Milky Way Our solar system is in an outer spiral arm of the Milky Way, but do we know where our galaxy is within the universe?
Deep-Sky Objects Messier’s 102nd entry is known as the lost Messier object. Has there been any agreement on what this M object might be?
Stars Sirius, our brightest star, is orbited by a white dwarf — a dead star’s core. Where is the planetary nebula that would have formed when it shed its skin?
Exoplanets, Planets At tens, hundreds, or thousands of light-years from a star, how do you distinguish between exoplanets, sunspots, and dwarf binary companions?
