Great comet

The Great Comet of 1843 (Great March Comet)

A large comet is a comet that appears extraordinarily bright and spectacular, especially through a tail that is clearly visible to the naked eye .

definition

There is no officially recognized definition of “large comet”. As a rule of thumb , however, it is a phenomenon that occurs by chance even to an inexperienced observer of the night sky . To do this, the comet must achieve an apparent brightness that equals the 22 brightest stars of the first magnitude (this corresponds to a value of 1.5 mag).

While most comets can only be observed with the help of telescopes , some develop a brightness that allows them to become conspicuous even when open-eyed . The reasons for this are the comet's close proximity to the sun or earth and usually an unusually large or active cometary nucleus . Most large comets are therefore long-period comets, or comets that are entering the inner solar system for the first time . Short-period comets, which lose material every time they approach the sun, are seldom a noticeable phenomenon even near the earth. The only exception is Halley's Comet , the often spectacular appearances of which have been recorded several times as the “Great Comet”.

Selection of large comets

The following selection and the information on brightness and tail lengths as well as the duration of visibility with the naked eye are essentially based on the lists by Donald K. Yeomans and (from the 19th century) by John E. Bortle with additions from individual cometary articles.

Since 240 BC Comet 1P / Halley , which can be observed regularly every 74 to 79 years, is not included.

Before the calculation of time

Great comet from 373 BC: The comet was visible at the turn of the year −373 to −372 and the Greek historian Ephoros reports that the comet had split into two pieces.
C / -43 K1 (Comet Caesar) (44 BC): The daylight comet was visible from May to July for at least 72 days. While it was observed in China as early as May / June, its visibility in Italy was limited by a strong Etna eruption until July. According to Ramsey & Licht (1997), −3.3 mag and a maximum of −4.0 mag are recorded during a last flare-up (July 23 to 25).

1st millennium

Great comet of 178: Chinese observers report a tail length of over 70 ° and were able to observe the comet for about 80 days.
Great comet of 191: Chinese observers report a comet's tail over 90 ° in length.
C / 240 V1: The comet reached about 1 to 2 mag in 39 days of visibility with the naked eye.
C / 390 Q1: Chinese observers report a tail length greater than 70 °. The maximum brightness reached −1 mag with visibility for 26 days.
C / 400 F1: The comet reached a maximum of 0 mag with 30 days of visibility.
C / 442 V1: The comet reached about 1 to 2 mag with 100 days of visibility.
C / 565 O1: The comet reached 0 to 1 mag with 100 days of visibility.
C / 568 O1: The comet reached 0 mag with 106 days of visibility.
C / 770 K1: The comet reached about 1 to 2 mag with 62 days of visibility.
X / 838 V1: This comet was visible for 49 days.
X / 891 J1: Chinese observers report a tail length greater than 70 ° with 62 days of visibility.
C / 905 K1: Chinese observers report a tail length greater than 70 °. The maximum brightness reached 0 mag with 26 days of visibility.

12th Century

X / 1106 C1: The great comet from 1106 was visible for 40 days, passed very close to the Sun and could perhaps be the original body of the comets of 1882 and 1965 or that of 1843.
C / 1132 T1: The comet reached −1 mag and was visible for 24 days.

13th Century

C / 1240 B1: The comet reached 0 mag and was visible for 64 days.
C / 1264 N1: On July 26, 1264, Chinese observers reported a tail with a length of 100 °. The maximum brightness reached 0 mag with 85 days of visibility.

14th Century

Apart from two appearances of Halley's Comet, there are no reports of large comets from this period.

15th century

C / 1402 D1: In mid-March 1402 the comet was conjunct the sun and there are reports that it could be observed in the daytime sky for 8 days . The brightness reached a maximum of −3 mag with 70 days of visibility.
C / 1468 S1: The comet reached about 1 to 2 mag with 56 days of visibility.
C / 1471 Y1: The comet reached −3 mag with 59 days of visibility.

16th Century

The Great Comet of 1577

C / 1532 R1: The comet reached −1 mag in 120 days of visibility with the naked eye.
C / 1533 M1: The comet was only discovered after its proximity to the Sun and reached 0 mag. He was observed for 83 days.
C / 1556 D1: The comet reached −2 mag with 72 days of visibility.
C / 1577 V1: The comet reached −3 mag with 87 days of visibility.

17th century

The Great Comet of 1664

C / 1618 W1: The comet reached around 0 to 1 mag with 67 days of visibility to the naked eye.
C / 1664 W1: The comet reached −1 mag with 90 days of visibility.
C / 1665 F1: The comet was last observed on April 20, shortly before the sun conjunction. The maximum brightness reached −1 mag with visibility for at least 24 days.
C / 1668 E1: The comet reached about 1 to 2 mag with 27 days of visibility.
C / 1680 V1: This comet, which was first spotted with the help of a telescope , reached about 1 to 2 mag with 88 days of visibility. A leaflet illustrated with the picture of the 90 ° long tail on the “wonderful incomparable comet” describes it as God's warning to bring about “great penance and conversion” and contains precise observations with almost correct distance and size information.
C / 1686 R1: The comet reached about 1 to 2 mag with 34 days of visibility.

18th century

The tail rays of the comet of 1743 (Klinkenberg)

C / 1743 X1: On February 27, 1744, the tail star, also known as Comet Klinkenberg or Chéseaux , could be seen even during the day, only 12 ° from the sun. Its brightness should have reached about −3 mag with 110 days of free-eye visibility.
C / 1769 P1 (Messier): The comet's tail is said to have been over 90 degrees long when it came closest to Earth. It achieved a brightness of 0 mag with 94 days of visibility.

19th century

C / 1807 R1 (Great Comet): The comet reached about 1 to 2 mag with 90 days of visibility.
C / 1811 F1 (Great Comet): The comet, also known as Flaugergues , could be seen freely for more than 8 months. In October 1811 it reached its greatest apparent magnitude of about 0 mag.
C / 1819 N1 (Great Comet): The comet, also known as Tralles , reached a brightness of 1 mag and was visible to the naked eye for about a month.
C / 1825 N1 (Pons): The comet reached a brightness of 2 to 3 mag and was initially visible to the naked eye in the northern hemisphere , then in the southern hemisphere for almost 4 months.
C / 1830 F1 (Great Comet): The comet reached a brightness of 2 mag and was initially visible to the naked eye in the southern hemisphere, then in the northern hemisphere for a total of 2 ½ months.
C / 1831 A1 (Great Comet): The comet must have been a spectacular sight in the southern hemisphere before it passed the sun, but it apparently went unnoticed there. It was discovered late and could only be observed from the northern hemisphere for a few weeks. It reached a brightness of 2 mag.
C / 1843 D1 (Great March Comet): In the perihelion , which the comet passed through on February 27, 1843, it could only be seen 1 ° next to the sun in the daytime sky . Its brightness was greater than −3 mag with 48 days of visibility. Because of its long tail, it is considered the most beautiful of the century and is counted among the daylight comets in literature.
C / 1847 C1 (Hind): Comet Hind was the first comet to be observed only telescopically in the daytime sky . It reached a brightness of −4 mag and was visible to the naked eye for about 1 month.
C / 1853 L1 (clinker feet): The comet Klinkerfues also achieved such a brightness that it could be observed telescopically in the daytime sky . It reached a brightness of −1 mag and was visible to the naked eye for 2 months.
C / 1854 F1 (Great Comet): The comet reached a magnitude of 0 to 1 mag and was visible to the naked eye for about 3 weeks.

The Great Comet of 1858 (Donati)

C / 1858 L1 (Donati): Comet Donati is said to have been one of the most beautiful comets that could ever be seen with the naked eye. In October 1858 it reached an apparent brightness of 0 to 1 mag with 80 days of visibility. It was also the first comet that could be photographed .
C / 1860 M1 (Great Comet): The comet reached a brightness of 1 to 2 mag and was visible to the naked eye for about 1½ months.

The Great Comet of 1861 (Tebbutt)

C / 1861 J1 (Great Comet): The comet, also called Tebbutt after its discoverer, came on June 30, 1861 to within 0.13 AU / 19 million km of the earth; it must have slipped through the end of his tail, which was 120 degrees long when it came closest to the earth and - spread out wide - covered half of the sky. The comet was so bright that it could be seen before sunset and objects cast shadows in its light at night. It reached a brightness of about −3 mag with 90 days of visibility and was observed telescopically until April 1862. It takes the top spot among the top 10 comets (4th web link). It is probably identical to C / 1500 H1 , which was observed in China in 1500 but was less close to Earth at the time.
C / 1865 B1 (Great Southern Comet): The comet could only be seen in the southern hemisphere. He reached 1 mag with 36 days of visibility.
C / 1874 H1 (Coggia): The comet reached 0 to 1 mag with 50 days of visibility.
C / 1881 K1 (Great Comet): The comet reached a brightness of 1 mag and was visible to the naked eye for about 4 months.
C / 1882 F1 (Wells): The comet reached a brightness of 0 mag and could be observed telescopically in the daytime sky.
C / 1882 R1 (Great September Comet): The comet, a sun scraper of the Kreutz group , approached the sun to within 0.008 AU (1.2 million km) on September 17, 1882 and broke into at least four parts due to the solar tidal forces . With a brightness of more than −3 mag, the comet was bright enough to be visible next to the sun during the day. It was visible for over 4 ½ months.

20th century

The Great Comet of 1901

C / 1901 G1 (Great Comet): The comet reached 1 mag in 1901 with 38 days of visibility.
C / 1910 A1 (Great January Comet): Appearing just a few weeks before the expected return of Halley's Comet, this comet has often been mistaken for it. On January 17, 1910, it could easily be seen in the daytime sky, only 4.5 ° from the sun . It reached about Venus brightness (−4 mag) and was brighter than 1 to 2 mag for 20 days . It could be observed with telescopes until July.
Halley's Comet (1P / Halley): When it returned in 1910, the well-known Comet Halley attained an apparent magnitude of 0 to 1 mag, and its tail extended almost the entire sky with a maximum length of 150 °. On May 19, 1910, the earth even crossed the comet's tail.
C / 1911 O1 (Brooks): The comet could be seen together with the Comet Beljawsky at dusk in October 1911. It reached 2 mag brightness with about 3 months of visibility. The tail reached a length of 30 °.
C / 1911 S3 (Beljawsky): The comet could be seen in October 1911 together with the Comet Brooks at dusk. It reached 1 mag brightness with about 1 month of visibility. The tail reached a length of 15 °.
C / 1927 X1 (Skjellerup-Maristany): In December 1927 the comet could only be seen 5 ° from the sun in the daytime sky, it reached 1 mag brightness with 32 days of visibility. At the end of December the tail reached a length of almost 40 °.
C / 1941 B2 (de Kock-Paraskevopoulos): The comet could be seen especially from the southern hemisphere , it reached 2 mag brightness with about 1 month of visibility.
C / 1947 X1 (southern comet): The comet could only be seen in the day sky from the southern hemisphere, it reached −1 mag brightness with about 3 weeks of visibility. The comet broke in two a few days before it reached its closest point to the Sun.
C / 1948 V1 (eclipse comet): The comet was discovered during a total solar eclipse in Kenya . It reached −2 mag brightness with not quite 2 months of visibility.
C / 1956 R1 (Arend-Roland): The comet reached a maximum brightness of about 0 mag in April 1956. The tail turned away from the sun reached a length of 25 °. In addition, the comet showed a counter- tail with a length of 15 ° pointing to the sun .
C / 1957 P1 (Mrkos): When it was discovered, the comet was already extremely bright and had a tail. It reached 1 mag brightness with about 6 weeks of visibility.
C / 1961 O1 (Wilson-Hubbard): The comet was discovered from airplanes. It developed a 25 ° long tail, but its brightness remained low at 3 mag for a large comet and it was only visible for about 2 weeks.
C / 1962 C1 (Seki-Lines): This comet has an interesting history of discovery. It reached a maximum brightness of −2.5 mag with just under 2 months of visibility.
C / 1965 S1 (Ikeya-Seki): On October 21, 1965, this sun streak from the Kreutz group approached the sun to just 0.0078 AU / 1.16 million km. The comet's nucleus broke into two parts. With an apparent magnitude of −10 mag and 30 days of visibility, the comet was the brightest comet of the 20th century. After flying past the sun, the comet could be seen at dawn with a tail of up to 45 ° in length.
C / 1969 Y1 (Bennett): The comet reached around 0 to 1 mag with 80 days of visibility. In mid-March 1969 a tail 10 ° long had developed.
C / 1970 K1 (White-Ortiz-Bolelli): Another sun streak that could only be seen from the southern hemisphere. The comet reached about 0.5 mag brightness with 2 weeks of visibility.

The Great Comet of 1997 (Hale-Bopp)

C / 1975 V1 (West): The comet was photographed at the European Southern Observatory in August 1975 and on February 25, 1976 it approached the Sun to just 0.196 AU / 29 million km. Its core broke into four parts as a result of the solar tidal forces . The comet's head achieved a brightness of −1 mag with 55 days of visibility and a tail length of up to 30 °.
C / 1996 B2 (Hyakutake): The comet approached Earth on March 24, 1996 to within 0.109 AU / 16 million km. It achieved an apparent brightness of about 1 to 2 mag with 30 days of visibility and a tail length of 75 °.
C / 1995 O1 (Hale-Bopp)

21st century

The Great Comet of 2006 (McNaught)

C / 2006 P1 (McNaught): In the days around the perihelion passage on January 12, 2007, the comet could be seen a few degrees next to the sun in the daytime sky . The brightness reached −6 mag after 25 days of free-eye visibility. A short time later it appeared in the southern sky with a huge and bright dust tail 30 ° long with many structures (striae), similar to Comet West from 1976.

literature

H. Mucke: Bright comets from −86 to +1950 . Astronomical Office, Vienna 1976

Web links

Astro Corner: Bright Comets
Great Comets in History (English)
Brightest comets seen since 1935 (English)
Comet Info: The top 10 comets.

Individual evidence

^ Donald K. Yeomans: NASA JPL Solar System Dynamics: Great Comets in History. Retrieved June 4, 2014 .
^ John E. Bortle: International Comet Quarterly - The Bright-Comet Chronicles. Retrieved July 16, 2015 .

[1] Donald K. Yeomans: NASA JPL Solar System Dynamics: Great Comets in History. Retrieved June 4, 2014 .

[2] John E. Bortle: International Comet Quarterly - The Bright-Comet Chronicles. Retrieved July 16, 2015 .