SPECTROSCOPIC BINARY ORBITS FROM PHOTOELECTRIC RADIAL-VELOCITIES - PAPER-128 - 24-AQUARII

24 Aquarii is a close visual binary which has long been under suspicio n of being a triple system. That suspicion, although based upon eviden ce that now appears dubious, proves to be correct: we show, from a gen erous number of Coravel radial-velocity observations, that the visual primary is a single-lined spectroscopic binary. It has a period of 5.8 84 days and an orbit whose small eccentricity is probably maintained b y the visual secondary. Our observations are consonant with the visual orbit published by Danjon in 1942, which has a period of nearly 50 ye ars and a very high eccentricity. Unfortunately it will be 25 years be fore a periastron passage can be witnessed. There is a distant visual companion which appears on astrometric grounds to be optical, although its radial velocity is identical with that of the close pair.