SPECTROSCOPIC BINARY ORBITS FROM PHOTOELECTRIC RADIAL VELOCITIES PAPER 223: HR 396, HR 7477, HR 7636, AND 6 ANDROMEDAE

HR 396 is a G8 subgiant in an 84-day almost-circular orbit. In addition to the orbital motion, its radial velocities since 2002 have shown a slow but steady upward trend of about O.I7 km s(-1) per thousand days; the trend can be traced back 40 years. The Cambridge work on the star has, however, been largely pre-empted by much more precise radial velocities obtained by a large syndicate that is observationally based at Lick Observatory. The other three stars have orbital periods of the order of a decade and orbits of moderate eccentricity. HR 7477 is widely supposed to be of type G6 V - hard to believe in the light of M-V similar to +O(m.)7 and (B - V) = I(m.)O2. HR 7636 is of type G8III, while 6 And has been classified F-5 IV but has no more than main-sequence luminosity. 6 And has a considerable rotational velocity (upsilon sin i similar to I9 km s(-1)) and a mass function of O.2 M-circle dot that is probably to be understood in terms of duplicity of the secondary.