EXOSAT X-ray and Optical Observations of the X-ray Source EXO 020528 + 1454.8 = G 035 - 027
Richter, G. A.; Hudec, R.; Wenzel, W.; Hacke, G.; Tremko, J.; Mrkos, A.; Gvetz, W.; Huth, H.; Lovas, M.; Peřestý, R.; Valniček, B.
Czech Republic, Austria, Hungary
Abstract
Results of the Exosat X-ray observations and quasi-simultaneous optical photographic photometry of the X-ray source EXO 020528 + 1454.8 = 1 E 0205 + 149 are presented and discussed. The results indicate that the source is identical to the Lowell proper motion object G 035 - 027, a pair in which at least one but more probably both members are dMe flaring stars. The integral X-ray luminosity is between about 1.8 x 10 to the 28th and 5.3 x 10 to the 29th erg/s for the pair or about 9 x 10 to the 27th to 4 x 10 to the 28th erg/s for each component. The object shows a soft X-ray spectrum with a blackbody temperature of about 10 to the 6th K, X-ray variability of a factor of about three over time intervals of months to years, X-ray to bolometric luminosity ratio of about 0.0001 to 0.001 indicating flaring activity, and possible optical flares with amplitudes of the order of one magnitude or larger in B on at least one component of the star system.