white dwarf tagged posts

X-ray images give unprecedented view of extremely rare type of supernova. New information suggests that these supernovae start as compact stars that lose mass at the end of life. Calcium-rich supernovae are responsible for up to half the calcium in the entire universe. SN 2019ehk has the richest calcium emission of all known transients.

Called “calcium-rich supernovae,” these stellar explosions are so rare that astrophysicists h...

Hubble captures planetary nebula NGC 6326
Credit: ESA/Hubble & NASA

The Hubble Space Telescope captured what looks like a colorful holiday ornament in space. It’s actually an image of NGC 6326, a planetary nebula with glowing wisps of outpouring gas that are lit up by a central star nearing the end of its life.

When a star ages and the red giant phase of its life comes to an end, it starts to eject layers of gas from its surface leaving behind a hot and compact white dwarf. Sometimes this ejection results in elegantly symmetric patterns of glowing gas, but NGC 6326 is much less structured. It is in the constellation of Ara, the Altar, 11,000 light-years from Earth.

Planetary nebulae are one of the main ways in which elements heavier than hydrogen and helium are dispersed into space after th...

Left: the nova system before eruption. Right: the nova system in outburst.
Credit: OGLE survey

University of Leicester contributes to best-ever results on a ‘new star’ in a nearby galaxy. Astronomers have today announced that they have discovered possibly the most luminous ‘new star’ ever – a nova discovered in the direction of one of our closest neighboring galaxies: The Small Magellanic Cloud.

Astronomers used Swift satellite observatory to help understand what was likely the most luminous white dwarf eruption ever seen. A nova happens when an old star erupts dramatically back to life...

A hybrid type Ia supernova with an early flash triggered by helium-shell detonation. Nature, 2017; 550 (7674): 80 DOI: 10.1038/nature23908

Researchers have found evidence that the brightest stellar explosions in our Universe could be triggered by helium nuclear detonation near the surface of a white dwarf star. The most famous supernovae are the result of a massive star exploding, but a white dwarf, the remnant of an intermediate mass star like our Sun, can also explode. This can occur if the white dwarf is part of a binary star system. The white dwarf accretes material from the companion star, then at some point, it might explode as a type Ia supernova.

Because of the uniform and extremely high brightness (about 5 billion times brighter than the Sun) of type Ia supernovae, they are often ...