J/A+A/470/585 NGC 2682 uvby-Hbeta photometry (Balaguer-Nunez+, 2007)
uvby-Hβ CCD photometry and membership segregation of the open cluster
NGC 2682 (M 67).
Balaguer-Nunez L., Galadi-Enriquez D., Jordi C.,
<Astron. Astrophys. 470, 585 (2007)>
=2007A&A...470..585B 2007A&A...470..585B
ADC_Keywords: Clusters, open ; Photometry, CCD ; Photometry, uvby, beta
Keywords: Galaxy: open clusters and associations: individual: NGC 2682 -
techniques: photometry - astrometry -
methods: observational - methods: data analysis
Abstract:
Following deep astrometric and photometric study of the cluster
NGC 2682 (M 67), we are able to accurately determine its fundamental
parameters. Being an old and rich cluster, M 67 is relevant for the
analysis of the Galactic disk evolution. M 67 is well studied but
lacks a wide and deep Stroemgren photometric study. The brightest
stars of the open cluster M 67 were used as uvby-Hbeta standard stars
in our studies of NGC 1817 and NGC 2548, and the extension of the
field covered, as well as the number of observations, allowed us to
obtain the best set of Stroemgren data ever published for this
cluster. We discuss the results of our CCD uvby-Hbeta
intermediate-band photometry, covering an area of about 50'x50' down
to V∼19. Moreover, a complete membership segregation based on
astrometric and photometric criteria is obtained. The photometric
analysis of a selected sample of stars yields a reddening value of
E(b-y)=0.03±0.03, a distance modulus of V0-MV=9.7±0.2 and
[Fe/H]=0.01±0.14. Through isochrone fitting we found an age of
logt=9.6±0.1 (4.2±0.2Gyr). A clump of approximately 60 stars
around V=16, (b-y)=0.4 could be interpreted as a population of
pre-cataclysmic variable stars (if members), or as a stream of field
G-type stars placed at twice the distance of the cluster (if
non-members).
Description:
The catalogue of uvby-Hbeta and J2000 coordinates for 1843 stars
in an area of 50'x50' around NGC 2682. We mark the selection of
probable members of NGC 2682, combining the photometric study with
an astrometric analysis.
The cross-identification of stars in common with the astrometry
(Zhao et al., 1993, Cat. J/A+AS/100/243), BDA
(htpp://obswww.unige.ch/WEBDA), Sanders (1977A&AS...27...89S 1977A&AS...27...89S),
Hipparcos (ESA, 1997, Cat. I/239), Tycho-2 (Hog et al., 2000,
Cat. I/259), and USNO-2 (Monet et al., 1998, Cat. I/252)
catalogues. The proper motions from Zhao et al. (1993, Cat.
J/A+AS/100/243), their errors and membership probabilities of
1046 stars in the area of M∼67, with parametric and non parametric
membership probabilities.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 136 1843 Stromgren photometry of stars in NGC 2682 area
table4.dat 82 1843 Cross-identification of stars
table7.dat 62 1046 Parametric and Non-Parametric Astrometric Probability
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See also:
I/252 : The USNO-A2.0 Catalogue (Monet+ 1998)
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
J/A+AS/100/243 : Proper motions in M 67 (Zhao+, 1993)
http://www.univie.ac.at/webda : WEBDA Database
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Seq Sequential identification number
7- 8 I2 h RAh Right ascension (J2000)
10- 11 I2 min RAm Right ascension (J2000)
13- 18 F6.3 s RAs Right ascension (J2000)
20- 21 I2 deg DEd Declination (J2000)
23- 24 I2 arcmin DEm Declination (J2000)
26- 30 F5.2 arcsec DEs Declination (J2000)
31- 39 F9.3 arcmin xpos x-frame coordinate in arcmin
40- 48 F9.3 arcmin ypos y-frame coordinate in arcmin
49- 57 F9.3 mag b-y ?=99.99 b-y color index
58- 65 F8.4 mag e_b-y ?=9.99 error in b-y
66- 74 F9.3 mag Vmag ?=99.99 V magnitude
75- 82 F8.4 mag e_Vmag ?=9.99 error in Vmag
83- 91 F9.3 mag m1 ?=99.99 Stroemgren m1 color index
92- 99 F8.4 mag e_m1 ?=9.99 error in m1
100-108 F9.3 mag c1 ?=99.99 Stroemgren c1 color index
109-116 F8.4 mag e_c1 ?=9.99 error in c1
117-125 F9.3 mag Hb ?=99.99 Stroemgren Hbeta color index
126-133 F8.4 mag e_Hb ?=9.99 error in Hbeta
135-136 A2 --- Mem [M NM] Membership label
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Seq Sequential identification number
7- 8 I2 h RAh Right ascension (J2000)
10- 11 I2 min RAm Right ascension (J2000)
13- 18 F6.3 s RAs Right ascension (J2000)
20- 21 I2 deg DEd Declination (J2000)
23- 24 I2 arcmin DEm Declination (J2000)
26- 30 F5.2 arcsec DEs Declination (J2000)
32- 36 I5 --- Zhao ?=0 Zhao et al. 1993, Cat. J/A+AS/100/243,
number, CL* NGC 2682 ZTP NNNN in Simbad
38- 42 I5 --- BDA ?=0 BDA identification number
44- 49 A6 --- San Sanders (1977A&AS...27...89S 1977A&AS...27...89S) identification
number
50- 55 I6 --- HIP ?=0 Hipparcos (I/239) identification number
57- 61 I5 --- TYC1 ?=0 TYC1 (I/239) identification number
63- 67 I5 --- TYC2 ?=0 TYC2 (I/259) identification number
68- 82 A15 --- USNO2 USNO2 (I/252) identification number
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Zhao Zhao et al (1993, Cat. J/A+AS/100/243)
number, CL* NGC 2682 ZTP NNNN in Simbad
6- 11 A6 --- San Sanders (1977A&AS...27...89S 1977A&AS...27...89S) identification
number, Cl* NGC 2682 Sand NNNNa in Simbad
13- 17 F5.2 mag Bmag Photographic B magnitude (1)
19- 23 F5.2 mag Vmag ? Photographic V magnitude (1)
25- 30 F6.1 mas/yr pmX Proper motion in x
32- 35 F4.1 mas/yr e_pmX error in PMx
37- 42 F6.1 mas/yr pmY Proper motion in y
44- 47 F4.1 mas/yr e_pmY error in PMy
49- 53 F5.2 --- MembP Parametric membership probability
55- 59 F5.2 --- MembNP Non-parametric membership probability
61- 62 I2 --- Nplates Number of plates
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Note (1): Magnitudes from Sanders (1977A&AS...27...89S 1977A&AS...27...89S)
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Acknowledgements:
Lola Balaguer-Nunez, lola.balaguer(at)am.ub.es
(End) L. Balaguer-Nunez [Univ. de Barcelona], P. Vannier [CDS] 10-May-2007