Ultraviolet, Optical, Infrared, and Microwave Observations of HR 5110
Linsky, J. L.; Simon, Theodore; Ayres, T. R.; Feldman, P. A.; Little-Marenin, I. R.; Cohen, N. L.; Little, S. J.; Lyons, R.
United States, Canada
Abstract
HR 5110 is a close binary system (P = 2d.6) with the characteristics of an Algol system. Because the primary star is relatively cool (F2 IV) and there is no apparent emission from an accretion disk, the authors were able to detect in IUE spectra the emission of an active chromosphere and transition region of the cooler (K0 IV) secondary. The surface fluxes of the UV emission lines of the K star are similar to those of active RS CVn binaries. The line fluxes appear to vary with orbital phase and are interpreted as emission from an active region on the K star. Two large radio flares were detected. VLBI observations during one of these flares indicated that half the emission came from a region more than 4 times the binary separation.