We report the discovery of activity emanating from Centaur 2014 OG392. Centaurs orbit between Jupiter and Neptune, thus they are both faint and cold; 2014 OG392 orbits between 10–15 au where its equilibrium temperature would be around 60 K. Active Centaurs are poorly understood in large part because fewer than 20 have been discovered to date. We initially found suspected activity via a database search algorithm we developed to locate images of 2014 OG392 in the archival images from the Cerro Tololo Inter-American Observatory Blanco 4 m telescope Dark Energy Camera (DECam). We carried out a follow-up observing campaign with the DECam, the Las Campanas Observatory 6.5 m Walter Baade Telescope, and the 4.3 m Lowell Discovery Telescope.
We developed a novel technique which combines observational measurements (e.g., color, dust mass) and modeling efforts (e.g., volatile sublimation, orbital dynamics) to ascertain the species most likely responsible for observed activity. For 2014 OG392 these molecules are CO2 and/or NH3; both ices are optically neutral, yet we found 2014 OG392 to be roughly one magnitude redder than the Sun in B-R, so the reddening agent is as yet unknown.
This material is based upon work supported by the NSF Graduate Research Fellowship Program under grant No. 2018258765 to COC.