J/A+A/426/247 HD 173977 uby photometry and HRV (Chapellier+, 2004)
HD 173977: an ellipsoidal delta Scuti star variable.
Chapellier E., Mathias P., Garrido R., Le Contel J.-M., Sareyan J.-P.,
Ribas I., Parrao L., Moya A., Pena J.H., Alvarez M.
<Astron. Astrophys. 426, 247 (2004)>
=2004A&A...426..247C 2004A&A...426..247C
ADC_Keywords: Stars, variable ; Radial velocities ; Photometry, uvby
Keywords: stars: binaries: general - stars: oscillations -
techniques: photometric - techniques: spectroscopic -
stars: variables: delta Scuti
Abstract:
We present spectroscopic and photometric observations of the star
HD 173977. It appears that the star is part of a double line binary
system, with a period of 1.801d, corresponding to twice the period of
the photometric variations. Hence the star is an ellipsoidal variable.
The system is probably synchronized. The physical parameters of both
components were derived through two independent methods, one based on
evolutionary tracks, the other being the result of the behaviour of
light curves in a close binary system. After removing the ellipsoidal
variations, 3 frequencies are detected in the photometric data: 8.56,
14.51 and 16.42d-1, while 2 additional frequencies are also possible:
10.96 and 12.11d-1.
In accordance with its position in the HR diagram, the primary
component of HD 173977 should be considered as a delta Scuti star
and no longer as a gamma Doradus star. In addition, HD 173844, used
as a check star, is discovered variable with a 15.79d-1 frequency
and is classified as a delta Scuti star.
Description:
Spectroscopic observations were obtained at the Observatoire de
Haute-Provence (France) with the AURELIE spectrograph attached to the
Coude focus of the 1.52m telescope. We obtained 35 spectra spread
over 416 days from August 2001 to October 2002.
Photometric observations were obtained in August and September 2001 at
the 0.9 photometric telescope of the Sierra Nevada Observatory (Spain)
and at the 1.5m telescope at San Pedro Martir Observatory (Mexico).
Objects:
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RA (2000) DE Designation(s)
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18 44 53.1 +57 05 17 HD 173977 = HN Dra = HIP 91983
18 43 08.7 +56 49 59 HD 173663 = PPM 36794 (comparison)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 26 29 Radial velocity data for the star and its companion
table2.dat 33 211 Photometric data (HD 173977 - HD 173663) in
Stroemgren filters
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD Heliocentric Julian date
14- 19 F6.1 km/s HRV1 ?=999.9 Heliocentric radial velocity of component 1
21- 26 F6.1 km/s HRV2 ?=999.9 Heliocentric radial velocity of component 2
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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- 12 F12.4 d HJD Heliocentric Julian date
14- 19 F6.3 mag vmag Stroemgren differential v magnitude
21- 26 F6.3 mag bmag Stroemgren differential b magnitude
28- 33 F6.3 mag ymag Stroemgren differential y magnitude
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Acknowledgements: Philippe Mathias
(End) Patricia Vannier [CDS] 19-Jul-2004