C / 568 O1

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C / 568 O1 [i]
Properties of the orbit ( animation )
Epoch:  29th August 568 ( JD 1,928,759.2)
Orbit type parabolic
Numerical eccentricity 1.0
Perihelion 0.87 ± 0.01 AU
Inclination of the orbit plane 4.0 ± 1 °
Perihelion August 27, 568 ± 0.5 days
Orbital velocity in the perihelion 45 km / s
history
Explorer
Date of discovery July 28, 568
Older name 568
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . Please also note the note on comet articles .

C / 568 O1 is a comet that could be seen with the naked eye in 568 . It is counted among the " Great Comets " due to its extraordinary brightness .

Discovery and observation

The Chinese chronicle Suí Shū from the 7th century reports that on July 28, 568 a "guest star" appeared in the sky. He was first seen in the constellation Libra , probably on the evening of that day. Furthermore, there is no evidence that this guest star continued to be observed over the course of the following month, and various astronomers suggested that it may have been a nova .

The same chronicle and also the text Běi Zhōu Shū report that in August of that year a “guest star” in the constellation Scorpio was seen in the evening sky . It appeared white, the color of "loose cotton". It grew in size and moved east. In the course of September it formed a tail 40 ° in length and resembled “a piece of cloth”. It moved through the constellations Eagle , Pegasus and Andromeda until October , then became smaller again and was probably last observed after 69 days on November 10th in the constellation Aries .

In his cometography, Pingré refers to two Chinese sources and reports two comets, one in July and a second from September. Even Williams calls these sources and two more, which report of Kometensichtungen in July and August. All of these reports likely refer to the same comet.

The comet reached a brightness of 0 mag around September 25th .

Orbit

The first calculations of an orbit for this comet were carried out by Hind and Laugier in the mid-19th century . They only used the observations from late September to mid-November. For the first time, Hasegawa was able to link the observation of the "guest star" from July 28th with the other data from the beginning of September to November, after he had determined a somewhat uncertain parabolic orbit for the comet from 4 observations over 63 days , which was around 4 ° against the ecliptic is inclined. It thus runs through its orbit almost in the same plane as the planets . At the point of the orbit closest to the sun ( perihelion ), which the comet passed around August 27, 568, it would have been about 130 million km from the sun between the orbits of Venus and Earth . By August 23, it would have come close to Venus to around 27 million km. By September 25th, it could have approached Earth to around 0.09 AU / 14 million km, making it one of the 30 closest comets to Earth in historical times. This close proximity to the earth could have been the reason for its observed brightness. A month later, around October 24th, it could have approached Mars within about 47 million km.

Due to the uncertain initial data, no statement can be made as to whether and, if so, when the comet could return to the inner solar system .

See also

Individual evidence

  1. ^ GW Kronk: Cometography - A Catalog of Comets, Volume 1, Ancient - 1799. Cambridge University Press, Cambridge 1999, ISBN 978-0-521-58504-0 , pp. 92-93.
  2. ^ AG Pingré: Cométographie ou Traité historique et théorique des comètes. Tome I. Imprimerie Royale, Paris 1783, pp. 322–323 ( PDF; 56.49 MB ).
  3. ↑ J. Williams: Observations of Comets, from BC 611 to AD 1640. Strangeways and Walden, London 1871, pp. 34, 36, 37 ( PDF, 20.93 MB ).
  4. ↑ DK Yeomans: NASA JPL Solar System Dynamics: Great Comets in History. Accessed June 30, 2016 .
  5. ↑ JR Hind: Letter to the editor. In: Astronomical News. Vol. 23, No. 551, 1846, pp. 377-378.
  6. ^ PAE Laugier: Mémoire sur quelques comètes anciennes. In: Comptes rendus hebdomadaires des séances de l'Académie des sciences. Tome 22. Bachelier, Paris 1846, pp. 148–156.
  7. ^ I. Hasegawa: Orbits of Ancient and Medieval Comets. In: Publications of the Astronomical Society of Japan. Vol. 31, 1979, pp. 257-270 ( bibcode : 1979PASJ ... 31..257H ).
  8. ↑ C / 568 O1 in the Small-Body Database of the Jet Propulsion Laboratory (English).
  9. ↑ Historic Comet Close Approaches Prior to 2006. NASA, accessed July 5, 2016 (English).
  10. ↑ A. Vitagliano: SOLEX 11.0. Archived from the original on September 18, 2015 ; accessed on May 2, 2014 .