A cosmic celebrity gets some superstar treatment! This week while patrolling the night sky with their telescopes two French backyard astronomers independently managed to snag digital images of a supernova explosion caught in the act – with all the action occurring within the Whirlpool galaxy 31 million light years away.
On May 31st one amateur noticed a new star embedded within one of the spiral arms of the distant galaxy where there wasn’t any before. By the next evening other amateur stargazers and robotic supernova patrol telescopes clued in as well and the alarm was sounded to the worldwide observing community. Sky and Telescope website is reporting that professional astronomers are scouring through images of the Whirlpool from international observatories including the Hubble space telescope taken weeks and even years before the supernova became visible to see what the precursor star might have looked like before it blew up. This will help us gain critical insight into the inner clockwork of these titanic event that are ranked as some of the most powerful forces in the universe.
Called a Type II Supernova, this new discovery is a member of an elite stellar club of heavyweights -supergiant stars at least 10 times larger than our sun that completely destroy themselves when they reach the end of their lives. Astronomers believe that a supernova explosion occurs about once a century in all spiral galaxies. However this galaxy appears to be testing that theory since this will be the third such stellar detonation to occur in the same galaxy in just 17 years!
The Whirlpool lives up to its name as a real showpiece in large aperture telescopes under dark skies. Known also as M 51, it was first observed by comet sleuth Charles Messier back in 1773 and was the first galaxy where a definite spiral structure was seen.
While you shouldn’t expect picturesque views of those spiral arms – a la Hubble – it’s just about visible through suburban binoculars which will pick up the nucleus as a faint, tiny smudge. Meanwhile hints of sweeping spiral arms hugging a bright central core can be glimpsed with medium sized telescopes (6 to 8 inches) under dark sky conditions. Careful observation also reveals a much smaller and dimmer companion galaxy that appears to be interacting with one of the Whirlpool’s spiral arms.
Being relatively bright and within reach of the average telescope owner - it’s no wonder that the 60,000 light year wide Whirlpool is a popular ‘must-see’ deep- sky target for stargazers. Even though detailed views may be challenging, the ’wow’ moment for observers is simply the fact that this distant object can be glimpsed with the human eye.
For those in the Northern Hemisphere, its perfectly positioned in the evening night sky to hunt down this time of the year. You’ll find the galaxy located just off the handle of the famous Big Dipper pattern of stars within the constellation Canes Venatici.
What about seeing the supernova? The star is way too faint (14th magnitude) to be spotted with anything less than a medium to large sized telescope – at least ones with primary mirrors of 8 to 16 inches. On the other hand it should be a fairly easy target for backyard digital astroimagers with the right setup even in light polluted suburbia. But because this supernova was caught early on, it may still have a surprise in store and continue to brighten a bit in the next week or so. No guarantees but the only way to know for sure is for us to keep an eye on it. i know where I will be pointing my telescope the next clear night!
Andrew Fazekas, aka The Night Sky Guy, is a science writer, broadcaster, and lecturer who loves to share his passion for the wonders of the universe through all media. He is a regular contributor to National Geographic News and is the national cosmic correspondent for Canada’s Weather Network TV channel, space columnist for CBC Radio network, and a consultant for the Canadian Space Agency. As a member of the Royal Astronomical Society of Canada, Andrew has been observing the heavens from Montreal for over a quarter century and has never met a clear night sky he didn’t like.