C / 1962 C1 (Seki-Lines)

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C / 1962 C1 (Seki-Lines) [i]
Properties of the orbit ( animation )
Epoch:  April 6, 1962 ( JD 2,437,760.5)
Orbit type hyperbolic
s. Article text
Numerical eccentricity 1.0000033
Perihelion 0.031 AU
Inclination of the orbit plane 65.0 °
Perihelion April 1, 1962
Orbital velocity in the perihelion 238 km / s
history
Explorer Richard D. Lines, Tsutomu Seki
Date of discovery 4th February 1962
Older name 1962 III, 1962c
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . Please also note the note on comet articles .

C / 1962 C1 (Seki-Lines) is a comet that could be seen with the naked eye in 1962 . Some consider it one of the " great comets ".

Discovery and observation

This comet was first discovered by Richard D. Lines on the evening of February 3, 1962 (local time). He had driven into the desert about 50 km east of Phoenix, Arizona to observe the sky with a telescope when he found an unknown misty spot in the southern Milky Way . He was about to consult a star map when his wife and several friends came to keep him company. Everyone could see the object through the telescope and his wife noticed that it looked like a comet. When the star maps showed no object at that point, they all drove quickly back to Phoenix to notify the Lowell Observatory .

About seven hours later, shortly before midnight in Japan , Tsutomu Seki , who had already discovered a comet four months earlier, was also scanning the southern Milky Way with a telescope when he too found a blurred spot with a brightness of about 9 mag. At first he thought of a comet, but then thought it was a star cluster and ended his observations. The matter did not leave him alone and he went back to his telescope to check his sighting. Now he was able to confirm that it was a comet. To be on the safe side, he wanted to confirm his sighting the next evening before reporting. At first he could not find the comet and was already thinking of a deception, but then he found it in another place, where the comet had moved in the elapsed time. His sighting report finally arrived at the official site before Lines did. Since Lines had not provided sufficiently detailed information about his sighting, the confirmation from the Lowell Observatory one day after his first discovery was officially recognized for him, which is why the comet was called Seki-Lines and not Lines-Seki.

During the rest of the month the comet was observed intensively. a. by Robert Burnham, Jr. in Arizona and John Caister Bennett in South Africa , and also photographed, u. a. by George Van Biesbroeck at Yerkes Observatory and Elizabeth Roemer at Flagstaff . In mid-February the comet had reached its greatest southern declination , its brightness increased to about 5 mag by the end of the month and a small tail began to form.

From March 9, the comet could be observed with the naked eye. Its brightness continued to increase rapidly and by the end of the month already reached –1 mag, the comet's head appeared light yellow and the tail was 2-3 ° long. On 1 April, the comet came from the earth as seen in about 1.5 ° distance west of the sun over, but did not manage it with a pair of binoculars at daytime sky to watch. Only a few days later the comet could be found again at dusk . During April it was observed by numerous observers around the world. By the middle of the month the brightness had quickly decreased to 3 mag and by the end of the month it had already fallen to 7 mag. The length of the tail, on the other hand, had increased to 15-20 ° in the first half of April before it had almost disappeared again by the end of the month. As previously published in which some years comet C / 1957 P1 (Mrkos) was able to the phenomenon of parallel strips ( striae ) can be observed.

At the end of April the comet had reached its greatest northerly declination and a few days later began to approach the sun again as viewed from Earth. Until the end of May it could initially be observed visually and photographically. On July 27th, viewed from Earth, it passed the sun again to the north at a distance of 0.75 °. Photographs of him were not taken again until the end of October. The last observations were finally made on January 25, 1963 by Roemer.

The comet reached a maximum brightness of –2.5 mag.

Scientific evaluation

In March and April 1962, spectrographic observations of the comet were made at observatories in South Africa, France and Italy . High-resolution spectrograms were obtained that showed comet-typical emission lines of C 2 , C 3 , Na, O, NH, NH 2 , CN and CH.

Orbit

For the comet, a (temporarily) hyperbolic orbit could be determined from 92 observation data over a period of 352 days by Marsden , which is inclined by around 65 ° to the ecliptic . At the point of the orbit closest to the sun ( perihelion ), which the comet passed on April 1, 1962, it was only about 5 solar radii above its surface at a distance of 4.70 million km from the sun . Already on February 26th, it had reached the closest approach to earth with about 0.62 AU / 92.5 million km . On April 4th there was a second approach to Earth, this time only to about 1.01 AU / 151.2 million km and on April 30th the comet was still at a distance of about 70.6 million km past Venus .

Marsden, Sekanina and Everhart also examined the past situation and future evolution of the comet's orbit. Taking into account the gravitational influences of all planets , they found that the comet had already moved on an extremely elongated elliptical orbit around the sun before its passage through the inner solar system in 1962 . According to this, its orbit had an eccentricity very close to (but less than) 1 and a semi-major axis of around 40,000 AU, so that its orbit was around 8 million years. It may have been a “dynamic new” comet from the Oort cloud, or had only come close to the sun a few times before. Due to the gravitational pull of the planets, in particular by passing Uranus on January 31, 1957 at a distance of about 5 ⅓ AU and at Jupiter on April 1, 1962 at about 5 AU, the orbital eccentricity was about 0.999988 and the semi-major axis about 2840 AU so that its orbital period is now in the range of about 150,000 years.

See also

Web links

Individual evidence

  1. ^ John E. Bortle: International Comet Quarterly - The Bright-Comet Chronicles. Retrieved September 25, 2015 .
  2. ^ JR Hill, DA Mendis: On the Origin of Striae in Cometary Dust Tails. In: The Astrophysical Journal. Vol. 242, 1980, pp. 395-401, bibcode : 1980ApJ ... 242..395H .
  3. ^ GW Kronk, M. Meyer: Cometography - A Catalog of Comets. Volume 5: 1960-1982 . Cambridge University Press, Cambridge 2010, ISBN 978-0-521-87226-3 , pp. 68-75.
  4. ^ P. Moore, R. Rees: Patrick Moore's Data Book of Astronomy . Cambridge University Press, Cambridge 2011, ISBN 978-0-521-89935-2 , p. 271.
  5. ^ B. Warner: High resolution spectra of Comet Seki-Lines (1962c). In: The Observatory. Vol. 83, 1963, pp. 223-225, bibcode : 1963Obs .... 83..223W .
  6. ^ P. Swings, Ch. Fehrenbach: Le specter de la comète "Seki-Lines" (1962c). In: Publications de l'Observatoire de Haute-Provence. Vol. 6, No. 12, 1962.
  7. ↑ P. Maffei: Osservazioni di comete - Nota IV. Osservazioni spettroscopiche delle comete 1960 i, 1960 n, 1961 e, 1962 c. In: Memorie della Società Astronomia Italiana. Vol. 34, 1963, pp. 249-256, bibcode : 1963MmSAI..34..249M .
  8. ↑ NASA JPL Small-Body Database Browser: C / 1962 C1. Retrieved September 29, 2015 .
  9. ↑ SOLEX 11.0 A. Vitagliano. Archived from the original on September 18, 2015 ; accessed on May 2, 2014 .
  10. ^ BG Marsden, Z. Sekanina, E. Everhart: New Osculating Orbits for 110 Comets and Analysis of Original Orbits for 200 Comets. In: The Astronomical Journal. Vol. 83, no. 1, 1978, pp. 64-71 doi: 10.1086 / 112177 .