EXOSAT / Optical Observations of the Am-Herculis Star H0139-68
Motch, C.; Beuermann, K.; Schwope, A.; Weissieker, H.
Germany, France
Abstract
We report preliminary results of X-ray and optical observations of the AM Her star HO139-68 during its low state at V ∼ 17 to 18. X-rays were detected only during ∼ 45 % of the orbital period when the system was optically bright and the radial velocity of the Balmer lines was positive. Our data show no evidence for accretion onto two active poles as indicated by previous X-ray and linear-polarization measurements. We find that the distance of the system based on its K-magnitude is d ∼ 130 pc.