C / 1911 O1 (Brooks)

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C / 1911 O1 (Brooks) [i]
Comet Brooks on September 29, 1911
Comet Brooks on September 29, 1911
Properties of the orbit ( animation )
Epoch:  October 11, 1911 ( JD 2,419,320.5)
Orbit type long-period
Numerical eccentricity 0.9970
Perihelion 0.489 AU
Aphelion 326.3 AU
Major semi-axis 163.4 AU
Sidereal period ~ 2090 a
Inclination of the orbit plane 33.8 °
Perihelion October 28, 1911
Orbital velocity in the perihelion 60.2 km / s
history
Explorer William R. Brooks
Date of discovery July 21, 1911
Older name 1911 V, 1911c
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . Please also note the note on comet articles .

C / 1911 O1 (Brooks) was a comet that could be seen with the naked eye in 1911 . Some consider it one of the " great comets ".

Discovery and observation

William Robert Brooks was one of the most successful comet searchers of his time. Since 1883 he had already visually discovered 20 comets, 17 of them as the sole discoverer. When he searched the sky with his telescope in Geneva (New York) on the morning of July 20, 1911 (local time) , he was supposed to discover his 21st and last comet, which would develop into the most impressive of all "his" comets.

After its discovery, the comet moved north and west in the sky and soon became visible in the evening sky . Towards the end of August, the comet could also be observed with the naked eye for the first time and in September it remained visible all night with a brightness of 4 mag as a circumpolar object.

At the end of September the comet is moving away from the earth again , but at the same time it was still approaching the sun , so that its brightness continued to increase rapidly and reached a value of 2 mag at dusk in mid-October , while its narrow, blue-white tail moved at 30 ° stretched across the sky and offered a sight little inferior to that of Halley's Comet a year earlier.

In mid-October the comet passed north of the Sun and could be seen in both the evening and morning skies for some time . At this time, together with Comet Brooks, Comet C / 1911 S3 (Beljawsky), discovered 2 months later, could be seen low in the western sky. At dusk on October 11, 1911, the two comets approached each other to a distance of about 20 °.

At the beginning of November, Comet Brooks appeared in the morning sky with 3 mag brightness and could no longer be seen with the naked eye from the end of the month. The last position was determined on February 28, 1912.

The comet reached a maximum brightness of 2 mag.

Orbit

For the comet, an elongated elliptical orbit could be determined from 619 observation data over a period of 221 days , which is inclined by around 34 ° to the ecliptic . At the point of the orbit closest to the sun ( perihelion ), which the comet traversed on October 28, 1911, it was located at about 73.2 million km from the sun in the area between the orbits of Mercury and Venus . On September 18, it had already reached the closest approach to earth with 0.51 AU / 77.0 million km . On October 21st, the comet had passed Venus 59.0 million km away .

The comet moves in an extremely elongated elliptical orbit around the sun. According to the orbital elements afflicted with a certain uncertainty, its orbit before its passage through the inner solar system in 1911 still had an eccentricity of about 0.9969 and a semi-major axis of about 159 AU, so that its orbital period was about 2000 years. It could have appeared in antiquity around the year –100. Due to the gravitational pull of the planets, especially by passing Uranus on February 27, 1906 at a distance of about 4½ AU and at Jupiter on August 22, 1911 at almost 6 AU distance, but especially by passing Jupiter again on July 30, 1912 at a distance of 3 ⅓ AU, its orbital eccentricity remained almost unchanged, but its semi-major axis was shortened to about 154 AU, so that its orbital period was reduced to about 1900 years. When it reaches the point of its orbit furthest from the sun ( aphelion ) around the year 2860 , it will be around 45.9 billion km from the sun, almost 307 times as far as the earth and 10 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 3800.

See also

Web links

Individual evidence

  1. ^ R. Stoyan: Atlas of Great Comets . Cambridge University Press, Cambridge 2015, ISBN 978-1-107-09349-2 , p. 36.
  2. ^ R. Wielen, Thomas Hockey (Ed.): Bibliographical Encyclopedia of Astronomers . Springer, New York 2007, ISBN 978-0-387-31022-0 , p. 172.
  3. ^ John E. Bortle: International Comet Quarterly - The Bright-Comet Chronicles. Retrieved September 17, 2015 .
  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 / 1911 O1 (Brooks) in the Small-Body Database of the Jet Propulsion Laboratory (English).
  6. ^ BG Marsden, Z. Sekanina, E. Everhart: New Osculating Orbits for 110 Comets and Analysis of Original Orbits for 200 Comets. In: The Astronomical Journal. Vol. 83, no. 1, 1978, pp. 64-71 doi: 10.1086 / 112177 .
  7. ↑ SOLEX 11.0 A. Vitagliano. Archived from the original on September 18, 2015 ; accessed on May 2, 2014 .