The Astronomer's Telegram number 9211
http://www.astronomerstelegram.org/?read=9211
describes a possible new supernova in the galaxy NGC 4725. This galaxy is relatively nearby, at a distance of only about 13 Mpc, so if the new object does turn out to be a supernova, it will be one of the brightest of the year. It could peak at magnitude V=12 or so, likely brighter than the SN 2016coj in NGC 4125.
There is the chance that this is not a supernova, but some sort of very luminous variable star, so keep watching the Astronomer's Telegrams for confirmation. I'll be taking some images tonight to see what I can see. If this _is_ a supernova, it's likely to be young, and so frequent observations over the next few weeks will be very important.
The galaxy is reasonably well placed for observers in the northern hemisphere, who can see it in the evening skies until some time after midnight. If you are looking for a good, challenging project for the summer, this could be it!
Michael Richmond
As Astronomer's Telegram 9214 points out,
http://www.astronomerstelegram.org/?read=9214
the object is not a supernova in NGC 4725, but the minor planet Makemake.
And how many times have folks fallen for this boo-boo ;)
What I find really interesting is comparing the side-by-side POSS-II plate with the ASSAS-SN image. One is made with a 48" aperture and Kodak IIIa-J photographic film, the other with a 5.5" aperture and CCD, and they look almost identical, really amazing.
Mike