Search results
Results from the WOW.Com Content Network
The degenerate electrons in the bulk of a white dwarf conduct heat well. Most of a white dwarf's mass is therefore at almost the same temperature , and it is also hot: a white dwarf with surface temperature between 8000 K and 16 000 K will have a core temperature between approximately 5 000 000 K and 20 000 000 K. The white dwarf is kept from ...
White dwarfs arise from the cores of main-sequence stars and are therefore very hot when they are formed. As they cool they will redden and dim until they eventually become dark black dwarfs. White dwarfs were observed in the 19th century, but the extremely high densities and pressures they contain were not explained until the 1920s.
First white dwarf with a planet WD B1620−26: 2003 PSR B1620-26 b (planet) This planet is a circumbinary planet, which circles both stars in the PSR B1620-26 system [6] [7] First singular white dwarf with a transiting object WD 1145+017: 2015 Known object is a disintegrating planetesimal, most likely an asteroid. [8] First white dwarf that is ...
A PG 1159 star, often also called a pre-degenerate, [1] is a star with a hydrogen-deficient atmosphere that is in transition between being the central star of a planetary nebula and being a hot white dwarf. These stars are hot, with surface temperatures between 75,000 K and 200,000 K, [2] and are characterized by atmospheres with little ...
The white dwarf cooling anomaly is an additional cooling delay that has been observed for ultramassive forms of these compact stellar remnants. [ 1 ] [ 2 ] As a white dwarf cools, crystallization of the interior releases energy, slowing the cooling rate.
Single subdwarfs may be the result of a merger of two white dwarfs or gravitational influence from substellar companions. B-type subdwarfs, being more luminous than white dwarfs, are a significant component in the hot star population of old stellar systems, such as globular clusters and elliptical galaxies. [15] [16]
Stars tend to fall only into certain regions of the diagram. The most prominent is the diagonal, going from the upper-left (hot and bright) to the lower-right (cooler and less bright), called the main sequence. In the lower-left is where white dwarfs are found, and above the main sequence are the subgiants, giants and supergiants.
The white dwarf existed for 10.21 ±0.22 Gyrs, meaning the total age is 10.7 ±0.3 Gyrs. [1] Cold white dwarfs are often strongly affected by collision induced absorption (CIA) of hydrogen. This can lead to faint optical red and infrared brightness. These white dwarfs are also called IR-faint white dwarfs. WD J2147–4035 is however very red (r ...