Zooming into the centre of the galaxy M82 reveals an expanding shell, the blast wave from a supernova.
Spotted—the nearest supernova seen in the last five years
4 Jun 2009
The chance discovery in April of a rare "radio supernova"—an exploding star detectable only at radio wavelengths and unseen by optical or X-ray observatories—heralds the promise of new ways to find supernovae hidden inside interstellar gas and dust clouds.
The supernova was the nearest seen in the last five years, yet our view of it was completely blocked at optical, ultraviolet and X-ray wavelengths due to the dense dust in its galaxy. It was spotted in M82, a small galaxy nearly 12 million light years from Earth in the M81 galaxy group
It was detected on April 8 by the Very Large Array (VLA), a collection of radio dishes in New Mexico operated by the US National Radio Astronomy Observatory (NRAO). It was subsequently confirmed by NRAO's Very Long Baseline Array (VLBA), a 10-telescope array which stretches from Hawaii to the Virgin Islands, providing the sharpest vision of any telescope on Earth.
Radio emissions from supernovae can help astronomers understand how stars explode and what happens before their cores collapse to form a neutron star or black hole. The radio emissions are caused when the blast wave from the explosion collides with gas previously shed by the stars.
< Part of the Allen Telescope Array.
The Allen Telescope Array ATA, currently comprising 42 of a planned 350 radio dishes, has begun a survey of the sky that should turn up many more such radio supernovae.
While the VLA and VLBA have very narrow fields of view unsuited to all-sky surveys, the ATA's wide-angle view is ideal for scanning the whole sky once per day, which is necessary to find sources that brighten and dim over several days.
Not all supernovae produce radio emissions. If the star didn't blow off much of its gas before collapsing inward to form a neutron star or black hole, then few radio emissions are produced from the blast hitting the gas.
On the other hand, blasts from supernovae in very active star-forming regions, like the centre of M82, should produce copious radio emissions because of the density of gas and dust in the space there.
Adapted from information issued by UC Berkeley / Milde Science Communication / NASA / ESA / HHT (STScI/AURA) / A. Brunthaler, MPIfR.
LATEST HEADLINES & TOP STORIES:
> How to find water worlds in space
> Shuttle launch pad prepares for new Moon rocket
> Spotted—the nearest supernova seen in five years
> DOWN TO EARTH: Indonesia's dragon island, seen from space
> Become a Red Planet explorer!
> 50,000 computers are looking for pulsars
> NASA tests largest-ever rocket parachutes
> DOWN TO EARTH: A water-filled Lake Eyre, seen from space
> SETI@home project turns 10
> Woomera hyper-flight test a success
> Student names NASA's new Mars rover
> NASA launches tiny satellite
> Up close with a black hole
> Is gravity wrong?
> Landmark experiment's 90th anniversary
> NASA astronaut to give Sydney lecture
> Earth's blasted life has a long history
> Space Station news conference on Monday—watch it live
> OasISS mission led by European astronaut
> Canadian to spend six months on Space Station
> NASA rover reveals Mars' hidden history
> DOWN TO EARTH: Mexico's super-volcano seen from space
> Recycling reaches the space station
> MAIN NEWS PAGE…
Search SpaceInfo…
