Article Posted on : - Oct 03, 2011

Galaxy Arp 220 with some of its newly discovered supernovae (inset, taken with Global VLBI). Photo: NASA, ESA, Hubble Heritage Team, Chalmers.

WASHINGTON (BNS): Astronomers have discovered seven previously unknown supernovae in a galaxy which is 250 million light years away, according to a media report.

A team at Chalmers and Onsala Space Observatory in Sweden says that, never before have so many supernovae been discovered at the same time in the same galaxy.

The discovery proves what astronomers have long believed: that the galaxies which are the universe's most efficient star-factories are also supernova factories.

According to Science Daily, astronomers tried to create extremely sharp images of the galaxy Arp 220 by using a worldwide network of radio telescopes in five countries, including Sweden.

The scientists observed around 40 radio sources in the center of the galaxy Arp 220. These radio sources are hidden behind thick layers of dust and gas and invisible in ordinary telescopes.

To discover the nature of these radio sources, they made measurements at different radio wavelengths and watched how they changed over several years.

So many supernovae have never before been detected in the same galaxy. The number is nevertheless consistent with how fast stars are forming in Arp 220. The radio measurements have also given researchers insight into how radio waves are generated in supernovae and their remnants.

The observations were carried out using telescopes which belong to the European VLBI Network (EVN) together with the Very Long Baseline Array (VLBA).