Comet Ikeya–Seki

Comet Ikeya Seki (C/1965 S1) was discovered independently by amateur astronomers Kaoru Ikeya and Tsutomu Seki, about 15 minutes apart, on September 18, 1965., at 19^h12^m, west of the star "Alphard" (α Hydrae) with an estimated magnitude of 8, appearing diffuse with condensation. On September 19 at 18^h57^m36^s it was confirmed by the Smithsonian Astrophysical Observatory from Woomera (Australia). From the outset it is recognized as a "suicide" or Kreutz, increasing its brightness rapidly. Thus, on October 1 it had an approximate magnitude of 5.5 and on the 12th of the same month, of 2; and a tail about five degrees in length. It passed through perihelion at 0.007786 a.u. del Sol on October 21, 1965 at 4^h24^m, being able to be seen in broad daylight, covering the solar disk with his hand. At that time it may have been magnitude -10 or -11. The comet's tail reached a length of 20 to 25 degrees in late October and early November. In its aphelion it moves away from the king star until 183.192214 u. to. Its period of revolution is 876.684262 years. There is a possibility that this comet was the return of the great comet X/1106 C1, which was seen in broad daylight across Europe.

Of the six comets discovered by Kaoru Ikeya, the 1966 R₁ (Ikeya-Everhart) is parabolic; the rest of very large periods:

• 1963 A1 (Ikeya) with a period of 932,490861 years.
• 1964 N1 (Ikeya) with a period of 391,431491 years.
• 1965 S1 (Ikeya-Seki) with a period of 876,684262 years.
• 1967 Y1 (Ikeya-Seki) with period of 89,488,683726 years.
• 153P/Ikeya-Zhang with a period of 373,425796 years.

Cometa Ikeya-Seki, October 1965. Author Jorge Cappato. On the right you see the fall of a meteorite.