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Hubble looking into the past.

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.[1][2]

Characteristics[change | change source]

The galaxy is in the constellation Fornax, and it is estimated that the galaxy contains a billion stars.[3]

Significance[change | change source]

The universe's first stars were massive, ionizing hydrogen in the surrounding environment.[3][4][5][6] This is called the ionization epoch.

UDFy-38135539 (HUDF.YD3) is probably the first galaxy seen in the reionization epoch.[7] 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".[8] 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".[8]

References[change | change source]

  1. "BBC News - Galaxy is most distant object yet". bbc.co.uk. 2011. Retrieved March 1, 2011.
  2. "Hubble finds a new contender for galaxy distance record". Space Telescope (heic1103 - Science Release). 26 January 2011. Retrieved 2011-01-27.
  3. 3.0 3.1 Trenti, Michele (2010). "Astronomy: Galaxy sets distance mark". Nature. 467 (7318): 924–925. doi:10.1038/467924a. PMID 20962835. S2CID 43005537.
  4. "Oldest object in Universe found". Discovery News. Retrieved 2010-10-21.[permanent dead link]
  5. J Amos - 20 October 2010 - BBC News Retrieved 2012-6-18
  6. MIT Haystack observatory - index Retrieved 2012-06-18
  7. "Dim galaxy is most distant object yet found". New Scientist. Retrieved 2010-10-21.
  8. 8.0 8.1 "Earliest galaxy helped clear Big Bang's fog". USAToday. 2010-10-20.