All Articles Tagged As: white dwarves

Asymmetric accretion disk causes X-ray flux variations in bright supersoft nova (4/13/2008)

When a white dwarf accretes matter from his larger companion star and after reaching a critical mass ejects it in an explosion a nova occurs. Soft X-rays from classical novae are especially interesting for astronomers: They reveal ongoing residual hydrogen burning after the explosion and so give evidence that some of the accreted material is left on the white dwarf surface after the ejection. In this way the long-term evolution of the white dwarf in a binary system can be studied, for example to answer the question if the nova will later transform into a type Ia supernova, the most luminous supernova type. ...> Full Article

Astronomers coordinating international observatories in white-dwarf watch (3/29/2008)

Judi Provencal is star-struck, but not so much by the glitz and glam of Hollywood. ...> Full Article

Unusual supernovae may reveal intermediate-mass black holes in globular clusters (1/30/2008)

A strange and violent fate awaits a white dwarf star that wanders too close to a moderately massive black hole. According to a new study, the black hole's gravitational pull on the white dwarf would cause tidal forces sufficient to disrupt the stellar remnant and reignite nuclear burning in it, giving rise to a supernova explosion with an unusual appearance. Observations of such supernovae could confirm the existence of intermediate-mass black holes, currently the subject of much debate among astronomers. ...> Full Article

Examining Violent Explosions Called Novae Has Produced Unified Model For Nearby Nova (1/30/2008)

First results from a new NASA-funded scientific instrument at the W. M. Keck Observatory in Hawaii are helping scientists overturn long-standing assumptions about powerful explosions called novae and have produced the first unified model for a nearby nova called RS Ophiuchi. ...> Full Article

White Dwarf Pulses Like A Pulsar (1/3/2008)

New observations from Suzaku, a joint Japanese Aerospace Exploration Agency (JAXA) and NASA X-ray observatory, have challenged scientists' conventional understanding of white dwarfs. Observers had believed white dwarfs were inert stellar corpses that slowly cool and fade away, but the new data tell a completely different story. ...> Full Article

Astronomers Discover Stars with Carbon Atmospheres (11/22/2007)

Astronomers have discovered white dwarf stars with pure carbon atmospheres. These stars possibly evolved in a sequence astronomers didn't know before. ...> Full Article