Sirius B, which is a white dwarf, can be seen as a faint point of light to the lower left of the much brighter Sirius A. A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: in an Earth sized volume, it …

白矮星（white dwarf，也称为简并矮星）是一种低光度、高密度、高温度的恒星。 白矮星是由简并电子的压力抗衡引力而维持平衡状态的致密星。 因早期发现的大多呈白色而得名。

白矮星，也稱為 簡併矮星，是一種主要由 電子簡併物質 構成的 恆星核殘骸。 白矮星具有非常高的 密度：它的質量與 太陽 相當，體積與 地球 相近。 白矮星沒有 核融合 來產生能量，微弱的 亮度 來自儲存的 能量 的 熱輻射 [1]。 已知距離最近的白矮星是 天狼星 B，是在8.6光年的 聯星，天狼星A的伴星。 目前，在距離太陽最近的百顆恆星系統中，有8顆白矮星 [2]。 異常昏暗的白矮星在1910年首次被確定 [3]:1； 白矮星 名稱是由 威廉·魯伊登 在1922年命名的 [4]。 白矮星被認為 …

A low or medium mass star (with mass less than about 8 times the mass of our Sun) will become a white dwarf. A typical white dwarf is about as massive as the Sun, yet only slightly bigger than the Earth. This makes white dwarfs one of the densest forms of matter, surpassed only by neutron stars and black holes.

2021年9月23日 · A white dwarf is what stars like the Sun become after they have exhausted their nuclear fuel. Near the end of its nuclear burning stage, this type of star expels most of its outer material, creating a planetary nebula.

MWDD is a user friendly tool to explore and display data from spectroscopically confirmed white dwarfs published in the literature. Basic white dwarf properties from evolutionary models and diffusion timescales for heavy elements are also accessible. MWDD currently includes data compiled from papers and a few websites (see references).

White dwarf stars are extreme objects that are roughly the same size as the Earth. They have densities typically around 10 9 kg/m 3 (the Earth has a density of around 5×10 3 kg/m 3) meaning that a teaspoon of white dwarf material would weigh several tonnes. The easiest way to picture this is to imagine squeezing the mass of the Sun into an ...

White dwarfs are thought to be the final evolutionary state of all stars whose mass is not too high—over 97 percent of the stars in our Galaxy. After the hydrogen - fusing lifetime of a main-sequence star of low or medium mass ends, it will expand to a red giant, which fuses helium to carbon and oxygen in its core by the triple-alpha process.

A white dwarf is the stellar core left behind after a dying star has exhausted its nuclear fuel and expelled its outer layers to form a planetary nebula. The ultimate fate of a star depends on its initial mass.

When they reach the end of their long evolutions, smaller stars —those up to eight times as massive as our own sun—typically become white dwarfs. These ancient stars are incredibly dense. A...