2009ApJ...701...12L

We report the discovery of a flaring X-ray source with an optical counterpart with Hα emission and red-excess, in the direction of the Small Magellanic Cloud. A 100 ks X-ray observation with Chandra detected a flare lasting ∼6 ks in the source CXO J005428.9-723107. The X-ray spectrum during the flare was consistent with a thermal plasma of temperature kT = 2.4±0.4 keV. In quiescence following the flare the spectrum was softer (kT ∼ 0.4 keV). Timing analysis did not reveal any significant periodicities or quasi-periodic oscillations. Optical images taken with the Magellan-Baade 6.5 m telescope show a single star in the (0".9) error circle. This star has apparent magnitude V = 19.17, exhibits enhanced Hα emission (Hα - r = -0.88±0.02), and has a large proper motion. Alternative explanations are explored, leading to identification as a relatively nearby (Galactic) coronally active binary star of the BY Draconis class.