C / 2007 F1 (LONEOS)
| C / 2007 F1 (LONEOS) [i] | |
|---|---|
| Properties of the orbit ( animation ) | |
| Orbit type | hyperbolic |
| Numerical eccentricity | 1.000086 |
| Perihelion | 0.402 AU |
| Inclination of the orbit plane | 116.1 ° |
| Perihelion | October 28, 2007 |
| Orbital velocity in the perihelion | 66.4 km / s |
| history | |
| Explorer | Brian A. Skiff , LONEOS |
| Date of discovery | March 19, 2007 |
| Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . Please also note the note on comet articles . | |
C / 2007 F1 (LONEOS) is a comet that could be observed with the naked eye in 2007 .
Discovery and observation
The comet was discovered on March 19, 2007 as part of the LONEOS project by BA Skiff on images taken by the 0.59 m telescope at Lowell Observatory in Arizona . The brightness was about 19.5 mag and the comet was still about 3.7 AU from the sun at that time . The discovery was confirmed in the following days by further observations and after two days Brian Marsden was able to carry out a preliminary orbit calculation.
The comet could initially be observed until May, when it was too close to the sun for observers on earth . He could not be found again until the end of September. In mid-October it had reached a brightness of 6 mag, more than initially expected. Sightings with the naked eye were only possible under favorable conditions. In the northern hemisphere , the comet could only be observed until the end of October at a brightness of just under 5 mag.
As a result, the comet was observed even further in the southern hemisphere , but the brightness was already decreasing again, in mid-November it was already weaker than 8 mag. Although the comet had never developed an impressive tail , an observer in Australia was able to observe a slight increase in brightness of the comet on November 9, combined with a spectacular development of the tail to a length of more than 5 °. The following evening the comet had returned to its “normal” appearance.
The comet could be observed telescopically until the beginning of December.
Orbit
For the comet, a hyperbolic orbit could be determined from 198 observation data over a period of 217 days , which is inclined by around 116 ° to the ecliptic . The comet's orbit is thus steeply inclined compared to the orbits of the planets and its orbit runs in the opposite direction ( retrograde ) to them. At the point closest to the Sun ( perihelion ), which the comet passed on October 28, 2007, it was about 60.2 million km from the Sun and was thus in the area between the orbits of Mercury and Venus . Already on October 21st, the comet had approached Venus up to approx. 95.0 million km and on October 25th, Mercury up to approx. 43.6 million km. The closest distance to the earth was reached on October 28, at around 107.0 million km (0.72 AU). The comet did not come close to Mars .
According to the orbital elements, which are afflicted with a certain uncertainty, as they are specified in the JPL Small-Body Database and which do not take into account non-gravitational forces on the comet, the comet was still moving on an extremely elongated elliptical orbit long before its passage through the inner solar system with an eccentricity of around 0.99967 and a semi-major axis of around 1230 AU, so that its period of revolution was around 43,000 years. Due to the gravitational pull of the planets, in particular due to the relatively close passages of Jupiter on August 16, 2005 at a distance of about 5 ¼ AU, at Saturn on October 8, 2006 in about 5 ½ AU distance, and one more time at Jupiter on 10. January 2008 in about 4 ¾ AU distance and on Saturn on January 13, 2010 in almost 8 AU distance, its orbital eccentricity was increased to about 1.000019, so that it now leaves the solar system on a hyperbolic orbit.
The orbital elements, as stated by S. Yoshida on his homepage, and which also take non-gravitational forces into account, approximately confirm the values given above regarding the comet's orbit before it approaches the inner solar system (orbital period about 42,000 years). For its future orbit, however, there is still a more hyperbolic orbit with an eccentricity of around 1,00014. The orbit elements given by S. Nakano lead to roughly the same statements.
See also
Web links
- C / 2007 F1 (LONEOS) Seiichi Yoshida's Home Page (English)
Individual evidence
- ↑ B. Marsden: MPEC 2007-F52: COMET C / 2007 F1 (LONEOS). In: Minor Planet Electronic Circular. IAU, March 21, 2007, accessed August 8, 2020 .
- ↑ Comet LONEOS C / 2007 F1. In: Kometen.info. December 24, 2007, accessed August 8, 2020 .
- ^ DAJ Seargent: Weird Comets and Asteroids: The Strange Little Worlds of the Sun's Family . Cham 2017, ISBN 978-3-319-56557-6 , pp. 161-163.
- ↑ C / 2007 F1 (LONEOS) in the Small-Body Database of the Jet Propulsion Laboratory (English).
- ↑ A. Vitagliano: SOLEX 12.1. Retrieved July 9, 2020 .
- ↑ S. Yoshida: C / 2007 F1 (LONEOS). In: Seiichi Yoshida's Home Page. February 27, 2017, accessed August 8, 2020 .
- ↑ S. Nakano: NK 1548: C / 2007 F1 (LONEOS). In: OAA computing section circular. OAA Computing and Minor Planet Sections, November 15, 2007, accessed August 8, 2020 .