:''There are two comets named Ikeya-Seki: C/1965 S1 (this one), and
C/1967 Y1, a.k.a. 1968 I, 1967n.''
'Comet Ikeya-Seki',
formally designated 'C/1965 S1', '1965 VIII', and '1965f', was a
comet discovered independently by
Kaoru Ikeya and
Tsutomu Seki. First observed as a faint telescopic object on
September 18,
1965, the first calculations of its orbit suggested that on
October 21, it would pass just 450,000 km above the
Sun's surface, and would probably become extremely bright.
Comets can defy all predictions, but Ikeya-Seki performed as expected. As it approached
perihelion observers reported that it was clearly visible in the daytime sky next to the Sun. In
Japan, where it reached
perihelion at local noon, it was seen shining at
magnitude −10
[1]. It proved to be one of the brightest comets seen in the last thousand years, and is sometimes known as the ''
Great Comet of 1965''.
The comet was seen to break into three pieces just before its perihelion passage. The three pieces continued in almost identical orbits, and the comet re-appeared in the morning sky in late October, showing a very bright tail. By early
1966, it had faded from view as it receded into the outer
solar system.
Ikeya-Seki was a member of the
Kreutz Sungrazers, which are all fragments of a large comet which broke up in
1106. The two largest fragments of Ikeya-Seki, labeled S1-A and S1-B, will return to the inner Solar System in 877 and 1,056 years, respectively.(JPL)
Gallery
Reference
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JPL Orbit Diagrams