J/A+A/492/171 VIc light curves of NGC 6791 V20 (Grundahl+, 2008)
A new standard: Age and distance for the open cluster NGC 6791 from the
eclipsing binary member V20.
Grundahl F., Clausen J.V., Hardis S., Frandsen S.
<Astron. Astrophys. 492, 171 (2008)>
=2008A&A...492..171G 2008A&A...492..171G
ADC_Keywords: Clusters, open ; Binaries, eclipsing ; Photometry
Keywords: open clusters: general - open clusters: individual NGC 6791 -
stars: evolution - stars: binaries: spectroscopic -
stars: binaries: eclipsing - techniques: spectroscopy -
techniques: photometry
Abstract:
We wish to determine accurate ages for open clusters and use this, in
conjunction with colour-magnitude diagrams, to constrain models of
stellar structure and evolution.
The detached eclipsing binary V20 in the old, metal-rich
([Fe/H]=+0.40) open cluster NGC6791 is studied in order to determine
highly accurate masses and radii of its components. This allows the
cluster age to be established with high precision, using isochrones in
the mass-radius diagram. Methods. We employ high-resolution UVES
spectroscopy of V20 to determine the spectroscopic orbit and
time-series V, Ic photometry to obtain the photometric elements.
Description:
V and IC light curves for V20 from CCD observations with the 2.56m
Nordic Optical Telescope (NOT).
Objects:
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RA (2000) DE Designation(s)
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19 20 54.4 +37 45 35 Cl* NGC 6791 KR V20 = V* V568 Lyr
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table11.dat 24 298 Johnson V light curve for V20
table12.dat 24 300 Cousins I light curve for V20
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See also:
J/AJ/129/2856 : Variable stars in NGC 6791 (Mochejska+, 2005)
J/A+A/471/515 : V light curves of NGC 6791 variable stars (De Marchi+, 2007)
Byte-by-byte Description of file: table11.dat table12.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d HJD Heliocentric Julian Date
16- 22 F7.4 mag mag Johnson V or Cousins I magnitude
24 A1 --- Band [VI] Band for magnitude
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Acknowledgements:
Frank Grundahl, fgj(at)phys.au.dk
(End) F. Grundahl [Inst. Phys. & Astr., Aarhus], P. Vannier [CDS] 28-Nov-2008