An orbit that is an open curve whose ends get wider apart at any rate between that of an ellipse and a straight line. Some comets' orbits become hyperbolic through the gravitational influence of a pla
net the comet passes near.
A high luminosity star with absolute visual magnitude around -10, about 10^6 times as luminous as the Sun. Hypergiant stars are evolved massive stars belonging to the luminosity class Ia+ or Ia0. Thei
r spectra show very broadened emission and absorption lines resulting from the high luminosity and low surface gravity which favor strong stellar wind.