Title: The Binary Fraction of Stars in Dwarf Galaxies: the Cases of Draco and Ursa MinorAuthors: Meghin Spencer, Mario Mateo, Edward Olszewski, Matthew Walker, Alan McConnachie, Evan KirbyFirst Author’s Institution: University of Michigan, Ann Arbor, MIStatus: Published in AJ; open access on arXivDisclaimer: My advisor is an author on this paper, but somehow I didn’t realize that until after I’d finished writing the entire post. Hopefully you’ll forgive my compromised journalistic integrity!
Stars aren’t usually only children. In fact, we think most stars are born in binary or multiple systems. But just how many binary systems are out there?
Understanding the fraction of binary stars is important in studying galaxies. For example, the number of binaries can affect some estimates of global galaxy parameters like star formation rates, which depend heavily on models of stellar populations. Binary stars can also lead to events like Type Ia supernovae (the thermonuclear explosions of some white dwarf stars with binary companions), so knowing the fraction of binary stars can help us figure out the rates of these events.
Binary stars might be even more important in the smallest and faintest of galaxies, called “ultra-faint dwarf galaxies” (UFDs). UFDs are strange systems. They ...