Research efforts to directly and indirectly detect Galactic dark matter complement each other, Oppenheimer and Alcock both say. That is the mass most known dwarfs have. Knowing where the dwarf stars are in the line of sight can help confirm this model. Oppenheimer intends to further characterize the stars, particularly the atmospheres and temperatures, which can help us understand star formation in the galaxy and the age of the halo. White dwarfs have atmospheres comprised of mostly hydrogen or helium and because they stop producing energy through nuclear fusion as they age, their temperatures drop.
Some white dwarfs are so cool they actually turn blue, giving off a unique luminosity.
Nigel Hambly of the University of Edinburgh in the United Kingdom identified 92 potential white dwarfs in recently digitized pictures of the southern sky, taken over a span of 30 years as part of the Royal Observatory Edinburgh's plate scanning project. These objects seemed to move at speeds fast enough to be an object in the halo. The scientists hope to repeat the project in the Northern Hemisphere of the Galaxy and collect a greater variety of data.