Ellipticity and Starspots in the RS CVn Binary HD 185151 = V1764 CYG

February 1987 • 1987AJ.....93..430L

Authors • Lines, H. C. • Lines, R. D. • Kirkpatrick, J. D. • Hall, D. S.

Abstract • The variable star HD 185151 = V1764 Cygni is a chromospherically active K2 III spectroscopic binary. Analysis of six years of photometry in the V bandpass, previously published, reveals three distinct variabilities. The largest amplitude results from the ellipticity effect, which has a period of 20d.0665±0d.0044 and an amplitude of 0m.125±0m.004. The second variation is caused by starspots and has a period of 39d.878±0d.036. Its amplitude changes from year to year, ranging from 0m.022 to 0m.092 over the six year observing interval. The migration period of the starspot wave, relative to the orbital period of 40d.1330±0d.0088, is about 17 yr. There is also a third variability, changes from year to year in the mean magnitude of this starspot wave. The mean covers a range of about 0m.04 but may not do so periodically. Searches for a possible reflection effect and for eclipses prove negative.


IPAC Authors


Davy Kirkpatrick

Senior Scientist