The Red River

KX Andromedae is an interesting binary star system composed of a B3 -type primary star and a cool K1III giant companion. The secondary star, which has roughly half the mass of the primary, is believed to be overflowing its Roche lobe and transferring material onto the primary. Some of this in-falling gas is ejected in the form of jets that emerge perpendicular to the system’s accretion disk. These jets are ionized by the radiation from the primary star, but only very faintly in H-alpha wavelength. Because of the very faint emission KX And is rarely imaged by amateur astronomers. Also relatively little information about the properties of these jets is available online. Current estimates place the jets at a length of 19 light-years. The binary itself is about 25 million years old, and the cool giant completes a nearly circular orbit around the primary approximately every 39 days. I have imaged this target for the past three months, acquiring 25 hours of H-alpha data and 1.5 hours for the surrounding starfield in RGB with my 250mm f/4.7 Newtonian telescope. The object is invisible in single 10 minute exposures, but stacking and careful processing of background gradients reveals this hidden red river among the stars.