The so-called hypervelocity object, which is either a low-mass star or a brown dwarf, is traveling through the Milky Way at around a million miles an hour. The so-called hypervelocity object, which is either a low-mass star or a brown dwarf, is traveling through the Milky Way at around a million miles an hour. Stars and Galaxies, Milky Way Galaxy, Space and Astronomy, Research, Astrophysical Journal Letters NYT > Science