White Dwarfs – A Light for Survival in a Dying Universe

A white dwarf is the stellar core remnant of a dwarf or main-sequence star composed mostly of electron degenerate matter. A white dwarf, like all final stages of a star’s life cycle , is immensely dense, since it contains the mass of a main-sequence star, similar to our sun, in a volume the  size of the Earth.

A white dwarf is formed when a main-sequence star has inadequate mass to become a neutron star and hence is unable to generate the core temperature required to fuse helium carbon after its helium-fusing period. This process takes place when due to the aforementioned issue, a mass of inert carbon and oxygen builds up at its centre. After this, the star sheds its outer layers in an exquisite planetary nebula. Planetary nebulae such as ESO 225-9 (The Ant Nebula) and NGC 6543 (the Cat’s Eye Nebula) are some of the nebulae you may have seen.

A planetary nebula is a relatively short-lived phenomenon, lasting for perhaps a few tens of thousands of years.  After a planetary nebula fades away, the star leaves behind a white dwarf about the size of the Earth.

A white dwarf does not undergo fusion reactions and consequently  cannot support itself from gravitational collapse with the heat generated by fusion. The only thing preventing it from gravitational collapse is electron degeneracy pressure, making it extremely dense.

When formed, a white dwarf is very hot, but, having no source of energy, it eventually cools as it radiates its energy away. Eventually, over tens, or even hundreds, of billions of years, white dwarfs will turn into black dwarfs.

Now, it’s about time we moved on to the topic of the title, how white dwarfs may be a source of heat and light for the survival of life in a dying universe. A dying universe, here, refers to a time period of the universe where all, or most, stars have either died or turned into white dwarfs. Life can exist around a white dwarf very similar to the way it can around a red dwarf.

But, all the perks of a planet around a white dwarf also come with the detriments. However, those problems may not apply as when a main-sequence star swells to the size of red giant, it consumes the planets close to it. Consequently, a civilisation of ships or satellites around the dwarf may be formed. The main advantage that white dwarfs have over red dwarfs is the lack of solar flares, making it much safer to reside near a white dwarf.

Well, that’ll  be it for this post of mine. I’ll probably be mixing it up with my next blog with a topic other than astrophysics.

Thank you for reading! Follow for more science content.

As usual I implore you to explore this and other related topics. Here’s a video about white dwarfs by the YouTube channel Kurzgesagt – In A Nutshell: