- The gamma-ray emissions detected during the Dec. 25, 2010 event may not have been the result of an exploding star.
- An alternative theory is that a comet strayed too close to a neutron star.
- The neutron star's powerful tidal forces ripped the comet to shreds, generating prolonged gamma-ray emissions.
An artist's impression of a cometary body getting shredded by a neutron star. Click to enlarge this image.
A. Simonnet, NASA, E/PO, Sonoma State University
A burst of gamma-ray radiation from a distant galaxy, detected by an orbiting US telescope last Dec. 25, may have come from a comet crashing into a neutron star, astrophysicists suggest on Wednesday.
Gamma-ray bursts, or GRBs, are high-energy releases that often come from stars in their death throes.
The so-called Christmas Day GRB, spotted by NASA's Swift space telescope, has excited huge debate.
ANALYSIS: To GRB? Or Not to GRB? That is the WR 104 Question
Its gamma emissions lasted for at least half an hour, whereas the typical GRB lasts from just a couple of second to a few minutes, and its emissions in the X-ray part of the energy spectrum faded much faster than usual.
Poring over the data, a team led by Sergio Campana of the Brera Astronomical Observatory in Italy believe that the strange event was caused by a minor body such as a comet or asteroid that flew so close to a neutron star that it was ripped apart by intense tidal forces.
SLIDE SHOW: The Supercomputer Supernova
Its crashing fragments produced a prolonged series of mini gamma-bursts.
Another explanation, offered by Christina Thoene of the Institute of Astrophysics in Andalucia, southern Spain, is that the big GRB was the merger of a helium star and a neutron star, which created a supernova.
The two papers are published in the British science journal Nature.
Tags: Astrophysics, Christmas, Comets, Neutron Stars, Space Telescopes
comments ( )