* Astronomy

Title: The Eclipsing Cataclysmic Variable Lanning 386: Dwarf Nova, SW Sextantis Star, or Both?
Authors: S. Brady (AAVSO), J. R. Thorstensen (Dartmouth), M. D. Koppelman (U. Minnesota), J. L. Prieto (Ohio State U.), P. M. Garnavich, A. Hirschauer, M. Florack (Notre Dame)

We present photometry and spectroscopy of the suspected cataclysmic variable (CV) Lanning 386. We confirm that it is a CV, and observe deep eclipses, from which we determine the orbital period Porb to be 0.1640517 ± 0.0000001 d (= 3.94 h). Photometric monitoring over two observing seasons shows a very active system with frequent outbursts of variable amplitude, up to approx. 2 mag. The spectrum in quiescence is typical of dwarf novae, but in its high state the system shows strong HeII emission and a broad CIV Wolf-Rayet feature. This is unusual for dwarf novae in outburst and indicates a high excitation. In its high state the system shows some features reminiscent of an SW Sextantis-type CV, but lacks others. We discuss the classification of this puzzling object.

Read more (803kb, PDF)