J/A+A/419/249 RJHKs photometry of sigma Ori low-mass stars (Scholz+, 2004)
Rotation and accretion of very low mass objects in the sigma Ori cluster.
Scholz A., Eisloeffel J.
<Astron. Astrophys. 419, 249 (2004)>
=2004A&A...419..249S 2004A&A...419..249S
ADC_Keywords: Associations, stellar ; Photometry, infrared ; Stars, masses
Keywords: techniques: photometric - stars: low-mass, brown dwarfs -
stars: rotation - stars: formation - stars: activity -
stars: magnetic fields
Description:
Coordinates and photometry of probable cluster members in the sigma
Ori cluster. Time series observations of this cluster were carried out
using the CCD cameras at the 2m Schmidt telescope of the Thuringer
Landessternwarte Tautenburg (TLS) and the 1.23m telescope on Calar
Alto (CA). From these images, we derived coordinates (columns 2 and 3)
as well as photometry in the R- and I-band (columns 5 and 6).
Additional near- infrared photometry in J, H, K comes from the 2MASS
database (columns 7-9). The cluster member selection is based on
(I,I-J) colour magnitude diagrams. The R-I and J-H colours were used
to reject contaminating field stars. The column 4 indicates whether
the object was identified with the CA photometry (c), the TLS
photometry (t), or both. The masses given in column 10 were estimated
by comparing the near-infrared photometry with the evolutionary tracks
of Baraffe et al. (1998A&A...337..403B 1998A&A...337..403B). These tracks cover the mass
range from 0.02 to 1.4 solar masses, for some objects with lower or
higher masses we give upper or lower mass limits. The last two columns
contain information about the results of the time series analysis.
Column 10 gives the RMS of the CA lightcurve for targets No 1-52 and
the RMS of the TLS lightcurve for all others. The last column
indicates whether the target is classified as variable (v) and/or
periodically variable (p). For a few objects, time series analysis was
not possible, because they are either too faint or too bright in most
of the images.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table7.dat 76 135 Coordinates and photometry of cluster member
candidates in the sigma Ori cluster
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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- 3 I3 --- Seq Identification number
6 I1 h RAh Right ascension (J2000)
8- 9 I2 min RAm Right ascension (J2000)
11- 15 F5.2 s RAs Right ascension (J2000)
17 A1 --- DE- Declination sign
18 I1 deg DEd Declination (J2000)
20- 21 I2 arcmin DEm Declination (J2000)
23- 26 F4.1 arcsec DEs Declination (J2000)
28- 29 A2 --- Src *[ct ] Identified with TLS (t) and/or CA (c) data
31- 35 F5.2 mag Rmag ? R-band photometry
37- 41 F5.2 mag Imag I-band photometry
43- 47 F5.2 mag Jmag J-band photometry (from 2MASS)
49- 53 F5.2 mag Hmag H-band photometry (from 2MASS)
55- 59 F5.2 mag Ksmag Ks-band photometry (from 2MASS)
61 A1 --- l_Mass Limit flag on Mass
62- 65 F4.2 solMass Mass Mass estimate
67- 71 F5.3 mag RMS *? Lightcurve RMS.
73- 74 A2 --- Var [vp ] Variable (v) and/or periodic variable (p)
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Note on Src:
t = identified from 2m Schmidt telescope of the
Thuringer Landessternwarte Tautenburg (TLS)
c = identified from the 1.23m telescope on Calar Alto (CA)
Note on RMS:
RMS of the Calar Alto lightcurve for targets No 1-52 and the RMS of
the Thuringer Landessternwarte Tautenburg (TLS) lightcurve for all
others.
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Acknowledgements: A. Scholz
(End) Patricia Bauer [CDS] 05-Mar-2004