Poster Open Access
F, G, or K-type stars with a white dwarf companion are relatively rarely known systems in comparison to thousands of M stars with white dwarf companions. We have recently studied one of those systems in detail, and found that the sub-components are very rare stars on their own. The UV source in our system turned out to be an extremely hot white dwarf with an effective temperature of 105,000K. The K-type star was found to be chromospherically active and one of the most rapidly rotating sub-giant known (v_rot=151km/s). Here we present the results of our analysis.