CDROM/AJ/V106/P0181
M67 (Montgomery+ 1993)
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CCD Photometry of the Old Open Cluster M67
Kent A. Montgomery, Laurence A. Marschall, & Kenneth A. Janes
<1993, AJ, 106, 181>
=1993AJ....106..181M
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Abstract:
We present a CCD photometric survey of the central one-half degree of
the old open cluster, M67, in U, B, V, and I colors to magnitude V=20.
Extensive comparison of our photometry with other published datasets
shows excellent agreement, indicating that CCD photometry is capable of
producing a uniform set of measurements consistent with the photometric
system defined primarily by the Landolt standard sequence. The
color-magnitude diagram of the cluster shows a well-defined main
sequence extending at least to the limit of the photometry at
M(V)=10.55 and a substantial binary sequence. At least 38% of cluster
stars are binaries. The current generation of theoretical isochrones
cannot be fit to the observed sequences within the observational
errors. We find a tendency for more massive members of the cluster to
be more centrally concentrated, along with a turnover in the cluster
luminosity function at low masses, which may be due to dynamical
relaxation of the cluster. To the limit of our photometry, we find a
mass of the cluster of 724 solar masses. In addition, we present a
sample of stars of well-determined standard magnitudes that are
suitable as photometric standards for further studies of this cluster
and for general calibration of the UBVI photometry using CCDs.
File Summary:
------------------------------------------------------------------------------File Name
Lrecl
Records
Explanations
------------------------------------------------------------------------------table3.dat
136
1456
Photometry
------------------------------------------------------------------------------Comments for file: table3.dat
------------------------------------------------------------------------------Table 3 contains all Montgomery et al. (1993) stars as well as stars
brighter than 12th magnitude from previously published data. MMJ star
numbers followed by an asterisk correspond to stars which fall on the
photometric binary sequence in the color-magnitude diagram. MMJ star
numbers enclosed in parentheses indicate stars with a V magnitude
brighter than 12; their photometry is compiled from previously
published sources. The last eighteen characters correspond to cross
referencing. The first number corresponds to Sanders (1977, A&AS, 27,
89), numbers preceded with a roman numeral are from Eggen & Sandage
(1964, ApJ, 140, 130), numbers preceded with an F are from Fagerholm
(1906, Inaugural dissertation, Uppsala), numbers preceded with a G
refer to Gilliland et al. (1991, AJ, 101, 541). The sources of
photometry of stars brighter than 12th magnitude are enclosed in
parentheses in the comments (to match the MMJ star number) as given in
Table 4 of the printed paper: (ES) for Eggen & Sandage (1964), (JS)
for Janes & Smith (1984, AJ, 89, 487), (G) for Gilliland et
al. (1991), (M) for Murray et al. (1965, Roy. Obs. Bull., No. 91),
and (S) for Sanders (1989, RMxA, 17, 31).
------------------------------------------------------------------------------Byte-by-byte Description of file: table3.dat
------------------------------------------------------------------------------Bytes Format Units
Label
Explanations
------------------------------------------------------------------------------1
1X
--Lpar
[(] Left parenthesis, see comments
2- 5 I4
--MMJ
MMJ star number
6
A1
--Rpar
[)*] Asterisk or right paren, see
comments
7
1X
----Blank
8- 10 F3.0
h
RAh
Right ascension (1950)
11- 13 F3.0
min
RAm
R.A.
14- 19 F6.2
s
RAs
R.A.
20
1X
----Blank
21
A1
--DESign of declination (always blank)
22- 23 F2.0
deg
DEd
Declination (1950)
24- 26 F3.0
arcmin
DEm
Dec.
27- 31 F5.1
arcsec
DEs
Dec.
32- 38 F7.3
mag
V
V magnitude
39- 45 F7.3
mag
B-V
B-V color
46- 52 F7.3
mag
U-B
[]? U-B color
53- 59 F7.3
mag
V-R
[]? V-R color
60- 66 F7.3
mag
V-I
[]? V-I color
67- 72 F6.3
mag
e_V
V error
73- 78 F6.3
mag
e_B-V
B-V error
79- 84 F6.3
mag
e_U-B
U-B error
85- 90 F6.3
mag
e_V-R
V-R error
91- 96 F6.3
mag
e_V-I
V-I error
97-101 F5.2
arcsec
e_RADE
positional error
102-104 I3
--n_V
Number of V obs
105-107 I3
--n_B
Number of B obs
108-110 I3
--n_U
Number of U obs
111-113 I3
--n_R
Number of R obs
114-116 I3
--n_I
Number of I obs
117-118 2X
----Blank
119-136 A18
--Comment Comments (see description above)
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(End)
Lee Brotzman [ADS] 08Mar-1995