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 20^d.0665±0^d.0044 and an amplitude of 0^m.125±0^m.004. The second variation is caused by starspots and has a period of 39^d.878±0^d.036. Its amplitude changes from year to year, ranging from 0^m.022 to 0^m.092 over the six year observing interval. The migration period of the starspot wave, relative to the orbital period of 40^d.1330±0^d.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 0^m.04 but may not do so periodically. Searches for a possible reflection effect and for eclipses prove negative.

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• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=1987AJ.....93..430L
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• ARTICLE http://articles.adsabs.harvard.edu/full/1987AJ.....93..430L?defaultprint=YES