C / 1941 B2 (de Kock-Paraskevopoulos)
| C / 1941 B2 (de Kock-Paraskevopoulos) [i] | |
|---|---|
| Properties of the orbit ( animation ) | |
| Orbit type | long-period |
| Numerical eccentricity | 0.99910 |
| Perihelion | 0.790 AU |
| Aphelion | 1759 AE |
| Major semi-axis | 880 AU |
| Sidereal period | ~ 26,000 a |
| Inclination of the orbit plane | 168.2 ° |
| Perihelion | January 27, 1941 |
| Orbital velocity in the perihelion | 47.4 km / s |
| history | |
| Explorer | R. P. de Kock , J.S. Paraskevopoulos et al. a. |
| Date of discovery | January 15, 1941 |
| Older name | 1941 IV, 1941c |
| Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . Please also note the note on comet articles . | |
C / 1941 B2 (de Kock-Paraskevopoulos) is a comet . It could be seen with the naked eye in 1941, especially in the southern hemisphere , and is considered by some to be one of the " great comets ".
Discovery and observation
The amateur astronomer Reginald Purdon de Kock wanted to observe a variable star in Paarl ( South Africa ) on the morning of January 15, 1941 , when he discovered this comet. The head of the comet was conspicuous and the tail already developed to a length of ½ ° . The brightness was around 6 mag. de Kock informed the Royal Observatory at the Cape of Good Hope , where the discovery was confirmed in the following days.
Because of its brightness, there were also independent discoveries in Australia on January 20 and 21 , including a. by John Francis Skjellerup , so that the comet was already known there under the name "Barnes-Skjellerup". John Stefanos Paraskevopoulos , an astronomer from Bloemfontein , also discovered the comet independently on January 23 with a 5 ° long tail and reported his discovery to the Harvard College Observatory in the United States , so that the comet there under the name "Comet Paraskevopoulos ”became known. Due to the turmoil of the war, news of de Kock's first discovery had initially not reached any countries outside Europe. Other independent discoveries were made in South America and New Zealand on January 23rd and 24th.
The comet quickly approached the sun and earth , so that its brightness continued to increase. On January 27, the comet reached its greatest southern declination . Two days later the comet reached its closest approach to Earth and appeared in the following days with a brightness of up to 2 mag with a tail length of still 5 °.
At the beginning of February the comet moved away from the sun and earth again, but the brightness decreased only slowly, in the middle of the month it was still 5 mag. When the comet could no longer be seen with the naked eye towards the end of the month, the tail length was still 1–2 °. The comet continued to be observed telescopically and photographically as it approached the sun. On the evening of March 29, George Van Biesbroeck made his last observation at the Yerkes Observatory at a low altitude above the horizon.
After the comet had passed the Sun at a distance of only 0.6 ° from Earth on the morning of April 28th, it could only be observed on four occasions in July and September. The last observation at the Lick Observatory took place on September 17th at a brightness of 17 mag.
The comet reached a maximum brightness of 2 mag.
Orbit
For the comet, Brian Marsden was able to determine an elongated elliptical orbit with limited accuracy from 130 observation data over a period of 241 days , which is inclined by around 168 ° to the ecliptic . The comet thus runs in the opposite direction (retrograde) like the planets through its orbit. At the point of the orbit closest to the sun ( perihelion ), which the comet passed on January 27, 1941, it was located at a distance of 118.2 million km from the sun in the area of the orbit of Venus . As early as December 7, 1940, it had passed Mars at a distance of about 63.7 million km and on December 21, Venus was about 55.0 million km away. Two days after the perihelion, the closest approach to earth was reached on January 29, 1941 with only about 0.27 AU / 39.7 million km . This relatively close passage was the reason for its observed brightness.
The comet moves in an extremely elongated elliptical orbit around the sun. After an earlier attempt by George Van Biesbroeck to determine the future orbit of the comet, Marsden, Sekanina and Everhart examined the past situation and future evolution of the comet's orbit. According to the orbital elements , which are afflicted with a certain degree of uncertainty, its orbit before its passage through the inner solar system in 1941 still had an eccentricity of about 0.9984 and a semi-major axis of about 495 AU, so that its orbit period was about 11,000 years. Due to the gravitational pull of the planets, especially due to the relatively close passage of Jupiter on May 17, 1941 at a distance of about 3 ⅓ AU, the orbital eccentricity was increased to about 0.9991 and the semi-major axis to about 890 AU, so that its orbital period is increased to increased about 26,500 years.
See also
Web links
- Image of the comet by G. Van Biesbroeck on February 4, 1941
- Image of the comet by G. Van Biesbroeck on February 15, 1941
Individual evidence
- ^ John E. Bortle: International Comet Quarterly - The Bright-Comet Chronicles. Retrieved September 25, 2015 .
- ^ TP Cooper: A history of comet discovery from South Africa. In: Monthly Notes of the Astronomical Society of Southern Africa. Vol. 62, 2003, pp. 170-179 ( bibcode : 2003MNSSA..62..170C ).
- ^ Gary W. Kronk : Cometography - A Catalog of Comets. Volume 4: 1933-1959 . Cambridge University Press, Cambridge 2009, ISBN 978-0-521-58507-1 , pp. 126-133.
- ^ P. Moore, R. Rees: Patrick Moore's Data Book of Astronomy . Cambridge University Press, Cambridge 2011, ISBN 978-0-521-89935-2 , p. 271.
- ↑ C / 1941 B2 (de Kock-Paraskevopoulos) in the Small-Body Database of the Jet Propulsion Laboratory (English).
- ↑ SOLEX 11.0 A. Vitagliano. Archived from the original on September 18, 2015 ; accessed on May 2, 2014 .
- ^ G. Van Biesbroeck: The orbit of comet 1941c-1941 IV (de Kock-Paraskevopoulos). In: Communications of the Lunar and Planetary Laboratory. Vol. 8, Part 5, 1970, pp. 333-335 PDF; 481 kB .
- ^ 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 .