Something has lit up the Cigar Galaxy, astronomers report, and it looks like an exploding star. The increasing brilliance of the supernova has thrilled the stargazing community, potentially becoming a viewing target within reach of binoculars in the next few days.
The brightening supernova appears nestled within the neighboring, edge-on spiral galaxy, Messier 82 (M82), also known as the Cigar Galaxy, which hangs just above the bowl of the Big Dipper. Located about 12 million light-years from Earth, this giant island of stars is a favorite deep-sky target for sky-watchers, viewable with either binoculars or backyard telescopes.
On Tuesday, January 21, students from the urban campus of the University of London Observatory were the first to make the discovery. They noticed a new star, dubbed supernova (SN) 2014J, on an image snapped during a 10-minute viewing session with the school’s 14-inch (35-cm) Celestron telescope.
According to the student discoverers, the whole experience was surreal and caught them off guard.
“One minute we’re eating pizza, then five minutes later we’ve helped to discover a supernova. I couldn’t believe it. It reminds me why I got interested in astronomy in the first place,” said Tom Wright in a statement.
“The chances of finding anything new in the sky is astronomical, but this was particularly astounding as it was one of the first images we had taken on this telescope,” added Ben Cooke.
Spectroscopy reveals it to be a type 1a supernova, which occurs when a white dwarf star continuously draws matter in from a companion star until a tipping point is reached and a runaway nuclear reaction ignites. The explosion brightens quickly. Although many such supernovae are discovered annually, they tend to be much farther away than the Cigar Galaxy.
But now, having discovered this supernova so soon after it detonated, and so close to Earth, the worldwide astronomy community has responded with tremendous activity. Many astronomers are rushing to observe it with the largest telescopes. (Of course, with the supernova and its host galaxy some 12 million light-years away, the actual event took place 12 million years ago and we are only just now seeing its light.)
By catching the explosion so early, astronomers are enjoying a rare opportunity to observe the physical details of a type 1a supernova, which is a variety used as a standard distance marker in studies of the increasing expansion of the universe.
For backyard sky-watchers, SN 2014J also represents an exciting chance to see one of nature’s most violent events unfold before our eyes. At the time of its official discovery it was shining at 11.7 magnitude, and as of January 23 it is at about 11th magnitude (as the magnitude number drops, the star becomes brighter), putting it well within range of small and common telescopes with 6-inch-diameter mirrors.
New reports say that there may have been prediscovery observations that showed the supernova brightening from magnitude 13.9 on the 16th to 12.2 on the 19th. Light curves from similar types of stellar explosions indicate that it may not have plateaued just yet and that it could continue to brighten for the next two weeks, perhaps to magnitude 8, which would put it within the range of binocular viewers.
It is also conveniently located in the early northeastern evening sky for folks in the Northern Hemisphere. To track down SN 2014J, first locate its host galaxy M82, just above the bowl of the Big Dipper (coordinates are right ascension 9h 55m 42.2s, declination +69° 40′ 26″). The supernova itself is just to the side of the galaxy’s bright central core, about 58 arc-seconds southwest. Here’s a more detailed star-finder chart from the American Association of Variable Star Observers (AAVSO).
Check out the growing online gallery of images of the M82 supernova taken by backyard astronomers.
Stay tuned for updates…