Contribution à l'étude des binaires des types F, G, K, M. VII. HD 147395, une géante M binaire spectroscopique

Observatoire Midi-Pyrénées, Laboratoire d'Astrophysique de Toulouse (U.R.A. No. 285 du C.N.R.S.), 14 Avenue Edouard Belin, F-31400 Toulouse, France

Send offprint request to: J.M. Carquillat

Received: 23 October 1995
Accepted: 27 November 1995

Abstract

HD 147395, a giant M2 star, was found to be a spectroscopic binary by the Mount Wilson astronomers some time ago, but its orbit remained unknown so far. Radial velocity observations carried out at the Observatoire de Haute-Provence with the CORAVEL spectrovelocimeter permitted us to obtain the orbital elements of this binary. They are as follows: P = 335.537 days; T = 4448335.0 JD; ω = 336.9°; e = 0.235; K = 16.87 km/s; V₀ = -20.12 km/s; a₁sini = 75.67 Gm; =0.154 . The spectral type of the primary, and the value, lead to M₂ ≥ 1.0±0.2 for the mass of the unseen companion. According to the color indices and of the system, the secondary star should be a F5V. We estimate at 1.25±0.1 UA the mean linear separation of the components; nevertheless, both the distance of this binary (275 pc) and the expected value of seem too important for the system to be resolved by interferometry.