It is rare for MagAO to carry out extragalactic observations because suitable natural guide stars are hard to find.
But this time we have got some luck. A week ago (February 8), a bright supernova, SN 2016adj, appeared in the active galaxy NGC 5128 (Centaurus A). Classified as Type IIb, its progenitor is believed to be a very massive star in a binary system, undergoing a significant mass loss before explosion. However, direct identification of the progenitor remains challenging, even though astronomers have been constantly detecting supernovae in imaging surveys.
Since SN 2016adj is only 4″ from a bright foreground star, it is an ideal target for our visible AO camera. Prompted by Prof. Nathan Smith, we used MagAO to observe the supernova on February 13, and successfully took ~2 hr deep exposures at 0.9 micron. Comparing the new MagAO image to archival HST and VLT data, we and our collaborators were able to identify a possible progenitor star. Notably, this is the 5th Type IIb progenitor identified in pre-explosion images over the past 20 years.
Yesterday we posted our results on the Astronomer’s Telegram. You can find the link here: