J/PASP/121/1188 Periodic variables in NGC 2301 (Sukhbold+, 2009)
Periodic variables and gyrochronology in the open cluster NGC 2301.
Sukhbold T., Howell S.B.
<Publ. Astron. Soc. Pac., 121, 1188-1204 (2009)>
=2009PASP..121.1188S 2009PASP..121.1188S
ADC_Keywords: Clusters, open ; Stars, variable ; Photometry, UBVRI ;
Photometry, CCD
Abstract:
We present the results of a search for periodic variables within 4078
time-series light curves and an analysis of the period-color plane for
stars in the field of the open cluster NGC 2301. One hundred
thirty-eight periodic variables were discovered, of which five are
eclipsing binary candidates with unequal minima. The remaining 133
periodic variables appear to consist mainly of late-type stars whose
variation is due to rotation modulated by star spot activity. The
determined periods range from less than a day to over 14 days and have
nearly unreddened B-R colors in the range of 0.8 to 2.8. The Barnes
(2003ApJ...586..464B 2003ApJ...586..464B) interpretation of the period-color plane of late
type stars is tested with our data. Our data did not show distinct I
and C sequences, likely due to nonmember field stars contaminating in
the background, as we estimate the total contamination to be 43%.
Using different assumptions, the gyrochronological age of the cluster
is calculated to be 210±25Myr, which falls in the range of age
values (164-250Myr) determined by previous studies. Finally, we
present evidence which nullifies the earlier suggestion that two of
the variable stars in NGC 2301 might be white dwarfs.
Description:
In this article, we present the results of an analysis of the 140
variable stars, from the 4078 discussed in Howell et al.
(2005PASP..117.1187H 2005PASP..117.1187H) and Tonry et al. (2005PASP..117..281T 2005PASP..117..281T).
Observations of NGC 2301 were made for each first half-night of 12
nights in a row (2004 February 11-22) at the University of Hawaii 88
inch (2.2m) telescope atop Mauna Kea.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 53 133 The 133 additional periodic variables
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Name Variable name
(<Cl* NGC 2301 HVT "Name"> in Simbad)
7- 14 F8.4 deg RAdeg Right ascension in decimal degrees (J2000)
16- 23 F8.6 deg DEdeg Declination in decimal degrees (J2000)
25- 31 F7.4 d Per Period
33- 40 E8.3 mag Ramp Amplitude in R band
42- 47 F6.3 mag Rmag R magnitude
49- 53 F5.3 mag B-R B-R colour index
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History:
From electronic version of the journal
References:
Tonry et al., Paper I 2005PASP..117..281T 2005PASP..117..281T
Howell et al., Paper II 2005PASP..117.1187H 2005PASP..117.1187H
(End) Patricia Vannier [CDS] 18-Oct-2010