Volume 369, Number 3, April III 2001
|Page(s)||908 - 914|
|Section||Interstellar and circumstellar matter|
|Published online||15 April 2001|
Contribution to the search of binaries among Am stars*
II. HD 81976 and HD 98880, double-lined spectroscopic binaries
UMR 5572 d'Astrophysique, Observatoire Midi-Pyrénées -Centre National de la Recherche Scientifique, 14 avenue Édouard Belin, 31400 Toulouse, France
Corresponding author: J.-M. Carquillat, firstname.lastname@example.org
Accepted: 15 January 2001
We present the results of the observations of two Am stars of eighth magnitude, the double-lined spectroscopic binaries HD 81976 and HD 98880, carried out with the CORAVEL instrument at the Observatoire de Haute-Provence in order to determine their orbital elements. We found 1) for HD 81976: days, HJD, , , km s-1, km s-1, km s-1, Gm, Gm, , , and 2) for HD 98880: days, HJD (ascending node), , km s-1, km s-1, km s-1, Gm, Gm, , . The first of these two systems, HD 81976, is formed by two quasi-identical stars, and the Hipparcos data (MV, ) are consistent with late A stars in effective temperature; it is likely that the components rotate synchronised with the orbital motion. A third body may be present in this system since (i) the orbit has a significant eccentricity despite its short period and (ii) the systemic velocity V0 shows a possible drift. For the second system, HD 98880, we give and we propose a simple model based upon Strömgren photometric indices and the HR theoretical diagram of Schaller et al (1992) in addition to orbital parameters and Hipparcos data: K, , , , . The components do not rotate synchronously contrary to HD 81976. Both binaries appear to be detached systems without possibility of eclipses.
Key words: stars: individual: HD 81976, HD 98880 / binaries: spectroscopic / stars: fundamental parameters
© ESO, 2001
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.