What is a black dwarf star? Does it have proven existence or is it hypothetical?

1 Answer
Dec 7, 2015

Black dwarfs are completely hypothetical.

Explanation:

A black dwarf is considered to be the final stage of a normal sized star like our Sun. Our Sun is 4.5 Billion years old and it has enough hydrogen to burn for the next 4.5 Billion years. After 10 Billion years the Sun would have burned all pf its hydrogen to Helium, its core will shrink and outer layers will expand. This stage is called Red Giant stage.

In the Red giant stage the Sun will further burn Helium for the next 100 million years to carbon. After the Sun has consumed all of its Helium it would not be dense enough to burn Carbon. At this point the fusion reactions will stop and the core will collapse. The Red Giant star will calmly shed its outer layers into space forming a White dwarf.

It is hypothesized that this White dwarf stage will continue for the next 100 Billion years until it can no longer radiate energy and heat thus forming a Black dwarf. These so called Black dwarf stars are completely hypothetical as the universe is not old enough for any white dwarf to turn into a black dwarf.