The Astronomical Journal
We have obtained phase-resolved spectroscopy (3660-6040 Å) of the recently discovered cataclysmic variable EUVE J21 15-586 using the 74-inch telescope at Mount Stromlo Observatory. The radial velocity is modulated over a period of 110.8 min with a possible one-cycle-per-day alias of 102.8 min, and a semiamplitude of ≍270 km s-1 at Hβ and ≍390 km s-1 at He II λ4686. The spectroscopic appearance (H I Balmer, Ca II, He I, He II emission lines), the orbital period, and the velocity amplitude indicate that this cataclysmic variable is probably an AM Her type; the absence of cyclotron humps indicates a low intensity magnetic field (B<20 MG). Extreme ultraviolet emission phased at the orbital period shows evidence of variability, but additional EUV/soft x-ray observations are recommended.
Vennes, Stephane; Wickramasinghe, Dayal T.; Thorstensen, John R.; Christian, Damian J.; and Bessell, Michael S., "On the Orbital Period of the New Cataclysmic Variable EUVE J2115-586" (1996). Open Dartmouth: Faculty Open Access Articles. 2124.