AQUILA  , in

astronomy, the " Eagle," sometimes named the " Vulture," a constellation of the northern hemisphere, mentioned by Eudoxus (4th cent . B.C.) and Aratus (3rd cent . B.C.) . Ptolemy catalogued nineteen stars jointly in this constellation and in the constellation Antinous, which was named in the reign of the emperor Hadrian (A.D . 117-138), but sometimes, and wrongly, attributed to Tycho Brahe, who catalogued twelve stars in Aquila and seven in Antinous; Hevelius determined twenty-three stars in the first, and nineteen in the second . The most brilliant star of this constellation, a-Aquilae or Altair, has a parallax of o.23", and consequently is about eight times as bright as the sun; n-Aquilae is a short-period variable, while Nova Aquilae is a " temporary " or " new star, discovered by Mrs Fleming of Harvard in 1899 .