C/1967 Y1 (Ikeya–Seki)
Discovery[1] | |
---|---|
Discovered by | Kaoru Ikeya Tsutomu Seki |
Discovery site | Japan |
Discovery date | 28 December 1967 |
Designations | |
1967n[2] 1968 I | |
Orbital characteristics[3] | |
Epoch | 18 March 1968 (JD 2439933.5) |
Observation arc | 676 days (1.85 years) |
Number of observations | 197 |
Aphelion | 4,020 AU |
Perihelion | 1.697 AU |
Semi-major axis | 2,011 AU |
Eccentricity | 0.99916 |
Orbital period | 90,185 years |
Inclination | 129.315° |
255.321° | |
Argument of periapsis | 70.864° |
Last perihelion | 25 February 1968 |
TJupiter | –1.02 |
Earth MOID | 1.0675 AU |
Jupiter MOID | 0.0276 AU |
Physical characteristics[4] | |
Comet total magnitude (M1) | 4.0 |
6.7 (1968 apparition) |
Comet Ikeya-Seki, formally designated as C/1967 Y1, is a retrograde non-periodic comet discovered by Kaoru Ikeya and Tsutomu Seki on 1967. It is the second comet discovered together by the two Japanese astronomers after C/1965 S1.[1]
Discovery and observations
[edit]C/1967 Y1 was the 14th comet discovered in 1967 when both Kaoru Ikeya and Tsutomu Seki spotted it as a 9th-magnitude object on the evening of December 28th.[5] The comet's position remained circumpolar throughout its last perihelion, thus giving astronomers a rare opportunity to observe it all night long.[5]
By 25 February 1968, the comet reached an apparent magnitude of 7.1 and developed a very faint tail.[6] Photometric spectroscopy of the comet's tail together with comets C/1968 L1 and C/1968 N1 has shown its forward scattering to be gray in the 3500–6300 Å spectrum, in contrast to the reddening of the dust tail seen in other comets.[7] The comet was last observed from the Kitt Peak Observatory on 4 November 1969.[4]
References
[edit]- ^ a b B. G. Marsden (2 January 1968). "Comet Ikeya-Seki (1967n)". Central Bureau for Astronomical Telegrams. 2046.
- ^ "Comet Names and Designations". International Comet Quarterly. Retrieved 5 December 2024.
- ^ "C/1967 Y1 (Ikeya–Seki) – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 5 December 2024.
- ^ a b G. W. Kronk (1999). Cometography: A Catalog of Comets. Vol. 5: 1960–1982. Cambridge University Press. pp. 200–205. ISBN 978-0-521-87226-3.
- ^ a b D. Milon (March 1968). "New Comet Ikeya-Seki 1967n". Strolling Astronomer. Association of Lunar and Planetary Observers: 209–211. Bibcode:1968StAst..20..209M.
- ^ M. J. Gainsford; D. A. Allen; G. S. Pearce (March 1968). "Observations of Comet Ikeya-Seki 1967n". The Astronomer. 4: 218–219. Bibcode:1968StAst..20..209M.
- ^ W. L. Gebel (August 1970). "Spectrophotometry of Comets 1967n, 1968b, and 1968c". The Astrophysical Journal. 161: 765–778. Bibcode:1970ApJ...161..765G. doi:10.1086/150577.
External links
[edit]- C/1967 Y1 at the JPL Small-Body Database