J/A+A/463/579 Geneva photometry of HD 23642 (Groenewegen+, 2007)
The Pleiades eclipsing binary HD 23642 revisited.
Groenewegen M.A.T., Decin L., Salaris M., De Cat P.
<Astron. Astrophys. 463, 579 (2007)>
=2007A&A...463..579G 2007A&A...463..579G
ADC_Keywords: Binaries, eclipsing ; Photometry, Geneva
Keywords: stars: distances - binaries: eclipsing - stars: individual: HD 23642 -
stars: fundamental parameters -
open clusters and associations: individual: Pleiades
Abstract:
HD 23642 is the only known eclipsing binary in the Pleiades, and
therefore of importance in determining the distance to this cluster.
To use new photometric and spectroscopic data in combination with
existing data in the literature in order to improve the determination
of the parameters of the system, its distance and reddening.
New photometric and spectroscopic data are presented for HD 23642. The
spectroscopic data are ``spectrally disentangled'' using the KOREL
code. The new and literature photometric and radial velocity data are
simultaneously analysed using the FOTEL code to obtain the orbital
solution and derive the fundamental parameters of the two stars. The
distance and reddening are determined by fitting 7-colour Geneva,
B,V and Stroemgren colours, and considering surface-brightness
relations for the two components in (B-V) and Stroemgren c1-index.
The preferred distance is 138.0±1.5pc for a reddening of
E(B-V)=0.025±0.003. The reddening value is larger than the 0.012
adopted in the recent works on this stars by Munari et al.
(2004A&A...418L..31M 2004A&A...418L..31M) and Southworth et al. (2005A&A...429..645S 2005A&A...429..645S), and
smaller than other values in the literature for the cluster reddening.
The distance is in agreement with other recent works on the distance
to the Pleiades.
A comparison with evolutionary models suggests that the inclusion of
convective core overshoot gives a much better fit to the empirical
mass-radius relationship obtained from the binary analysis. Both this
comparison and the "spectral disentangling" are consistent with
HD 23642 having [Fe/H]=+0.06, a value determined by the most recent
spectroscopical analyses of Pleiades stars.
Description:
Table 3 contains the photometric data in the Geneva system. Listed
are: HJD, a quality flag (see Rufener, 1988A&A...206..357R 1988A&A...206..357R), and, V,
U-B, V-B, B1-B, B2-B, V1-B, G-B.
Objects:
---------------------------------------------
RA (2000) DE Designation(s)
---------------------------------------------
03 47 29.5 +24 17 18 HD 23642 = HIP 17704
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 57 211 Geneva photometry
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d HJD Heliocentric Julian date
15 I1 --- Qual [2/4] Quality flag for photometry
(see Rufener 1988A&A...206..357R 1988A&A...206..357R)
17- 21 F5.3 mag Vmag Geneva v magnitude
23- 27 F5.3 mag U-B Geneva u-b colour index
29- 33 F5.3 mag V-B Geneva v-b colour index
35- 39 F5.3 mag B1-B Geneva b1-b colour index
41- 45 F5.3 mag B2-B Geneva b2-b colour index
47- 51 F5.3 mag V1-B Geneva v1-b colour index
53- 57 F5.3 mag G-B Geneva g-b colour index
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Acknowledgements:
M.A.T. Groenewegen, groen(at)ster.kuleuven.be
(End) M.A.T. Groenewegen [KU Leuven], Patricia Vannier [CDS] 07-Nov-2006