J/MNRAS/430/3350 Proper motions and membership in NGC 3766 (Yadav+, 2013)
Proper motions and membership probabilities of stars in the region of open
cluster NGC 3766.
Yadav R.K.S., Sariya D.P., Sagar R.
<Mon. Not. R. Astron. Soc., 430, 3350-3358 (2013)>
=2013MNRAS.430.3350Y 2013MNRAS.430.3350Y
ADC_Keywords: Clusters, open ; Proper motions ; Photometry
Keywords: catalogues; astrometry -
Hertzsprung-Russell and colour-magnitude diagrams -
stars: kinematics and dynamics -
stars: luminosity function, mass function -
open clusters and associations: individual: NGC 3766
Abstract:
Relative proper motions (PMs) and cluster membership probabilities
(Pmu) were derived for ∼2500 stars in the field of the open star
cluster NGC 3766. The cluster was observed in the B and V broad-band
filters at two epochs separated by ∼6yr using a wide-field imager
mounted on the WFI@ESO 2.2-m telescope. All CCD frames were reduced
using the astrometric techniques described by Anderson et al.
(2006A&A...454.1029A 2006A&A...454.1029A, Paper I). The PM rms error for stars brighter
than V∼15mag is 2.0mas/yr, but it gradually increases up to ∼4mas/yr
at V∼20mag. Using PM data, membership probabilities were derived for
the stars in the region of the cluster. They indicate that one Ap and
three Be stars are members of the cluster. A reddening of
E(B-V)=0.22±0.05mag, a distance of 2.5±0.5kpc and an age of ∼20Myr
were derived using stars with Pmu>70 per cent. A mass function slope
of x=1.60±0.10 was derived for the cluster, and the cluster was
found to be dynamically relaxed. Finally, we provide positions,
calibrated B and V magnitudes, relative PMs and membership
probabilities for the stars in the field of NGC 3766. We have produced
a catalogue that is electronically available to the astronomical
community.
Description:
CCD data for NGC 3766 were collected with the wide-field imager camera
(WFI) mounted on the 2.2-m ESO/MPI telescope at La Silla, Chile. Using
the archival data of two epochs, PMs were computed. The first epoch
consists of four images in the B filter and three images in the V
filter taken on 2000 February 27, while the second epoch has four
images in the V filter taken on 2006 April 9.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 104 2468 Catalogue of proper motions with their corresponding
uncertainties and membership probabilities for about
2500 stars in the region of NGC 3766
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See also:
J/ApJ/622/1052 : byHα photometry of NGC 3766 (McSwain+, 2005)
J/A+A/554/A108 : Periodic variables in NGC 3766 (Mowlavi+, 2013)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [1/2468] Sequential number
6- 7 I2 h RAh Right ascension (J2000)
9- 10 I2 min RAm Right ascension (J2000)
12- 16 F5.2 s RAs Right ascension (J2000)
18 A1 --- DE- Declination sign (J2000)
19- 20 I2 deg DEd Declination (J2000)
22- 23 I2 arcmin DEm Declination (J2000)
25- 28 F4.1 arcsec DEs Declination (J2000)
30- 37 F8.3 pix Xpos X position
39- 46 F8.3 pix Ypos Y position
48- 54 F7.3 mas/yr pmRA Proper motion along RA, pmRA*cosDE
56- 60 F5.3 mas/yr e_pmRA rms uncertainty on pmRA
62- 68 F7.3 mas/yr pmDE Proper motion along DE
70- 74 F5.3 mas/yr e_pmDE rms uncertainty on pmDE
76- 81 F6.3 mag Bmag B magnitude
83- 87 F5.3 mag e_Bmag rms uncertainty on Bmag
89- 94 F6.3 mag Vmag V magnitude
96-100 F5.3 mag e_Vmag rms uncertainty on Vmag
102-104 I3 % Pmu [0/100] Membership probability
from proper motion
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 16-Apr-2014