Ars
Technica: A
type
Ia supernova occurs when a white dwarf star being orbited
by a secondary star pulls enough material from the secondary
star to cause a thermonuclear explosion. So bright are the
supernovae that their light vies with that of the system's
parent galaxy. While the
Hubble Space Telescope was being used for the Cosmic
Assembly Near-Infrared Deep Extragalactic Legacy Survey
(CANDELS), it detected a sudden increase in the brightness of
one of the galaxies in its field of view. An analysis of the
light indicated that it was a type Ia supernova. At 10 billion
light-years away, the supernova was 350 million light-years
farther than the previous distance record holder. That made it
only the eighth type Ia supernova found farther than 9 billion
light-years away. Because white dwarfs are the end stages of
some stars' life cycles, the earliest type Ia supernovae had to
wait until the first generation of white dwarf precursors had
lived and died.
