C / 1910 A1 (Great January Comet)

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C / 1910 A1 (Great January Comet) [i]
Comet 1910 A1.jpg
Properties of the orbit ( animation )
Epoch:  January 9, 1910 ( JD 2,418,680.5)
Orbit type long-period
Numerical eccentricity 0.999995
Perihelion 0.129 AU
Aphelion 51590 AE
Major semi-axis 25795 AE
Sidereal period > 4 million a
Inclination of the orbit plane 138.8 °
Perihelion January 17, 1910
Orbital velocity in the perihelion 117.3 km / s
history
Explorer
Date of discovery January 12, 1910
Older name 1910 I, 1910a
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . Please also note the note on comet articles .

C / 1910 A1 (Great January Comet ) (also called daylight comet ) was a comet that could be seen with the naked eye during the day in 1910 . Due to its extraordinary brightness, it is counted among the " Great Comets ".

Discovery and observation

At the beginning of 1910, astronomers around the world were eagerly preparing for the predicted return of Halley's Comet , but before that another comet appeared that would overshadow it.

The first who saw these comets were three workers in a diamond mine in the Transvaal in the dawn of January 12 1910, when he already has a brightness like -1 had. However, they did not report their discovery, probably because they thought the authorities already knew about it. Three days later, several railroad workers in Copier Junction in Orange Free State were able to observe the comet for 20 minutes. They mistook it for the expected Halley's Comet and the station master reported the event to a newspaper. The director of the Transvaal Observatory Robert Innes was the first astronomer to learn about this comet through a phone call from this newspaper editor . Innes was only able to see the comet himself on the morning of January 17th, after which the news of a newly appeared bright comet quickly spread worldwide.

At noon on the same day, Innes was able to observe the comet in the bright sky with the naked eye 4.5 ° next to the sun , at the time it had a brightness of -4 mag. He described it as a snow-white object about 1 ° long and brighter than Venus in its greatest splendor. The following day there were further daytime observations of the comet in Vienna , Algiers and Rome , and on January 19, astronomers at the observatory in Santiago de Chile observed the comet for seven hours from morning to evening when it was about 8 ° from the Sun. was standing. The comet was also observed during the day in Cambridge , the Lick Observatory and in Milan .

After the comet passed the Sun on January 17, it moved northward in the sky, making it clearly visible to observers in the northern hemisphere . It was widely observed by the public in Europe and North America . Many observers who later recalled seeing Halley's Comet were actually describing January's comet. On January 22nd, the comet appeared to an observer in Sweden with a curved tail of 25 ° longitude and 5 ° latitude at dusk, and tail lengths of 30 to 50 ° were estimated by the end of the month.

The comet gradually faded as it moved away from the sun and earth , 6 mag was reached on February 12, 8 mag in early March and 11 mag in early April. The last observation was on July 9th when it probably just hit 14 mag.

The comet reached a magnitude of 1 to 2 mag on January 30th . According to other information, the maximum brightness reached -4 mag.

Effects on the zeitgeist

Especially with the expectation of Halley's Comet in the same year (which, however, would not appear until a few months later), the public in Europe and North America was interested in everything on the subject of "comets". The Great January Comet was therefore observed by many people (and often confused with Halley's Comet).

Not all observers accepted the sudden appearance of the comet with calmness. On the coast of Portugal , people gathered at sunset to watch him emerge from the fading dusk - not all out of admiration, many also crossed themselves out of fear.

A newspaper report on Jan. 27 put the blame for a severe winter in parts of Europe at the time on the comet and predicted further dire consequences in the near future.

According to a report in the New York Times , the appearance of the comet sparked extreme fear among rural Russian populations , who viewed it as a portent of a great war in the Far East or the end of the world. The populations in North Africa and India were also seen as vulnerable to similar fears.

Scientific evaluation

The January comet of 1910 was extremely rich in dust. Spectrograms showed a continuous spectrum through scattered sunlight not only around the core , but also far into the tail. None of the usual emission lines could be determined. However, strong sodium emission lines have probably been observed for the first time on a comet . This phenomenon of a tail made of neutral sodium could only be analyzed much later on comet C / 1995 O1 (Hale-Bopp) . The presence of sodium along with the strong scattered sunlight also explains the description of the comet's color as yellow or even red, as several observers reported.

The high dust content of the comet's tail also led to striae in the tail, which was shaped like a curved horn. On January 27th, next to the curved tail, a shorter, straight tail could be seen, but it was probably also a dust tail. A plasma tail did not develop until the sodium emission lines disappeared, and after January 26th the usual cometary bands were also visible in the spectrum. At the beginning of February there was also a small counter-tail on a photograph.

Orbit

In 1982, Manoel Soares de Mello e Simas was able to determine an extremely elongated elliptical orbit that is inclined by around 139 ° to the ecliptic for the comet from around 400 observation data over a period of 180 days . 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 through on January 17th, it was located at a distance of 19.3 million km from the Sun, well within the orbit of Mercury . On the next day, January 18, it reached the closest approach to Earth with 0.86 AU / 128.4 million km . Another day later, on January 19th, it first passed Venus at a distance of 86.5 million km and then passed Mercury at a distance of 22.5 million km.

The comet's appearance in 1910 was possibly the first visit of this “dynamic new” comet from the Oort cloud to the inner solar system . After the orbital elements , which were afflicted with a certain degree of uncertainty, the force of attraction of the planets reduced its orbital eccentricity to around 0.999913 and its semi-major axis to around 1500 AU, so that its orbital period was significantly reduced. So it will possibly return after 50,000–60,000 years.

See also

Web links

Individual evidence

  1. 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. 142-146.
  2. ^ A b Peter Grego: Blazing a Ghostly Trail: ISON and Great Comets of the Past and Future . Springer, Cham 2013, ISBN 978-3-319-01774-7 , pp. 124-128.
  3. ^ Donald K. Yeomans: NASA JPL Solar System Dynamics: Great Comets in History. Retrieved September 19, 2014 .
  4. ^ P. Moore, R. Rees: Patrick Moore's Data Book of Astronomy . Cambridge University Press, Cambridge 2011, ISBN 978-0-521-89935-2 , p. 271.
  5. C / 1910 A1 (Großer Januarkomet) in the Small-Body Database of the Jet Propulsion Laboratory (English).
  6. SOLEX 11.0 A. Vitagliano. Archived from the original on September 18, 2015 ; accessed on May 2, 2014 .