Long-period comet, discovered individually by amateur astronomers Alan Hale and Thomas Joel Bopp, the 23rd of July, 1995. Designated C/1995 O1, in that date it was still more than 7 AU away from the Sun. Typical features were a series of jets and dust layers ejected by the nucleus, as it rotated with an 11.5 hour period. The comet reached perigee (at 1.32 AU) on the 22nd of May, 1997, and perihelion (at 0.91 AU) on the 1st of April, 1997. Its brightest magnitude was -5. Its orbit has a 2,400 year period.