10-04-2017, 06:11 PM
"Surface helium detonation spells end for white dwarf"
This is an interesting one which came from observations carried out by the Subaru Observatory on MK. In general, there are two types of supernovae (stars that end their lives by blowing themselves to pieces). Unlike a star with a mass similar to our sun, massive stars end their lives by running out of fuel. This means they can no longer hold up against their own force of gravity. They collapse which increases the pressure and temperature inside the star and you get runaway nuclear fusion and a huge explosion.
The other type is when the dense but small remnant of a star like our sun has a companion star. The dense white dwarf accretes material from its companion's surface layers until it has more mass than it can cope with and again, explodes. In this particular case, it seems that an outer layer of helium on the white dwarf exploded blowing the star to smithereens. Although it's not specified in the article, I suspect this means the helium was taken off a companion red giant star, one which our own sun will become one day. Such stars run out of hydrogen leaving behind mostly helium. I've no idea what happened to the red giant companion after the supernova though.
https://phys.org/news/2017-10-surface-he...dwarf.html
This is an interesting one which came from observations carried out by the Subaru Observatory on MK. In general, there are two types of supernovae (stars that end their lives by blowing themselves to pieces). Unlike a star with a mass similar to our sun, massive stars end their lives by running out of fuel. This means they can no longer hold up against their own force of gravity. They collapse which increases the pressure and temperature inside the star and you get runaway nuclear fusion and a huge explosion.
The other type is when the dense but small remnant of a star like our sun has a companion star. The dense white dwarf accretes material from its companion's surface layers until it has more mass than it can cope with and again, explodes. In this particular case, it seems that an outer layer of helium on the white dwarf exploded blowing the star to smithereens. Although it's not specified in the article, I suspect this means the helium was taken off a companion red giant star, one which our own sun will become one day. Such stars run out of hydrogen leaving behind mostly helium. I've no idea what happened to the red giant companion after the supernova though.
https://phys.org/news/2017-10-surface-he...dwarf.html