Stellar surface phenomena - Stellar rotation and the BY Draconis syndrome in the high-eccentricity binary BD+24 deg 692

Abstract

view Abstract Citations (21) References (11) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Stellar surface phenomena: stellar rotation and the BY Draconis syndrome in the high-eccentricity binary BD +24 692. Bopp, B. W. ; Noah, P. V. ; Klimke, A. Abstract The double-line spectroscopic binary (SB2) BD+24 deg 692 (sp. dK3) is found to be a BY Draconis variable, showing a light variation of about 0.1 mag owing to spots on the rotating stellar surface. The rotation period, 6.82 days, differs markedly from the orbital period of 11.93 days. The discovery of high surface activity on essentially all dK-dM SB2 stars supports the hypothesis that rotation with v(equator) not less than 5 km/s is the underlying cause of the BY Dra syndrome. The two high-eccentricity BY Dra SB2 systems (BD+24 deg 692 and BY Dra itself) do not exhibit synchronism. An examination of the synchronization time from tidal effects implies that BY Dra is surprisingly young, in support of Vogt and Fekel's (1979) arguments that BY Dra is in the last stages of pre-main-sequence evolution. Publication: The Astronomical Journal Pub Date: October 1980 DOI: 10.1086/112811 Bibcode: 1980AJ.....85.1386B Keywords: Binary Stars; Stellar Rotation; Stellar Spectrophotometry; Variable Stars; Eccentricity; Stellar Evolution; Astronomy full text sources ADS | data products SIMBAD (6)