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A white dwarf is very hot when it forms, but because it has no source of energy, it will gradually cool as it radiates its energy away. This means that its radiation, which initially has a high color temperature, will lessen and redden with time. Over a very long time, a white dwarf will cool and its material will begin to crystallize, starting ...
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 Hertzsprung–Russell diagram showing the location of main sequence dwarf stars and white dwarfs. A dwarf star is a star of relatively small size and low luminosity. Most main sequence stars are dwarf stars. The meaning of the word "dwarf" was later extended to some star-sized objects that are not stars, and compact stellar remnants that ...
Van Maanen 2, or van Maanen's Star, is the closest known solitary white dwarf to the Solar System. It is a dense, compact stellar remnant no longer generating energy and has equivalent to about 68% of the Sun's mass but only 1% of its radius. [9] At a distance of 14.1 light-years it is the third closest of its type of star after Sirius B and ...
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 ...
After the helium too runs out, they begin to fuse carbon. When that also runs out, they shed their outer layers, creating a planetary nebula, and leaving behind, at the center of the nebula, a hot white dwarf. These stars remain stable for ~2-4 billion years. In comparison, G-type stars, like the Sun, stay stable for ~10 billion years. [13]
Compact object. In astronomy, the term compact object (or compact star) refers collectively to white dwarfs, neutron stars, and black holes. It could also include exotic stars if such hypothetical, dense bodies are confirmed to exist. All compact objects have a high mass relative to their radius, giving them a very high density, compared to ...
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 [5] [6] First singular white dwarf with a planet WD 1145+017: 2015 WD 1145+017 b: Planet is extremely small and is disintegrating. First white dwarf that is a pulsar: AR Scorpii A ...