C / 1858 L1 (Donati)
| C / 1858 L1 (Donati) [i] | |
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Comet Donati on October 5, 1858
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| Properties of the orbit ( animation ) | |
| Orbit type | long-period |
| Numerical eccentricity | 0.9963 |
| Perihelion | 0.578 AU |
| Aphelion | 311.7 AU |
| Major semi-axis | 156.1 AU |
| Sidereal period | ~ 1951 a |
| Inclination of the orbit plane | 117.0 ° |
| Perihelion | September 30, 1858 |
| Orbital velocity in the perihelion | 55.3 km / s |
| history | |
| Explorer | Giambattista Donati |
| Date of discovery | June 2, 1858 |
| Older name | 1858 VI |
| Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . Please also note the note on comet articles . | |
C / 1858 L1 (Donati) , also called Donatischer Komet , was a comet that could be seen with the naked eye in 1858 . Due to its extraordinary brightness , it is counted among the " Great Comets ".
Discovery and observation
On the evening of June 2, 1858, Giambattista Donati discovered an inconspicuous comet with a telescope in Florence . News of the discovery quickly spread among European astronomers , but independent discoveries were made in the United States on June 30 and July 7. The comet's brightness increased steadily, but at dusk in early August the comet initially became increasingly difficult to observe.
In mid-August the observation situation improved again and the comet was estimated to have a brightness of 4.5 mag at that time . The first observations with the naked eye were probably made by Karl Christian Bruhns in Berlin on August 28th and September 2nd, when the brightness was 3 to 4 mag. Two weeks later, on September 17th, it had already reached 1.4 mag.
In September a tail also began to develop, growing from 1 ° longitude on September 1st to 25 ° longitude at the end of the month. The tail itself showed clear horizontal stripes (striae) from September 8th and was slightly curved. The comet's brightness was around 0 mag from late September to mid-October, and between September 22 and October 8 the comet was observed by several observers, including Johann Heinrich Mädler , Karl Christian Bruhns, Johann Friedrich Julius Schmidt , George Phillips Bond, and William Rutter Dawes even seen with telescopes in the daytime sky.
After passing through the perihelion, the comet developed not only a curved dust tail but also a straight plasma tail of increasing length, which on October 6th was 40 °. The dust tail also reached such a longitude on October 11, at the time of the comet's closest approach to Earth , while its latitude reached 10 to 16 °. The tail length then decreased rapidly and on October 17th it reached just 5 °.
The comet has also been seen by numerous explorers, travelers and adventurers around the world. David Livingstone observed the comet while in Mozambique and described the reaction of the natives to the sight. James Hector observed the comet on September 11 on an expedition to Canada and Francis Leopold McClintock on September 14 on an Arctic expedition. Between October 7 and November 5, Chinese astronomers also reported a comet in the shape of a large “broom star”.
From mid-October the comet could finally be observed preferably from the southern hemisphere , but its brightness was only about 4 mag towards the end of October. The last observation with the naked eye was made on November 11th. The comet could be observed telescopically until March 4, 1859 at the Cape of Good Hope .
The comet reached a magnitude of 0 to 1 mag on October 7th .
Effects on the zeitgeist
In the opinion of many contemporaries, Donati was one of the most impressive and beautiful comets (if not the most spectacular) of the 19th century . The extremely bright comet had a gracefully curved tail and inspired a number of paintings , poetry and satire , particularly in Great Britain and France . In the Far East, influences on the societies in Siam and Japan are particularly evident.
Comet Donati was a real media event in its day and made a lot of the news during September and October 1858. Newspapers and popular magazines reported on the fascination and excitement that the appearance of the comet caused in European society. They also provided astronomical information, while satirical magazines made fun of the cometary ecstasy that swept Britain and France. The comet also left its mark on the works or diaries of writers such as Charles Dickens , Nathaniel Hawthorne and Jules Verne .
Among the many paintings influenced by the appearance of the comet, it is worth noting William Dyce's haunting meditation on the time of Pegwell Bay, Kent - a Recollection of October 5th 1858 . It shows several members of his family collecting clams in the popular holiday resort near Ramsgate . The barely visible tail of Comet Donati is shown above the scene.
Even William Turner of Oxford , a good observer of natural phenomena, created with Donati's Comet combines an overwhelming work that ephemerality and timelessness.
King Mongkut of Siam, a scholar who could do astronomical calculations, also watched the comet and tried to eradicate the superstitious fears of his people by public speaking. In Japan, too, the comet was widely observed and interpreted both as a bad omen , since it appeared in a difficult time, and as a harbinger of better times.
Scientific evaluation
Towards the end of September 1858, a new era in comet research began when photographic images of a comet were first taken. This was the British photographer William Usherwood using his portrait - camera on September 27, 1858 and one night later the American astronomer William Cranch Bond at the Harvard College Observatory . The images on collodion plates only showed the lighter regions of the coma and parts of the tail. Only in 1881 was another comet photographed.
A special feature of this comet, which could only be seen telescopically, was the wealth of details in the inner coma . On September 15, 1858, something was first observed by Wilhelm Foerster , which he described as "a clear outflow". Even Arthur Auwers observed in the first half of October a "tuft or fan" of the comet nucleus in the direction of the sun went out. At the same time, six or seven envelopes were also observed around the comet's nucleus, which appeared to spread into the coma, weakening from the inside out.
A possible explanation for this could only be found with new knowledge about the structure of comets in the second half of the 20th century . It is believed that at one point on the comet's nucleus the relatively inactive surface was broken up by some process, thereby exposing deeper regions. Due to the rotation of the comet, this point was periodically exposed to solar radiation and during this time it reacted with violent outgassing. The moving gas clouds were formed into spiral arms by the rotation of the comet and blown away into expanding envelopes by the solar wind . On the basis of these observations, the astronomer Fred Whipple calculated a period of rotation for the comet's nucleus of around 4½ hours. This rotation would be unusually fast and at some point could lead to the unstable comet's core being gradually torn apart by the centrifugal forces .
Orbit
For the comet was from the observational data over a period of 270 days by George William Hill an elliptical orbit are determined that by around 117 ° to the ecliptic is tilted. 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 September 30, 1858, it was located at a distance of about 86.5 million km from the sun in the area between the orbits of Mercury and Venus . On October 10, it reached the closest approach to Earth at 0.54 AU / 80.5 million km , eight days later it passed Venus at a distance of only 13.2 million km and finally passed on October 31 to Mars in 89.2 million kilometers distance.
The comet moves on an extremely elongated elliptical orbit around the sun, which is almost perpendicular to the orbits of the planets. According to the railway elements , which are afflicted with a certain uncertainty, it could have appeared in antiquity around the year -107. During the last passage through the inner solar system in 1858, its orbital eccentricity was reduced slightly by 0.00035 and its semi-major axis from about 157 AU to about 145 AU, so that its orbital period was significantly reduced. When it reaches the point of its orbit furthest from the sun ( aphelion ) around the year 2730 , it will be around 43.2 billion km from the sun, almost 289 times as far as Earth and over 9½ times as far as Neptune . Its orbit speed in the aphelion is only about 0.10 km / s. The next perihelion of the comet will possibly take place around the year 3600.
More recently, Richard L. Branham calculated new and improved orbital elements for the comet using more than 2000 observation data between June 1858 and March 1859 and taking into account the interfering influences of all planets and other modern mathematical methods. Its determined values are 154.9 AU for the semi-major axis and the period of revolution 1927 a. According to his calculations, the comet will pass Earth again in 3759 at a distance of 0.84 AU.
The comet in lyrics
The great comet of 1858
Then came the climax! Oh that glorious hour!
The mighty Comet in its pride of power!
No sight like that had ever met my gaze!
No sight like that will living man amaze!
Beautiful vision! Feathery, graceful, bright,
A starry diamond in a veil of light!
La comète de 1858
Mystérieux navire au sillage de flamme,
Tu glisses dans les airs sans boussole et sans rame:
…
Oh! parmi les mortels, qui nous fera connaître
La nature, le fond, l'essence de ton être?
Chacun, sur ton passage accourant ici-bas,
Te regarde, t'admire, et ne te comprend pas.
The "Ode to the Bockbier" by Paul Heyse begins with the lines:
"In the year of salvation and that splendid comet that ripened us into the fifty-eighth blossom"
Trivia
The comet still inspires the namesake of racehorses to this day . One in Ireland drawn gelding was named 2006 "Donati's Comet".
See also
Web links
Individual evidence
- ↑ a b A. Gasperini, D. Galli, L. Nenzi: The worldwide impact of Donati's comet on art and society in the mid-19th century. In: The Rôle of Astronomy in Society and Culture Proceedings IAU Symposium , No. 260, 2011, pp. 340-345 ( arxiv : 1211.3859 ).
- ↑ a b c D. AJ Seargent: The Greatest Comets in History: Broom Stars and Celestial Scimitars . Springer, New York 2009, ISBN 978-0-387-09512-7 , pp. 131-136.
- ↑ Gary W. Kronk : Cometography - A Catalog of Comets, Volume 2. 1800-1899 . Cambridge University Press, 2003, ISBN 0-521-58505-8 , pp. 268-276.
- ^ Donald K. Yeomans: NASA JPL Solar System Dynamics: Great Comets in History. Retrieved June 17, 2014 .
- ↑ JM Pasachoff, RJM Olson, ML Hazen: The earliest comet photographs: Usherwood, Bond, and Donati 1858. In: Journal for the History of Astronomy , XXVII, 1996, pp. 129-145 ( bibcode : 1996JHA .... 27 ..129P ).
- ↑ C / 1858 L1 (Donati) 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 .
- ^ Richard L. Branham: A new orbit for comet C / 1858 L1 (Donati). In: Astronomische Nachrichten , Vol. 335 (2), 2014, pp. 135–141.
- ↑ the-racehorse.com. Retrieved September 11, 2014 .