A. R. Taylor and P. C. Gregory, Physics Department, University of British Columbia, report that the radio emission of this object (cf. IAUC 3170, 3180) varies in a periodic fashion with a period of 26.45 +/- 0.05 days, based on observations over two years at N.R.A.O. (5 GHz) and A.R.O. (10 GHz). At phase 0.3 (1978 Feb. 21) the radio emission at both 5 and 10 GHz is ~ 15 mJy. Maximum occurs at phase 0.65 and is typically 200 mJy. Radial-velocity measurements by J. B. Hutchings and D. Crampton, Dominion Astrophysical Observatory, of H and He I absorptions in the optical spectrum indicate an orbital amplitude of K = 15 +/- 4 km/s if the period is 26.45 days. This yields a mass function of 0.0093, which implies secondary masses between 1.0 and 1.9 Msol for primary masses of 10-20 Msol and inclination > 60o. The phase of maximum positive velocity coincides with the phase of radio minimum. The general appearance of the spectrum has not changed appreciably over two years.
International Astronomical Union Circular
- Pub Date:
- March 1980