UDFy-38135539

UDFy-38135539 (also known as HUDF.YD3) is a galaxy in the Fornax constellation. At present it is the farthest confirmed object ever seen. UDFy-38135539 is 13.1 billion light years from the Earth.

 Characteristics 
The galaxy is in the constellation Fornax, and it is estimated that the galaxy contains a billion stars.

 Significance 
The universe's first stars were massive, 
ionizing hydrogen in the surrounding environment.J Amos - 20 October 2010 - BBC News Retrieved 2012-6-18MIT Haystack observatory - index Retrieved 2012-06-18 This is called the ionization epoch.

UDFy-38135539 (HUDF.YD3) is probably the first galaxy seen in the reionization epoch. Caltech astronomer Brant Robertson, commenting on the study, stated that the "galaxy happens to reside at a very special time in cosmic history when the properties of gas in the universe were changing rapidly, and therefore this galaxy and others like it may teach us a lot about the early history of the universe". Michele Trenti, an astronomer who was not involved in the study but provided commentary published with the report, says that the discovery of the distant galaxy is  
"a fundamental leap forward in observational cosmology".

References

Category:Galaxies