KX Andromedae – Deep Sky Collective
KX Andromedae is an interacting binary star system in the constellation Andromeda, about 2,500 light-years away. It consists of a Be star and a smaller companion that is close enough to its partner that gas constantly flows from one to the other, forming an accretion disc around the Be star. That transfer of material is also responsible for the emission lines visible in the Be star’s spectrum.
What makes KX And particularly interesting is its bipolar jets, discovered relatively recently through the Northern Sky Narrowband Survey. The jets extend perpendicularly to the binary system, most likely ionised by the Be star itself and shaped by interaction with the surrounding interstellar medium. Given the system’s distance and the angular size of the jets, each one stretches roughly 19 light-years. For a feature only recently confirmed in the literature, that’s a remarkable scale.
The project
We began imaging KX And in August 2025 and collected data for just over three months, followed by a month of processing. 11 contributors were involved across photography, stacking, and editing roles. Total integration came to 691 hours and 11 minutes, with around 240 hours each in Ha and OIII and the remainder in LRGB.
The decision to focus solely on Ha and OIII was deliberate, trading breadth for signal depth in those two channels. In hindsight SII would have been worth adding, but the tradeoff produced clean results in the wavelengths we prioritised.
What the data revealed
The Ha data confirmed the full jet stream as seen in previous images of the region, but also picked up the outer Ha shell in what we believe to be its full extent. Earlier images had hinted at this shell but lacked the signal to show it clearly.
The bigger surprise came from the OIII. No previous image had gone deep enough to show definitive structure in that channel, but with 240 hours behind it, our dataset confirmed the existence of an extensive outer OIII shell. It closely matches the Ha shell in many areas, with two notable differences: it lacks the small-scale structures visible in Ha, and it extends further, particularly in the southern jet.
Three versions
The dataset was processed independently by three editors, with no sharing of results between them. Steeve Body’s edit is the main published version, with Nicolas Puig’s version (including Ha background treatment) and Alpha Zhang’s edit also available.
Integration
Ha: 240h+ / OIII: 240h+ / LRGB: remainder / Total: 691h 11m
Credits
Tim Schaeffer (coordination and photography), Carl Björk (stacking and photography), Steeve Body (editor), Nicolas Puig (editor and photography), Alpha Zhang (editor and photography). Photographers: Akash Jain (192h contributed), Brian Valente (100h+), Jasper Capel, Ryan Wierckx, Stephen Guberski, Jim Matzger.
Full image at https://deepskycollective.com/gallery.