A galactic fossil

Recent cosmological studies show that the Big Bang occurred 13.7 billion years ago. The metal-poor star HE 1523 formed in our Milky Way galaxy soon afterward, cosmologically speaking : 13.2 billion years ago. The primitive star contained the radioactive heavy elements uranium and thorium, and the amounts of those elements decay over time, each according to its own half-life. Today, astronomer Anna Frebel of the University of Texas at Austin McDonald Observatory and her colleagues have deduced the star's age based on the amounts of radioactive elements it contains compared to certain other "anchor" elements, specifically europium, osmium, and iridium. The study of the star's chemical make-up was made using the UVES spectrograph on the Kueyen Telescope, part of ESO's Very Large Telescope, at Paranal, in Chile.

Crédit:

ESO

À propos de l'image

Identification:eso0723a
Type:Collage
Date de publication:10 mai 2007
Communiqués de presse en rapport:eso0723
Taille:4961 x 2772 px

À propos de l'objet

Nom:HE 1523-0901
Type:Unspecified : Technology : Observatory : Telescope
Milky Way : Star
Catégorie:Illustrations
Stars

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