J/AJ/106/1533 NGC 2287 (Harris+, 1993)
NGC 2287: an important intermediate-age open cluster
HARRIS G.L.H., FITZGERALD P.M., MEHTA S., REED B.C.
<Astron. J. 106, 1533 (1993)>
=1993AJ....106.1533H 1993AJ....106.1533H (SIMBAD/NED Reference)
Abstract:
We have obtained photoelectric UBV photometry for 100 stars, uvbyBeta
photometry for 39 stars and MK spectral types for 80 stars in the field
of NGC 2287. After combination with data from other sources, several
interesting cluster properties are apparent. Both the UBV and uvbyBeta
photometry point to a small but nonzero reddening, while our spectral
types confirm previous results indicating a high binary frequency for
the cluster. Based on our spectral and photometric data for the
cluster members with -1≲M(V)≲3 we find a minimum binary
frequency of 40% and discuss the possibility that the results may imply
a binary frequency closer to 80%. The cluster age is found to be
∼2x10^8yr based on both the main-sequence turnoff and the red giant
distribution; the width of the turnup region can probably be explained
by a combination of duplicity and a range in stellar rotation.
File Summary:
--------------------------------------------------------------------------------
File Name Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
macros.tex 80 366 macros for the tables in TeX
table1 152 239 UBV photometry in NGC 2287
table1a.tex 115 1444 TeX version of table1 (left part)
table1b.tex 86 1445 TeX version of table1 (right part)
table2 102 59 uvbyBeta photometry in NGC 2287
table2.tex 145 267 TeX version of table2
table4 89 138 MK spectral types in NGC 2287
table4.tex 71 545 TeX version of table4
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- HFMR Identification number
8 A1 --- MembA Adopted cluster membership, based on overall
indicators (1)
10 A1 --- MembE Excess membership indicator based on
consistency relation to the main sequence (1)
11 A1 --- MembS Spectrum membership indicator based on
agreement of photometric and spectroscopic
type (1)
12 A1 --- MembL Luminosity membership indicator based on
agreement of photometric and spectroscopic
class (1)
13 A1 --- MembZ ZAMS+CMD membership indicator based on
position in color-magnitude diagram,
especially for near-ZAMS (Zero-Age
Main-Sequence) stars (1)
16- 25 A10 --- Name Identification numbers from other authors,
Cox (1954), Hoag et al. (1961), or
Ianna et al. (1987)
26- 31 F6.3 mag Vmag Mean V magnitude
33 A1 --- Var [V ] Variability flag, 'V', or blank
34- 36 I3 10-3mag e_Vmag rms uncertainty on V magnitude. (2)
38- 43 F6.3 mag B-V []? Mean (B-V) color
45- 47 I3 10-3mag e_B-V []? rms uncertainty on mean (B-V) color
49- 54 F6.3 mag U-B []? Mean (U-B) color
56- 58 I3 10-3mag e_U-B []? rms uncertainty on mean (U-B) color
61- 64 F4.2 --- Sp []? Spectral type derived from photometric
data
65 A1 --- u_Sp Uncertainty flag on spectral type
67- 69 F3.1 --- LC []? Luminosity class derived from photometric
data
70 A1 --- u_LC Uncertainty flag on luminosity class
72- 73 I2 --- Nobs1 []? Number of observations in this paper
75- 76 I2 --- Nobs2 []? Number of observations in
Feinstein et al., (1978)
78- 79 I2 --- Nobs3 []? Number of observations in Cox (1954)
81 I1 --- Nobs4 []? Number of observations in Eggen (1974)
83 I1 --- Nobs5 []? Number of observations in
Hoag et al. (1961) (photoelectric)
85 I1 --- Nobs6 []? Number of observations in
Hoag et al. (1961) (photographic)
87 I1 --- Nobs7 []? Number of observations in
Ianna et al. (1987)
90-104 A15 --- MKSp Adopted MK class, primarily from this paper.
Classes in parentheses, "()", are from other
sources.
106-111 F6.3 mag V0 []? Intrinsic V(0) magnitude derived by
WATREDAO
112 A1 --- u_V0 Uncertainty flag on intrinsic V(0) magnitude
113 A1 --- Var [V ] A 'V' indicates variability
114-117 I4 10-3mag e_V0 []? rms uncertainty on V(0).
118 A1 --- ueV0 rms uncertainty on e_V(0).
120-125 F6.3 mag (B-V)0 []? Intrinsic (B-V)(0) color derived by
WATREDAO
126 A1 --- u_(B-V)0 Uncertainty flag on (B-V)0
128-130 I3 10-3mag e_(B-V)0 []? rms uncertainty on (B-V)(0).
131 A1 --- ueB-V Uncertainty flag on e_(B-V)0
133-138 F6.3 mag DistMod []? (V(0)-Mv) derived assuming the star
lies on the Zero-Age Main-Sequence
140-143 I4 10-3mag e_DistMod []? rms uncertainty on distance modulus
145-152 A8 --- Notes Notes (3)
--------------------------------------------------------------------------------
Note (1): Codes for cluster membership indicators
B Probable binary member of cluster.
b Possible binary member of cluster.
C Possibly C+E.
E Probably evolved.
G Probable member of background group.
g Possible member of background group.
F Probable field object.
f Possible field object.
N Non-member of cluster or background group.
n Possible non-member of cluster or background group.
M Probable cluster member.
m Possible cluster member.
u No U-B but photometry consistent with membership at mean cluster extinction
X Non-member due to incorrect color excess.
Z Probable member on the ZAMS.
z Possibly member on the ZAMS.
Note (2): Errors reported in this table are based on observational error and
estimates from other authors. For derived quantities the errors are
those propagated through the photometric dereddening process.
Note (3):
A Near A hump in two color diagram; color excess could be too large.
H Near F hump in two color diagram; color excess could be too large or small.
1 Smallest color excess chosen.
2 Second smallest color excess chosen.
3 Possibly contaminated by a nearby object.
4 Duplicity indicated by some MK classifications.
5 MK adopted is not from this study and is shown in brackets.
6 Binary; 0.5 to 0.8 magnitudes and more than 2 sigma above ZAMS.
7 Colors and spectrum incompatible.
8 Photometric spectrum and colors may be uncertain for bright giants.
9 Color excess chosen to suit membership and/or mean color excess.
10 Color excess more than 1 sigma from the mean.
12 Bad U-B?
13 Deconvolved binary star.
15 Luminosity class incompatible with membership.
16 Color excess too high for membership,but star not necessarily excluded.
17 Outside cluster radius suggested by star counts.
18 Luminosity class supports duplicity.
19 6, 11, and 12.
20 7, 10, and 14.
21 Quoted photometry is from Ianna, Adler and Faudree.
22 U-B from Ianna et al.
23 10, 16, 17, and 21.
24 10, 17, and 21.
: A colon indicates that the data are of poorer than average quality,
so that conclusions in the footnotes which the colon follows are
uncertain, suspect...
For HFMR 1ABR, 3" is the angular separation for the A and B components.
For HFMR 92, 5" is the angular separation for the A and B components.
References:
Cox, A. N. 1954, ApJ, 119, 188
Eggen, O. J. 1974, ApJ, 188, 59
Feinstein, A., Cabrera, A. L. & Claria, J. J. 1978, A&AS, 43, 241
Hoag, A. A., Johnson, H. L., Iriarte, B., Mitchell, R. I., & Hallam, K. L., &
Sharpless, S. 1961, Pub. U.S. Naval Obs., 17, 349
Ianna, P. A., Adler, D. S., & Faudree, E. F. 1987, AJ, 93, 347
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- HFMR Identification number
8- 13 F6.3 mag V Mean V magnitude
15- 16 I2 10-3mag e_V rms uncertainty on mean V magnitude
18- 23 F6.3 mag b-y Mean (b-y) color
25- 26 I2 10-3mag e_b-y rms uncertainty on mean (b-y) color
28- 33 F6.3 mag m1 Mean m(1) index
35- 36 I2 10-3mag e_m1 rms uncertainty on mean m(1) index
38- 43 F6.3 mag c1 Mean c(1) index
45- 46 I2 10-3mag e_c1 rms uncertainty on mean c(1) index
48- 52 F5.3 mag Beta []? Mean Beta
54- 55 I2 10-3mag e_Beta []? rms uncertainty on mean Beta
57- 58 I2 --- HF []? Number of photometric observations from
this paper
59- 60 I2 --- E1 []? Number of photometric observations taken
from Eggen (1974)
61- 62 I2 --- E2 []? Number of photometric observations taken
from Eggen (1981)
65- 66 A2 --- Code [ABF0 ] Code for method used to derive
individual values of E(b-y) and V(0)-Mv:
A Crawford (1979)
A0 Claria (1974) adapted from Stromgren
(1966) as described by Eggen (1981)
B Crawford (1978)
F Crawford (1975)
67- 73 F7.3 --- E(b-y) []? Reddening E(b-y)
74- 81 F8.3 mag V0 []? Intrinsic V(0) magnitude
82- 89 F8.3 mag MV []? Absolute V magnitude
90- 95 F6.2 mag DistMod []? Distance modulus V(0)-Mv
98- 99 A2 --- Membu Membership indicator from uvbyBeta photometry
V(0)-Mv (1)
101-102 A2 --- MembU Membership indicator from UBV analysis of
table1 (1)
--------------------------------------------------------------------------------
Note (1):
b Possible binary member of cluster
F Probable field object
f Possible field object
G Probable member of background group
M Probable cluster member
m Possible cluster member
n Possible non-member of cluster or background group
References:
Claria, J. J. 1974, Elementos de Fotometria Estellar, Instituto Venezolano de
Astronomia (Merida, Venezuela)
Crawford, D. L. 1975, AJ, 80, 955
Crawford, D. L. 1978, AJ, 83, 48
Crawford, D. L. 1979, AJ, 84, 1858
Eggen, O. J. 1974, ApJ, 188, 59
Eggen, O. J. 1981, ApJ, 247, 507
Stromgren, B. 1966, ARA&A, 4, 433
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- HFMR Identification number
6- 20 A15 --- MKSp Adopted MK type (1)
22- 43 A22 --- MKSp1 MK type from a single plate
45- 52 A8 "DD/MM/YY" Date Date of observation
54- 56 A3 --- Rem Remarks (2)
59- 82 A24 --- MKSp2 Other MK type
84- 89 A6 --- Ref References. The notation "[2]" indicates that
the spectral type is for both stars
in the pair (3)
--------------------------------------------------------------------------------
Note (1): Spectral types
? uncertain or conflicting criteria;
: poor plate;
/ either range possible or between types given;
- between types given;
sV spectrum variable;
SB2 H lines stronger than standards, broad and strong cores, atypical
profiles (see LM).
Note (2): Key to remarks
A. Possible contamination from 1A.
B. Poor standards at luminosity class III.
C. Possible peculiar Hgamma.
D. Hbeta,gamma lines show sharp core, diffuse wings.
E. SB2?
F. H lines broad; not n?
G. H line wings slightly peculiar, luminosity difficult to determine.
H. Very poor spectrum, moon contamination? Am?
I. possible rotational broadening? sV?
J. H lines ∼ A0; weak G band, metal lines.
K. Ca very strong; H lines peculiar.
L. Could be III; very poor spectrum.
M. H profiles square -> SB2?
N. Poor luminosity standards; adopted LM type.
O. H lines diffuse but no sharp core.
P. Could be double not rotation.
Q. H lines sharp; He4026 present.
R. H lines broad; weak CaK, no He4026.
S. Spectra for this star definitely different from each other.
T. Hgamma,delta peculiar?
U. Luminosity difficult to determine.
V. Hgamma,delta double, CaK broad.
W. Both CaK and He4026 present.
X. Possible Ap or composite.
Y. Hbeta,epsilon suggest n?
Z. Possible composite?
a. Possible weak Si4128.
b. Standards poor; definitely more luminous than IIIb.
c. Possible He4026?
d. Possible square profiles.
e. Either composite or shell.
f. Spectra slightly different.
g. A star appears stronger in 1981 exposure.
h. Adopted LM type.
i. He weak?
j. CaK sharper than H lines?
k. Hint of TiII 3993?
Note (3): References
C Cox, A. N. 1954, ApJ, 119, 188
H Hartoog, M. R. 1976, AJ, 205, 807
LG Levato, H., & Garcia, B. 1984, ApJ, 24, L161
LM Levato, H., & Malaroda, S. 1979, PASP, 91, 636
RHH van Rensbergen, W., Hammerschlag-Hensberge, G.,
& van den Heuvel, E. P. J. 1978, A&A, 64, 131
S Sowell, J. R. 1987, ApJS, 64, 241
--------------------------------------------------------------------------------
Origin: AAS CD-ROM series, Volume 1, 1993
(End) Patricia Bauer [CDS] 16-Sep-1994