| Brown dwarf (16) |  |
| Red dwarf (6) | |
| White dwarf (23) | |
| Brown dwarf (16) | |
| Red dwarf (6) | |
| White dwarf (23) | |
#Star collision may explain the lonely supernova University of Warwick rightoriginal Studyposted by Tom Frew-Warwick on August 11 2014 A massive collision between white dwarf
instead between a white dwarf star and neutron star it would fit their observations because: hat we therefore propose is these are systems that have been ejected from their galaxy.
A good candidate in this scenario is a white dwarf and a neutron star in a binary system. The neutron star is formed
and if the binary system survives the kick the white dwarf and neutron star will merge causing the explosive transient. he researchers who say such merging systems of white dwarfs
and neutron stars may produce high energy gamma-ray bursts will next look for any new examples of calcium-rich transients to confirm this.
our solar system orbiting a white dwarf star 170 light years away. Using observations obtained with the Hubble Space Telescopeâ
In the study published in Science researchers suggest it is most likely that the water detected around the white dwarf GD 61 came from a minor planet at least 90 kilometers (56 miles) in diameterâ
##but potentially much biggerâ##that once orbited the parent star before it became a white dwarf.
From the amount of rocks and water detected in the outer envelope of the white dwarf the researchers estimate that the disrupted planetary body had a diameter of at least 90 kilometers.
and became a white dwarf yet parts of its planetary system survived. The water-rich minor planet was knocked out of its regular orbit
Researchers believe that destabilizing the orbit of the minor planet requires a so far unseen much larger planet going around the white dwarf. t this stage in its existence all that remains of this rocky body is simply dust
. or their analysis the researchers used ultraviolet spectroscopy data obtained with the Cosmic Origins Spectrograph on board the Hubble space telescope of the white dwarf GD 61.
The Hubble and Keck data allows the researchers to identify the different chemical elements that are polluting the outer layers white dwarf.
Using a sophisticated computer model of the white dwarf atmosphere developed by Detlev Koester at the University of Kiel they were able to infer the chemical composition of the shredded minor planet.
which a white dwarf star somehow reaches a critical mass of about 1. 4 solar masses and explodes.
They found the classic signature of a thermonuclear explosion of a white dwarf. The process begins with the compression of the white dwarf leading to the formation of nickel-56
which decays to cobalt-56 which in turn decays to a stable isotope of iron producing characteristic gamma rays.
In the favoured model called the single degenerate system a white dwarf reaches its critical mass by stealing material from an ordinary companion star.
In an alternative double degenerate model two white dwarfs orbiting each other cause the explosion either by merging or by one poaching matter from the other.
In a single degenerate system the shock wave from the white dwarf explosion should smash into the surrounding gas from the companion star generating radio waves.
so concluded SN 2014j probably began as two white dwarfs. Robert Kirshner of Harvard university who studies type IA supernovae is convinced not yet.
Sometimes when a white dwarf star dies it explodes as a type 1a supernova. All supernovae in this class reach a very specific colour and peak brightness creating
and thought to be caused by the collision of two neutron stars black holes or white dwarfs. The pair suggest that the odd isotope levels in the trees
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