other stars we observed, are given
in Table 1.
CCD observations of Stock 1 were obtained with standard BVRI filters
on 13 nights in the period 1999 October2000 September. The images were
obtained with a 576x384 Star-1 CCD camera on the Brooks Observatory
0.4m f/12 reflector. This system gives a field of view of 11'x8',
which generally allowed several Stock stars to be imaged on the same
frame. In a few cases, incoming clouds prevented observations of a
field with all filters.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 69 161 Positions and photometry
table2.dat 17 17 Spalding (1979, M.S. thesis, Central Michigan Univ)
photoelectric photometry
table3.dat 27 40 Cluster membership
--------------------------------------------------------------------------------
See also:
I/252 : The USNO-A2.0 Catalogue (Monet+ 1998)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Seq Sequential number, Cl* Stock 1 S NNNA in Simbad
6- 7 I2 h RAh Right ascension (J2000.0)
9- 10 I2 min RAm Right ascension (J2000.0)
12- 15 F4.1 s RAs Right ascension (J2000.0)
17 A1 --- DE- Declination sign (J2000.0)
18- 19 I2 deg DEd Declination (J2000.0)
21- 22 I2 arcmin DEm Declination (J2000.0)
24- 25 I2 arcsec DEs Declination (J2000.0)
27- 31 F5.2 mag Vmag ? V magnitude
33- 36 F4.2 mag B-V ? B-V colour index
38- 41 F4.2 mag V-R ? V-R colour index
43- 46 F4.2 mag V-I ? V-I colour index
48 I1 --- o_Vmag ? Number of nights of observation
49 A1 --- n_Vmag [T] T: transformed photographic data,
only V and B-V are given
51- 54 F4.2 mag e_Vmag ? rms uncertainty on Vmag
56- 59 F4.2 mag e_B-V ? rms uncertainty on B-V
61- 64 F4.2 mag e_V-R ? rms uncertainty on V-R
66- 69 F4.2 mag e_V-I ? rms uncertainty on V-I
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Seq Sequential number
6- 10 F5.2 mag Vmag V magnitude (average error of ±0.03)
12- 15 F4.2 mag B-V B-V colour index (average error of ±0.04)
17 I1 --- o_Vmag Number of nights of observations
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Seq Sequential number
6- 8 A3 --- MCMD Membership class from each of the five criteria
of color magnitude diagram position (1)
10- 12 A3 --- ME(B-V) Membership class from reddening(1)
14- 16 A3 --- MV0-MV Membership class from distance modulus (1)
18- 20 A3 --- Mpm Membership class from proper motion (1)
22- 23 A2 --- Mplx Membership from parallax (1)
25- 27 A3 --- Memb Adopted membership classification (1)
--------------------------------------------------------------------------------
Note (1): Membership codes as follows:
M = Member (M?: possible member)
NM = non-member (NM?: possible non-member)
F = Foreground (F?: Possible foreground)
B = Background (B?: Possible background)
--------------------------------------------------------------------------------
History:
* 06-Feb-2003: From electronic version of the journal
* 13-Apr-2007: table1 corrected, from erratum
(End) James Marcout, Patricia Bauer [CDS] 06-Feb-2003