white dwarf tagged posts

Scientists discover one of the most Luminous ‘New Stars’ ever

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

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...

Read More

Surface Helium Detonation Spells End for White Dwarf

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

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 ...

Read More

Very Rare Discovery: Failed Star Orbits a Dead Star every 71 minutes

K2 lightcurve (black jagged curve) folded about a period of 71.23 minutes. The red curve represents a simple geometrical model with a 5-minute long total eclipse and a 9% contribution to emulate an illumination effect on the companion star. The blue curve is the fit to the model based on the length of the K2 observations. Credit: Bishop's University

1. K2 lightcurve (black jagged curve) folded about a period of 71.23 minutes. The red curve represents a simple geometrical model with a 5-minute long total eclipse and a 9% contribution to emulate an illumination effect on the companion star. The blue curve is the fit to the model based on the length of the K2 observations. 2. The final fate of WD1202 as a cataclysmic variable. The brown dwarf overflows its tear-drop-shaped Roche lobe and loses mass to the compact white dwarf accretor An accretion disk of hot hydrogen gas surrounds the white dwarf. Credit: Bishop’s University

An international team using data from the rejuvenated Kepler space telescope have discovered a rare gem: A binary system consisting of a failed star, also known as a brown dwarf, and the remnant of a dead star known ...

Read More

Calculations Show Close Ia Supernova should be Neutrino detectable offering possibility of identifying Explosion type

Density contour plots including deflagration (white) and detonation (green) surfaces. Credit: arXiv:1609.07403 [astro-ph.HE]  Read more at: https://phys.org/news/2017-03-ia-supernova-neutrino-possibility-explosion.html#jCp

Density contour plots including deflagration (white) and detonation (green) surfaces. Credit: arXiv:1609.07403 [astro-ph.HE]

A team of researchers at North Carolina State University has found that current and future neutrino detectors placed around the world should be capable of detecting neutrinos emitted from a relatively close supernova. They also suggest that measuring such neutrinos would allow them to explain what goes on inside of a star during such an explosion—if the measurements match one of two models the team built to describe the inner workings of a supernova.

Supernovae have been classified into different types depending on what causes them to occur—one type, a la supernova, occurs when a white dwarf pulls in enough material from a companion, eventually triggering carbon fus...

Read More