I am surprised that more people haven't commented on this. If you haven't done so already, check it out and take a moment to read the full paper on this discovery:
http://arxiv.org/pdf/1509.03622v1.pdf
Followup investigation using ground-based instruments has ruled out almost all of the usual possibilities, mainly due to the lack of IR emissions typical in such cases and there is a great deal of interest for ongoing monitoring.