Astronomers using two telescopes atop Mauna Kea in Hawaii have discovered a pair of supernovae that occurred more than 10 billion years ago, when the universe was less than a quarter of its present age. The researchers were able to spot the ancient stellar explosions, whose light has only just reached Earth, because of the extreme luminosity of the supernovae—the newly discovered blasts may signal the cataclysmic death of giant stars more than 100 times as massive as the sun.

Jeff Cooke of the Swinburne University of Technology in Australia and his colleagues reported the discoveries in a study published online October 31 in Nature. The supernovae pair, which have been designated SN2213-1745 and SN1000+0216, were identified from deep-sky images taken at the 3.6-meter Canada—France-–Hawaii Telescope between 2003 and 2008. SN2213-1745 lies at a redshift of 2.05, which implies that the supernova’s progenitor star exploded 10.4 billion years ago. (The universe is now about 13.7 billion years old.)

The star that exploded as SN2213-1745 may have been as massive as 250 suns, the researchers estimate. SN1000+0216, which lies at a redshift of 3.9, went off some 12 billion years ago. The discovery smashes the record held by a supernova identified by Cooke and his colleagues in 2009 at redshift 2.36, which corresponds to a light-travel time of about 11 billion years. The data on the distant cataclysm are too limited to determine the exact mechanism behind the luminous blast.

foto: Simulation of an early galaxy hosting a superluminous supernova. Credit: Adrian Malec and Marie Martig (Swinburne University); sursă ştire: Astronomers Spot Most Distant Supernova Yet.

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