![]() ![]() “That is what was responsible for the brightening of by a factor of four.” But sometimes a star kind of floating in the middle of a cluster will also get in the right place and that will contribute additional magnification,” said Kelly. ![]() “Usually the stars by about 600 that is just due to the cluster itself. The increase in brightness of Icarus, the researchers say, is due to an additional magnification boost from a star within the galaxy cluster. The speck, the team determined, was down to a star whose brightness had been magnified by a phenomenon known as gravitational lensing whereby light emitted by the star is bent by the gravitational effect of objects in front of it – in this case the galaxy cluster. “As we monitored the cluster due to SN Refsdal, we obtained imaging of the cluster regularly, and we saw the ‘Icarus region’ brightening up,” said Dr Mathilde Jauzac, another author of the study from Durham University. This seemed to come from an object in the same galaxy as the supernova, and appeared in the environs of a well-known galaxy cluster that lay just over 5bn light years from Earth. The team were studying a supernova known as SN Refsdal in a galaxy more than 9bn light years away when they noticed a pinprick of light that appeared four times brighter than in previous images. Writing in the journal Nature Astronomy, an international team of researchers reveal how their curiosity was piqued in 2016. “It’s more than 100 times farther away than the next most distant individual star we can observe,” said Kelly. But it seems a chance alignment of the heavens made Icarus visible. Stars at such distance are normally too faint to be identified individually, unless they explode in a supernova. “We are looking back three-quarters of the way almost to the big bang,” said Dr Patrick Kelly, first author of the research from the University of Minnesota. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |