The symbiotic star HD 4174.

The paper discusses spectroscopic observations, covering the double gamma 5800-6700 region, of the symbiotic star HD 4174. Changes in the equivalent width, radial velocity, and line profile of H(alpha) were observed, and were found to be correlated with a derived pulsation period of 470 days. The data were most consistent with a binary model consisting of an M2 III semiregular variable and a hot secondary surrounded by a common envelope with a temperature of about 10,000 K and an electron density in the range of 0.4 to 3 x 10 to the 5th/cu cm. The circumstellar envelope was found to arise from a mass loss at a rate of about 3 x 10 to the -7th solar mass/yr, driven by isothermal pulsations from the M2 III primary. A weak blue-shifted component of the H(alpha) emission was explained in terms of a stellar wind from the hot component at about 150 km/sec.