If a red giant has less than ten times the mass of the Sun, it collapses into a white dwarf - a hot, white-coloured star about the size of the Earth. White dwarfs cool over billions of years, gradually changing colour as they do so from white to orange, to yellow, to red, to brown and, finally, black. It is estimated that there are about ten billion white or other dwarf stars in our own galaxy*, the Milky Way. The matter they are made of is so dense that a litre of it on Earth would weigh as much as the Titanic!
|
