Discovery of a second outbursting hyperluminous X-ray source

Understand

We report on six Chandra and one HST/WFC3 observation of CXO J122518.6+144545, discovered by Jonker et al.

• (2010) as a candidate hyperluminous X-ray source (HLX), X-ray bright supernova or recoiling supermassive black hole at $L_X = 2.2 \times 10^{41}$ erg/s (if associated with the galaxy at 182 Mpc).
• We detect a new outburst of the source in a Chandra image obtained on Nov 20, 2014 and show that the X-ray count rate varies by a factor $> 60$.
• New HST/WFC3 observations obtained in 2014 show that the optical counterpart is still visible at $g' = 27.1 \pm 0.1$, $1 \pm 0.1$ magnitude fainter than in the discovery HST/ACS observation from 2003.