Supernova star too close for comfort
Image:
Astronomers have identified a ticking time-bomb in space that lies perilously close to the Earth, they revealed today. The star, called T Pyxidis, looks set to explode as a supernova with the force of 20 billion billion billion megatons of TNT.
But it lies less than 3,260 light-years away in our own galaxy - close enough in cosmic terms for a blast to have a possibly devastating impact on our planet.
In their news release, the scientists say that a thermonuclear explosion at such a close distance will "fry the Earth", dumping as much gamma ray energy as 1,000 solar flares at once. It will strip away the ozone layer, allowing deadly radiation to bombard all life.
The star, in the southern constellation of Pyxis, the compass, has erupted before in cosmic burps as a normal, less powerful nova. Explosions were seen at approximately 20-year intervals in 1890, 1902, 1920, 1944 and 1967. But it is 44 years overdue for its next blast and astronomers do not know why.
New studies using the International Ultraviolet Explorer satellite show that it is much closer to us than previously thought and is a double-star system with one star like the sun and a smaller denser star called a white dwarf.
The white dwarf is steadily becoming more massive as gas flows onto it from its companion. The scene looks set for it to reach a critical stage - called the Chandrasekhar Limit - where it suddenly collapses under its own weight triggering an unimaginably powerful thermonuclear explosion that destroys it completely. The star will then become as bright as all other stars in the galaxy put together and shine like a beacon halfway across the universe.
This catastrophic event, called a Type Ia supernova, will release ten million times more energy than a normal nova. The doomsday scenario was described today by astronomers Edward M. Sion, Patrick Godon and Timothy McClain from Villanova University, Philadelphia, at a conference of the American Astronomical Society in Washington.
They said that pictures taken by the Hubble space telescope of shells of material thrown off in previous eruptions fitted the view that star is set to go supernova.
It sounds scary stuff. And the astronomers' news release suggest it will happen "soon". But I contacted the lead researcher, Dr Ed Sion, and he told me: "At the accretion rate we derived, the white dwarf in T Pyxidis will reach the Chandrasekhar Limit in ten million years. I hope this alleviates any worry by readers."
So no need to lose any sleep!
Picture: A Hubble photo of T Pyxidis, showing the shell of debris thrown off by a nova blast. (NASA/ESA).
* Discover space for yourself and do fun science with a telescope. Here is Skymania's advice on how to choose a telescope. We also have a guide to the different types of telescope available.
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10 Comments
Add CommentWell, that's a relief. I was packing for a trip down a mine shaft halfway through reading this article.
Reply | Report Abuse | Link to thisHow can the Chandrasekhar limit ever be reached,if smaller novas keep blowing the material off every 20 years or so?
Reply | Report Abuse | Link to thisAlso, let's get through this global warming and peak oil and overpopulation thing first and then maybe our grandchildren can build some giant "shades" around the earth. ;-)
Reply | Report Abuse | Link to thisjack...that's what i was thinking too....its the definition of a nova...what are they saying?, that the white dwarf will become a neutron star or a black hole...not...I think the article is stating that they're worried about a 44 year miss in a nova event...please someone clarify....thanks.
Reply | Report Abuse | Link to thisa think your very crrect in what your saying just look at the weather in uk,global warming my ass the pole's have been waxing and waning for millenia and we should start acting like human and care for our children's planet thanks ,john gibson...
Reply | Report Abuse | Link to thisdon't think more and more. just do your good work. The death time is fix for every one. so do best in your life and enjoy the life.
Reply | Report Abuse | Link to thisif we observe from earth something going on at 3000 lightyears away, than this event happened 3000 years ago. So Pyxidis might already be an empty place in space (or a black hole for that matter), strange isn't it ?
Reply | Report Abuse | Link to thisIs that what some are calling Planet X? That seems to be a well kept secret among most of the population. It appears to have a tail that periodically it whips out and lashes whatever is in it's way. Would like to know a little informtion on this is possible, thankyou very much. aries76@clearwire.net
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