Observations of hydrogen deficient binary Upsilon Sagittarii

Abstract

The absolute magnitude M(v) of the hydrogen deficient binary Upsilon Sgr has been estimated as -4.8 + or - 1.0 from the distribution of the interstellar reddening, polarization, and interstellar lines of the surrounding stars. From the ANS observations obtained at the time of the secondary eclipse, it appears that the hotter secondary is surrounded by a disk with colors of a B8-B9 star. The lambda 1550 C IV absorption line arising in the stellar wind does not show any change in strength during the secondary minimum. The upper limit to the mass-loss rate from the high temperature wind is estimated as not greater than 5 x 10 to the -7th solar mass/yr from the 2 cm and 6 cm radio observations.