J/A+A/423/189 UBV and RV of red giants in NGC 2477 (Eigenbrod+, 2004)
Red giants in open clusters: XI. Membership, duplicity and structure of NGC 2477
Eigenbrod A., Mermilliod J.-C., Claria J.J., Andersen J., Mayor M.
<Astron. Astrophys. 423, 189 (2004)>
=2004A&A...423..189E 2004A&A...423..189E
ADC_Keywords: Clusters, open ; Stars, giant ; Radial velocities ;
Photometry, UBV
Keywords: stars: binaries: spectroscopic - techniques: radial velocities -
star: late-type -
Galaxy: open cluster and associations: individual: NGC 2477
Abstract:
New, accurate radial velocities and photoelectric UBV photometry of 83
red-giant candidates in the field of the rich, intermediate-age open
cluster NGC 2477 ([Fe/H]=-0.05, age ∼1Gyr) are presented and
discussed. From 49 constant-velocity members we find a mean cluster
velocity of +7.32±0.13km/s and confirm the membership of 76 of the
stars. Among the cluster members, we identify 26 definite and 1
probable spectroscopic binaries and determine orbits for 13 of these
systems, with periods ranging from 40 to 4578 days. The binary
frequency is thus rather high (27/76=36%). The observed internal
radial velocity dispersion of the cluster, as determined from the
single member stars, is 0.93km/s, corrected for the small average
observational error of 0.22km/s. Fitting King-type models to the
observed stellar density distribution and velocity dispersion, and
assuming a distance of 1.25kpc, we find the core and tidal radii of
NGC 2477 to be 1.8 and 8.1pc, respectively, and estimate that the
mass of cluster stars down to V=17, corresponding to ∼1M☉, is at
least 5400 M☉. The substantial differential reddening of NGC 247
requires a more detailed study before definitive isochrone fits can be
made.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 111 83 Mean photometric and radial-velocity data
table2.dat 42 704 Radial-velocity data
--------------------------------------------------------------------------------
See also:
J/A+A/299/53 : Red giants in NGC 3680 and IC 4651 (Mermilliod+, 1995)
J/A+A/307/80 : Velocities of red giants in NGC 2099 (Mermilliod+ 1996)
J/A+A/319/481 : 10 spectroscopic binaries radial velocities (Mermilliod+ 1997)
J/A+A/324/91 : Melotte 71 red giants radial velocities (Mermilliod+ 1997)
J/A+A/339/423 : Velocities of red giants in NGC 752 (Mermilliod+ 1998)
J/A+A/375/30 : Radial velocities in open clusters (Mermilliod+, 2001)
J/A+A/399/105 : Radial velocities of red giants in NGC 1817 (Mermilliod+ 2003)
J/A+AS/134/301 : NGC 2354 red giants (Claria+ 1999)
http://obswww.unige.ch/webda/navigation.html : WEBDA database
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- --- [NGC 2477] Cluster name
10- 13 I4 --- Star Star number (as in WEBDA)
15- 21 A7 --- Hart Original identification from Hartwick et al.,
1972ApJ...174..557H 1972ApJ...174..557H, Cl* NGC 2477 Hart NNNNNNN
23- 26 I4 --- ID2 ? Original identification Hartwick & Hesser,
1974ApJ...192..391H 1974ApJ...192..391H, Cl* NGC 2477 Hart NNNN
28 I1 h RAh Right ascension (J2000)
30- 31 I2 min RAm Right ascension (J2000)
33- 38 F6.3 s RAs Right ascension (J2000)
40 A1 --- DE- Declination sign (J2000)
41- 42 I2 deg DEd Declination (J2000)
44- 45 I2 arcmin DEm Declination (J2000)
47- 51 F5.2 arcsec DEs Declination (J2000)
53- 58 F6.3 mag Vmag V magnitude
60- 65 F6.3 mag B-V (B-V) colour index
67- 72 F6.3 mag U-B (U-B) colour index
74 I1 --- o_Vmag Number of UBV measurements
76- 81 F6.2 km/s RV Mean radial velocity
83- 86 F4.2 km/s e_RV Error on the radial velocity
88- 89 I2 --- o_RV Number of RV measurements
91- 94 I4 d Time Interval of time
96-100 F5.3 --- P(chi2) Probability of variability
102-106 F5.3 --- Prob Membership probability from RV
108-110 A3 --- Notes Remarks (NM, SB, SBO)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- --- [NGC 2477] Cluster name
10- 13 I4 --- Star Star number (as in WEBDA)
17- 27 F11.3 d HJD Heliocentric Julian Date
30- 35 F6.2 km/s HRV Heliocentric Radial velocity
39- 42 F4.2 km/s e_HRV Error on the radial velocity
--------------------------------------------------------------------------------
Acknowledgements: Jean-Claude Mermilliod
History:
* 24-Sep-2004: in table2, the star number 8217 was changed to 8216.
References:
Mermilliod et al. Paper I 1989A&A...219..125M 1989A&A...219..125M
Mermilliod et al. Paper II 1989A&AS...79...11M 1989A&AS...79...11M
Mermilliod & Mayor Paper III 1990A&A...237...61M 1990A&A...237...61M
Mermilliod et al. Paper IV 1995A&A...299...53M 1995A&A...299...53M, Cat. J/A+A/299/53
Mermilliod et al. Paper V 1996A&A...307...80M 1996A&A...307...80M, Cat. J/A+A/307/80
Mermilliod et al. Paper VI 1997A&A...319..481M 1997A&A...319..481M, Cat. J/A+A/319/481
Mermilliod et al. Paper VII 1997A&A...324...91M 1997A&A...324...91M, Cat. J/A+A/324/91
Mermilliod et al. Paper VIII 1998A&A...339..423M 1998A&A...339..423M, Cat. J/A+A/339/423
Mermilliod et al. Paper IX 2001A&A...375...30M 2001A&A...375...30M, Cat. J/A+A/375/30
Mermilliod et al. Paper X 2003A&A...399..105M 2003A&A...399..105M, Cat. J/A+A/399/105
(End) Patricia Vannier [CDS] 06-May-2004