C / 1847 C1 (Hind)
| C / 1847 C1 (Hind) [i] | |
|---|---|
| Properties of the orbit ( animation ) | |
| Orbit type | long-period |
| Numerical eccentricity | 0.999910 |
| Perihelion | 0.0426 AU |
| Aphelion | 946.5 AU |
| Major semi-axis | 473.3 AU |
| Sidereal period | ~ 10,000 a |
| Inclination of the orbit plane | 48.7 ° |
| Perihelion | March 30, 1847 |
| Orbital velocity in the perihelion | 204 km / s |
| history | |
| Explorer | JR Hind |
| Date of discovery | February 6, 1847 |
| Older name | 1847 I. |
| Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . Please also note the note on comet articles . | |
C / 1847 C1 (Hind) was a comet that could be seen with the naked eye in 1847 . It is counted by some among the " Great Comets " less because of its brightness in the night sky than because of its telescopic visibility in the daytime sky .
Discovery and observation
The comet was discovered by John Russell Hind in London on the evening of February 6, 1847 , when it was still a very faint object. However, the discovery report only reached the other observatories with a delay, so that Hind remained the only observer of the comet for over two weeks.
The comet continued to move closer to the sun and earth , from the beginning of March it could also be observed with the naked eye and began to develop a constantly growing tail . By the middle of the month the brightness had increased to about 4 mag and the length of the tail to about 4–5 ° . Towards the end of March the comet was getting closer and closer to the sun and could therefore no longer be observed for a few days. On March 30, at around 0:26 a.m. UT , the comet passed the Sun at a distance of only 0.8 ° from Earth and then began to move away again.
Hind was able to find the comet at noon on March 30th with a telescope and an attenuation filter in the daytime sky; by the evening of the day the comet had moved almost 2.5 ° from the sun, then reversed its apparent direction of movement and moved towards it again. On March 31, at around 11:04 p.m. UT, it passed the sun a second time, only 0.7 ° away from Earth. The comet thus became the first daylight comet that could only be observed with optical aids.
The comet then moved slowly away from the sun from the earth and was only found again on April 22nd by Johann Gottfried Galle in Berlin at dusk, two days later the last observations were made by Galle and Andrew Graham in Ireland .
The comet reached a maximum brightness of perhaps -4 mag during its appearance in the daytime sky.
Orbit
From 160 observations over a period of 77 days, only a limited precise elliptical orbit could be determined for the comet, which is inclined by around 49 ° to the ecliptic . At the point of the orbit closest to the sun ( perihelion ), which the comet passed on March 30, 1847, it was only about 8 solar radii above its surface at about 6.37 million km from the sun. A week earlier, on March 23, it had already reached its closest approach to Earth at a distance of around 0.84 AU / 125.2 million km. On March 25, the comet passed Mercury at a distance of 33.4 million km , and finally on April 8th it passed Venus at a distance of 75.4 million km.
The comet moves in an extremely elongated elliptical orbit around the sun. According to the orbital elements , which are afflicted with a certain uncertainty, when the comet appeared in 1847 the eccentricity of its orbit was not significantly changed by the gravitational pull of the planets. The semi-major axis was, however, shortened slightly from about 415 AU to about 375 AU, so that its orbital period was reduced from about 8300 years to about 7300 years.
See also
Individual evidence
- ^ DAJ Seargent: The Greatest Comets in History: Broom Stars and Celestial Scimitars . Springer, New York 2009, ISBN 978-0-387-09512-7 , p. 233.
- ↑ GW Kronk: Cometography - A Catalog of Comets, Volume 2. 1800-1899 . Cambridge University Press, Cambridge 2003, ISBN 0-521-58505-8 , pp. 171-174.
- ^ John E. Bortle: International Comet Quarterly - The Bright-Comet Chronicles. Retrieved July 23, 2015 .
- ↑ C / 1847 C1 (Hind) 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 .