Ikeya-Seki comet(ee-kay -ă sek -ee) (1965 VIII) A comet that was discovered by two amateur Japanese comet searchers. At one time it was actually thought that it would hit the Sun but it turned out to be a sungrazing comet with a perihelion distance of 0.0078 AU, missing the Sun's surface by 0.68 solar radii. The orbit is retrograde with an eccentricity of 0.99915.
a comet discovered independently by the Japanese observers Kaoru Ikeya and Tsutomu Seki on Sept. 18, 1965, as a diffuse object of the eighth stellar magnitude; it was traveling in an almost parabolic orbit. It belongs, like the Great Comet 1882, to the family of sun-grazing comets, which are characterized by an exceedingly small perihelion distance q and, evidently, occur as a result of the breakup of a single comet. On Oct. 21, 1965, the Ikeya-Seki comet passed through the solar corona at a distance of about 500,000 km from the sun (q = 0.008 astronomical units); it was observed by day in the immediate vicinity of the sun. After its perihelion passage it was observed as an exceedingly bright object in the predawn sky and had a tail extending for tens of degrees. Spectra of the comet, obtained during its passage near the sun, are rich in multiple emissions due to metals and are reminiscent of meteor spectra. The Ikeya-Seki comet has provided abundant material for the development of comet and meteor astronomy.