C / 1882 F1 (Wells)

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C / 1882 F1 (Wells) [i]
Properties of the orbit ( animation )
Period:  June 20, 1882 ( JD 2,408,616.5)
Orbit type long-period
Numerical eccentricity 0.9999936
Perihelion 0.061 AU
Aphelion 19135 AE
Major semi-axis 9567 AE
Sidereal period ~ 936,000 a
Inclination of the orbit plane 73.8 °
Perihelion June 11, 1882
Orbital velocity in the perihelion 170.9 km / s
history
Explorer Charles S. Wells
Date of discovery March 18, 1882
Older name 1882 I, 1882a
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . Please also note the note on comet articles .

C / 1882 F1 (Wells) was a comet that could be seen with the naked eye in 1882 . 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 on the morning of March 18, 1882 by Charles S. Wells at the Dudley Observatory in Albany (New York) and described by him as "small and bright". At first nothing changed and Lewis Boss, the director of the Dudley Observatory, noted two days after the discovery that the comet looked "like a large comet in miniature". Its brightness at this point was around 8 mag.

The comet was observed extensively telescopically during April as its distance from the Earth and the Sun decreased. In the second half of May the comet reached its closest distance to Earth and initially moved even further towards the sun. Towards the end of the month, the increasing brightness made it possible to observe with the naked eye for the first time; the tail had reached a length of almost 1 °.

The comet moved south across the sky from the beginning of June and was rapidly approaching the sun, increasing its brightness to around 0 mag, but it never became such a conspicuous object in the sky that it would have attracted general attention . This was because it was only visible to observers in the northern hemisphere for a short time during the twilight . At that time, however, several astronomers managed to observe the comet in the daytime sky next to the sun. In Albany, shortly before noon on June 6th, the comet could be seen with difficulty with the passage instrument. Even Edward Walter Maunder was him on June 8 with a telescope at the Royal Observatory watch as he is a similar phenomenon as the planet Mars offered while Johann Friedrich Julius Schmidt him in Athens saw the afternoon of June 10 when he was 2 , 8 ° from the edge of the sun.

On the evening of June 10 at around 11:40 p.m. UT , the comet passed the Sun at a distance of 2.6 ° to observers on Earth and passed the point of its orbit closest to the Sun about an hour later. It then moved east in the sky and finally became visible to observers in the southern hemisphere , where it was from June 14th by William Henry Finlay at the Royal Observatory at the Cape of Good Hope and from June 15th by John Tebbutt in Windsor (New South Wales) in Australia . At this time the brightness had decreased to 2 mag and its tail was still about 2 ° in length.

On June 17, a long twilight tail was reported to extend up to 40-45 degrees from the position of the comet's head. However, this seems to have been a short-lived phenomenon. By the beginning of July the brightness had decreased to 6 mag and the comet could no longer be observed with the naked eye. The last sighting took place on August 16, 1882.

The comet achieved a maximum brightness of about 0 mag and, during its daytime appearance, of perhaps -6 mag.

Scientific evaluation

C / 1882 F1 was the first comet in which the presence of sodium could be detected by spectroscopic studies .

For all comets investigated up to that point, only characteristic lines of hydrocarbon compounds could be detected in the spectrum in addition to reflected or scattered sunlight. However, these comets were not very close to the sun. Comet Wells came close to the Sun to less than 10 million km, which apparently caused a new effect in its emitted light. In the first half of April the comet's spectrum was still “normal”, but as the sun got closer, the hydrocarbon bands faded completely and the spectrum of the comet's light resembled the continuum of a star. This unusual behavior has been closely observed. At the end of May, the yellow sodium D line was detected for the first time in the spectrum, which by the beginning of June became so strong that it outshone all other emissions and the light of the comet became practically monochromatic. Sir William Huggins succeeded in documenting the comet's unusual spectrum in a 1 ¼ hour photograph .

Orbit

For the comet, a very precise elliptical orbit could be determined from 28 observations over a period of 112 days , which is inclined by around 74 ° to the ecliptic . At the point of the orbit closest to the sun ( perihelion ), which the comet passed on June 11, 1882, it was only about 12 solar radii above its surface at a distance of 9.1 million km from the sun . Already on May 21, it had reached its closest approach to earth at a distance of about 0.89 AU / 133.2 million km, while on June 18 it reached a second approach to about 0.95 AU / 141.7 Million km. On July 5th, the comet passed Venus at a distance of only 40.5 million km and on August 14th it passed Mars at a distance of 45.6 million km, too.

Before approaching the inner solar system in 1882, the comet was still moving on an extremely elongated elliptical orbit with an orbital eccentricity close to 1 and a semi-major axis of about 7000 AU, so that its orbital period was about 600,000 years. It may have been a “dynamic new” comet from the Oort cloud, or had only come close to the sun a few times before. Due to the gravitational pull of the planets, the eccentricity was slightly reduced to around 0.99995 and the semi-major axis of the orbit to around 1280 AU, so that the comet's orbit period was reduced to around 45,000 years.

See also

Individual evidence

  1. ^ G. Wise: Civic Astronomy: Albany's Dudley Observatory, 1852-2002 . Springer, Dordrecht 2004, ISBN 978-90-481-6702-9 , pp. 69-70, doi: 10.1007 / 978-1-4020-2678-2 .
  2. ^ A b A. M. Clerke: A Popular History of Astronomy During the Nineteenth Century . Cambridge University Press, Cambridge 2010, ISBN 978-1-108-01432-8 , pp. 398-400.
  3. ↑ GW Kronk: Cometography - A Catalog of Comets, Volume 2. 1800-1899 . Cambridge University Press, Cambridge 2003, ISBN 0-521-58505-8 , pp. 496-501.
  4. ^ P. Moore, R. Rees: Patrick Moore's Data Book of Astronomy. Cambridge University Press, Cambridge 2011, ISBN 978-0-521-89935-2 , p. 270.
  5. ^ John E. Bortle: International Comet Quarterly - The Bright-Comet Chronicles. Retrieved July 24, 2015 .
  6. ^ DAJ Seargent: The Greatest Comets in History: Broom Stars and Celestial Scimitars . Springer, New York 2009, ISBN 978-0-387-09512-7 , p. 234.
  7. ↑ C / 1882 F1 (Wells) in the Small-Body Database of the Jet Propulsion Laboratory (English).Template: JPL Small-Body Database Browser / Maintenance / Alt
  8. ↑ SOLEX 11.0 A. Vitagliano. Archived from the original on September 18, 2015 ; accessed on May 2, 2014 .
  9. ^ EH Bilo, I. van Houten-Groeneveld: The original values ​​of 1 / a for 17 cometary orbits. In: Bulletin of the Astronomical Institutes of the Netherlands. Vol. 15, 1960, pp. 155-162, bibcode : 1960BAN .... 15..155B .
  10. ^ Z. Sekanina: Future orbits for ten comets of the General Catalog of Original and Future Comet Orbits. In: Bulletin of the Astronomical Institute of Czechoslovakia. Vol. 18, No. 1, 1967, pp. 1–14, bibcode : 1967BAICz..18 .... 1S .