UDFj 39546284

UDFj-39546284 is the designation given to a stellar structure reported on January 27, 2011, as light from the oldest object detected through infrared observation within the Hubble Space Telescope. The object, located in the Fornax constellation, was identified by G. Illingworth (University of California), R. Bouwens (University of California and Leiden University) and the HUDF09 Team during 2009 and 2010. It was initially thought (November 2012) to be at redshift z~10 using Hubble and Spitzer telescope photometric data, including Hubble Extreme Deep Field (XDF). Subsequently it was reported (December 2012) to possibly be at a record-breaking redshift z = 11.9 using Hubble and Spitzer telescope data, including Hubble Ultra-Deep Field (HUDF). Recent analyses (March 2013) have suggested this source is more likely to be a low redshift interloper, with extreme emission lines in its spectrum producing the appearance of a very high redshift source.