What is star Icarus?  What is gravitational lensing? « Back to Questions List

Icarus is the most distant star ever viewed by scientists.  The recently identified star is estimated to be located at a distance of 9.3 billion light years away from Earth. The star is named after ancient Greek mythological character Icarus.  Scientists say that it is twice as hot as sun and a million times brighter than sun. This type of star is called a blue super giant.  Stars that are among the most massive and most luminous stars are called super giants. Blue super giant is a rare type of star that is much bigger and more luminous than sun. 

Icarus in the Greek mythology is the character who flew close to the sun with wings made from wax. As he flew near to the sun, his feathers melted and fell gravely into the sea.  The star that is situated more than half way across the universe was formally named  MACS J1149+2223 Lensed Star-1.  But the scientists later on named it Icarus.  

The discoverers depended on Hubble Space Telescope of NASA to locate the star. The star is identified from the pinprick of light in an image captured by the telescope.  The team led by  Dr Patrick Kelly of the University of Minnesota and Judd Bowman of Arizona State University  made this great feat.  The research paper is published  in the journal Nature Astronomy. 

The newly discovered star is minimum 100 times further away than any other previously identified star. It is located in a distant spiral galaxy. Scientists had succeeded in identifying huge supernova explosions that leads to the death of certain stars and also older galaxies. But, their individual stars still remain unidentified. 

The phenomenon called   ‘gravitational lensing’ helped the scientists in identifying the star. In this phenomenon, bending of light by huge galaxy clusters in the line of sight amplifies more distant cosmic objects. Gravitational lensing thus makes faint, distant objects that otherwise would be invisible, visible. The segment of the universe where stars can be seen is very small. But, accidental events like gravitational lensing make scientists observe larger area.

According to researchers, discovery of Icarus aids them learn the earliest stages of universe, evolution of stars and first generation of stars.  The Bing Bang is estimated to have occurred 13.8 billion years ago.  The identified light from Icarus is expected to have originated when the universe was less than one third of its current age. 
 

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