J/A+A/544/A111 Low-mass stars in Coma Ber (Melnikov+, 2012)
The mass function of the Coma Berenices open cluster below 0.2 M☉:
a search for low-mass stellar and substellar members.
Melnikov S., Eisloeffel J.
<Astron. Astrophys., 544, A111 (2012)>
=2012A&A...544A.111M 2012A&A...544A.111M
ADC_Keywords: Clusters, open ; Infrared sources ; Photometry
Keywords: brown dwarfs - stars: low-mass -
open clusters and associations: individual: Coma Berenices -
stars: late-type
Abstract:
Little is known about the population of the Coma Berenices open
cluster (age∼500Myr) below 0.2M☉, and statistics show that there
is a prominent deficit of very low-mass objects in this mass range
compared to younger open clusters with ages of <250Myr.
We search for very low-mass stars and substellar objects (brown
dwarfs) in the Coma open cluster to derive the present-day cluster
mass function below 0.2M☉.
Description:
An imaging survey of the Coma open cluster in the R- and I-bands was
carried out with the 2kx2k CCD Schmidt camera at the 2-m telescope
in Tautenburg. The photometric survey was carried out during two runs
in April - June 2006 and January 2007. We performed a photometric
selection of the cluster member candidates by combining results of our
survey with 2MASS JHKs photometry. We also analysed low-resolution
optical spectroscopic observations of a sample of 14 of our stellar
cluster member candidates to estimate their spectral types and
luminosity.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 94 82 RI and 2MASS JHKs photometry of Coma open cluster
member candidates
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See also:
J/AJ/134/2340 : Membership of Praesepe and Coma Ber clusters (Kraus+, 2007)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
http://www.ukidss.org : UKIDSS Home Page
Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Object Object name (FF-NNNN)
8 A1 --- n_Object [ab] Note on source (1)
10- 25 A16 --- OName 2MASS or UKIDSS name
27- 28 I2 h RAh Right ascension (J2000)
30- 31 I2 min RAm Right ascension (J2000)
33- 36 F4.1 s RAs Right ascension (J2000)
38 A1 --- DE- Declination sign (J2000)
39- 40 I2 deg DEd Declination (J2000)
42- 43 I2 arcmin DEm Declination (J2000)
45- 46 I2 arcsec DEs Declination (J2000)
48- 52 F5.2 mag Imag I magnitude
54- 57 F4.2 mag e_Imag rms uncertainty on Imag
59- 62 F4.2 mag R-I R-I colour index
64- 67 F4.2 mag e_R-I rms uncertainty on R-I
69- 73 F5.2 mag Jmag 2MASS J magnitude
75- 79 F5.2 mag Hmag 2MASS H magnitude
81- 85 F5.2 mag Ksmag 2MASS Ks magnitude
87- 88 A2 --- SpT1 Spectral type from I magnitude
90- 94 A5 --- SpT2 Spectral type from JHKs magnitudes
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Note (1): Notes as follows:
a = Object is identified with a cluster member candidate from Kraus &
Hillenbrand (2007, Cat. J/AJ/134/2340)
b = ID of the object and its JHK photometry is given according to the
UKIDSS database.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 18-Oct-2012