Wed, 22 Jan 2014
Supernova in M82 still bright
A relatively close supernova has exploded in the galaxy Messier 82 and may become bright enough to be observed in binoculars. M82 lies about 11.4 million light-years away, which is relatively nearby, making this already one of the brightest for many years. And the discovery was made from the light-polluted suburbs of London.
Update 13 February
The supernova is still easily visible with the right equipment, though it is not bright enough to be seen with typical binoculars. The photo at right was taken at 01.40 on 13 February using an 80 mm refractor and Atik 314L+ CCD camera, and shows the supernova at about magnitude 11.
Update 29 January
The supernova is now reported to be at magnitude 10.2, and is visible with quite small instruments, though you need a magnification of about 75 to see it easily. Now read on...
Early images show the supernova as a bright blob against the cigar shape of the galaxy, which can be found in the constellation of Ursa Major and which is visible as a smudge in binoculars or a small telescope.
Estimates of its brightness put it at a little above 12th magnitude, so it is a telescopic target. However, supernova experts say it was discovered early in its explosive outburst and so could reach magnitude 8.
The galaxy M82 is easy to find using the familiar star pattern of the Big Dipper (also known as the Plough) which is part of the constellation of Ursa Major. Just imagine a line extended through the stars gamma and alpha and it will point to where the galaxy lies.
An image of the supernova (above) was taken by SPA member Robin Scagell, remotely using a telescope in New Mexico.
The supernova was first reported on Tuesday night by tutor Dr Steve Fossey and his students, of University College London, when they imaged the galaxy from the university’s teaching observatory at Mill Hill, north London.
It was confirmed by Russian astronomers L Elenin and I Molotov, using a 0.4-metre telescope at the ISON-NM Observatory at Mayhill, New Mexico. Its position is measured as 09h 55m 42s, +69d 40’ 25.8”, and the discovery brightness was given as magnitude 11.7. The object has now been given the official designation SN 2014J.
Remarkably, pre-discovery images have turned up showing that the supernova was already apparent a week before discovery as it brightened. But somehow it went unnoticed.
News of the supernova spread swiftly thanks to social media such as Twitter, with excited professional astronomers comparing notes to help themselves understand its significance! They will also be scouring old Hubble images to see if they can see the star that produced the supernova.
A chart shows the location of M82 in the mid-evening sky from the UK. Credit: Robin Scagell
The SPA’s Tony Markham, a formidable variable star observer, said: “At its latest reported magnitude of 11.7, a telescope will be needed to see the supernova. However given that it seems to have been detected in its early stages it may well brighten further and could even become visible in good binoculars.”
Chris Lintott, of the University of Oxford, and presenter of The Sky at Night, told us: “This is a nearby supernova, by astronomical standards, and so we have the chance to learn about the causes and processes that drive these spectacular events. Early indications are this might be a type Ia - they’re the type we use to measure the expansion of the Universe and so that would be especially exciting.”
The closest supernova of recent years was seen to explode in 1987 in the Milky Way’s companion galaxy the Large Magellanic Cloud. Labelled SN1987A, it was of a different type to the new supernova, and reached magnitude 3 though was too far south for UK observers to see.
Pre-discovery images by UK observers are now being examined. Stephen Harrison of Lichfield. Staffs, writes:
I took this image on 19 January at 23:26.
I have been a member of the SPA since the early 1980’s and have recently returned to my hobby full time. I was just trying out my new permanent mount I have set up, seeing how long I could take unguided exposures as I have not yet bought a guide camera.
When I received the newsletter with the discovery of the supernova, I decided to check my pictures for that night. As you can see there is the supernova.
It goes to show that you should check even if only taking test shots!
A cropped version of Stephen's original photo, which also shows M82.
Added by: Paul Sutherland