Description
Explosive accreting transients like Cataclysmic Variables and Low-Mass X-ray Binaries can leap several magnitudes in brightness during their frequent outbursts. Many sources are well-studied both at their explosive ~15th magnitude heights and their quiescent flickering as faint as 20th mag. But what if we went fainter?
There are a hidden population of transients that are too far away to be seen by most of our surveys in their quiescent state, save for when they peek into our detectable range during outbursts. Here is where BlackGEM, a new optical telescope at La Silla, Chile, has proved valuable; its continuous sky-scanning work, reaching below 20th magnitude, is able to capture these distant, unknown objects at the height of their luminosity, before they fall back into obscurity.
In this talk, I will present the result of several months of BlackGEM monitoring of these 'hostless' or 'orphaned' accreting transients. I will go over those that have been discovered so far, what a combination of monitoring telescopes, sky surveys, and spectra can tell us about them, and what these results mean for the population in general.
