Spectroscopy of V341 arae: A nearby nova-like variable inside a bow shock Nebula

V341Arae is a 10th-magnitude variable star in the southern hemisphere, discovered over a century ago by Henrietta Leavitt, but relatively little studied since then. Although historically considered to be a Cepheid, it is actually blue and coincides with an X-ray source. The star lies near the edge of the large, faint Hα nebula Fr2–11, discovered by D.Frew, who showed that V341Ara is actually a cataclysmic variable (CV). His deep imaging of the nebula revealed a bow-shock morphology in the immediate vicinity of the star. We have carried out spectroscopic monitoring of V341Ara, and we confirm that it is a nova-like CV, with an orbital period of 0.15216days (3.652 hr). We show that V341Ara is remarkably similar to the previously known BZCam, a nova-like CV with a nearly identical orbital period, associated with the bow shock nebula EGB4. Archival sky-survey photometry shows that V341Ara normally varies between V≃10.5 and 11, with a characteristic timescale ranging from about 10 to 16 days. V341Ara lies well off-center within Fr2–11. We speculate that either the star is undergoing a chance high-speed encounter with a small interstellar cloud, or that the nebula was ejected from the star itself in a nova outburst in the fairly distant past. At a distance of only 156pc, V341Ara is one of the nearest and brightest known nova-like variables, and we encourage further studies.