Would the presence of many white dwarfs in the halo impact current notions of star formation?
Let’s assume for the moment that there is a very large population of white dwarfs in the halo. As mentioned above, most stars end up as white dwarfs, but the lowest mass stars (so-called M and K dwarfs, or red dwarfs) take an extremely long time to evolve from their stellar states to the white dwarf stage. In fact, according to our current understanding of stellar evolution, these stars take so long to evolve into white dwarfs that even one born close to the beginning of time (some 10 to 13 billion years ago), would still have not reached the white dwarf stage. People have actually measured the numbers of these M and K dwarfs in the Galaxy’s halo. There are very few, and it is possible that there are many times as many white dwarfs in the halo as one would expect based on the numbers of M and K dwarfs in the halo. That statement assumes that the stars in the halo formed exactly the same way as stars are forming now in the Galaxy’s disk. In other words, we find that stars form at a rang
