C / 1471 Y1
| C / 1471 Y1 [i] | |
|---|---|
| Properties of the orbit ( animation ) | |
| Orbit type | parabolic |
| Numerical eccentricity | 1.0 |
| Perihelion | 0.486 AU |
| Inclination of the orbit plane | 171 ° |
| Perihelion | March 1, 1472 |
| Orbital velocity in the perihelion | 60 km / s |
| history | |
| Explorer | |
| Date of discovery | December 21, 1471 |
| Older name | 1472 |
| Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . Please also note the note on comet articles . | |
C / 1471 Y1 was a comet that could be seen with the naked eye in 1471 and 1472 . It is counted among the " Great Comets " due to its extraordinary brightness .
Discovery and Visibility
This comet is reported in the records of many cultures, it is the best-documented comet since C / 1337 M1 , five historical texts from Asia alone and over two dozen European and Muslim texts report details. Most accounts agree that he was first sighted in the second half of December 1471. The Chronicles of the White Rose of York (1483) reports that it was first seen "two or three hours before sunrise ... four days before Christmas". At the time of its discovery it must have been an impressive object in the south-southeastern sky, as a Polish chronicle confirms. In Russia, too, a “big star” was observed with a “very long and broad beam” that was “spread out like the tail of a large bird”. This, as well as an Egyptian text, also report that from January the comet could be seen both in the evening sky in the west and in the morning sky in the east.
In Japan the comet was first seen on January 2nd with a 4-5 ° long tail . He was observed there until at least February 10th. In China and Korea , the comet was also seen from early January to February. By January 20th, the tail should have reached a length of 30 °.
In Italy , a tail of 36 ° longitude and 4 ° latitude was already observed in mid-January, and the comet's head was "almost as big as the moon". At this time, the comet was also observed by the German mathematician Regiomontanus , who estimated the angular extent of the length of the tail and the coma .
The Chinese, who recognized the apparition as a comet on January 15th, report that it "stretched across the sky" and appeared "even at noon" around January 22nd. At this time the comet must have passed very close to the earth and passed very quickly only about 15 ° past the north celestial pole . With this brightness, the comet must have been a truly grandiose spectacle at night.
After passing the earth, the comet faded again and in the course of February the worldwide observations then end before the comet passed its point closest to the Sun. It then moved away from the earth in the direction of the sun and could therefore not be observed again.
The comet reached a magnitude of −3 mag on January 23 .
Scientific evaluation
Regiomontanus tried to determine the distance and extent of the comet from its estimated parallaxes . Since he still adhered to the prevailing Aristotelian opinion that comets are phenomena of the earth's atmosphere , his calculated values were orders of magnitude too small. Nevertheless, his treatise De cometae magnitudine, longitudineque, ac de loco eius vero problemata XVI (1531) is the first scientific description of a comet in Europe.
Orbit
For the comet, due to the limited number of observations, only a parabolic orbit with limited precision could be determined, which is inclined by around 171 ° to the ecliptic . It thus runs almost in the same plane, but in the opposite sense (retrograde) as the planets through its orbit. In such an orbit, several close encounters with the planets are to be expected, which can influence the orbit of the comet.
At the point of the orbit closest to the sun ( perihelion ), which the comet passed around March 1, 1472, it was located at about 73 million km from the sun between the orbits of Mercury and Venus . It had already passed Jupiter about a year earlier on March 15, 1471 with a distance of only 0.87 AU . By January 22nd, 1472, it had come close to Earth to about 0.069 AU / 10.3 million km, making it one of the closest comets to Earth. This close proximity to the earth was also the reason for its observed brightness. By January 24th it had approached Venus up to about 42 million km and by February 25th it had approached Mercury up to 31 million km.
Before leaving the inner solar system , there were other relatively close passages of Venus (0.57 AU / April 23), Jupiter (1.4 AU / mid-June 1473) and Uranus (2.2 AU / August / September 1478) . The orbital eccentricity of the comet was reduced by about 0.001, especially due to the passage of Jupiter, but unfortunately, due to the uncertain initial data, no statement can be made whether the orbit is now definitely elliptical and how long the orbit time is. The comet is unlikely to return to the inner solar system, or will return many tens or hundreds of thousands of years.
See also
Individual evidence
- ^ A b D. AJ Seargent: The Greatest Comets in History: Broom Stars and Celestial Scimitars . Springer, New York, 2009, ISBN 978-0-387-09512-7 , pp. 102-104.
- ^ GW Kronk: Cometography - A Catalog of Comets, Volume 1. Ancient - 1799 . Cambridge University Press, 1999, ISBN 978-0-521-58504-0 , pp. 285-289.
- ^ Donald K. Yeomans: NASA JPL Solar System Dynamics: Great Comets in History. Retrieved June 6, 2014 .
- ↑ C / 1471 Y1 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 .