Movatterモバイル変換

[0]ホーム
URL:

Jump to content
WikipediaThe Free Encyclopedia
Search

Great comet

From Wikipedia, the free encyclopedia
Exceptionally bright comets
icon
This articleneeds additional citations forverification. Please helpimprove this article byadding citations to reliable sources. Unsourced material may be challenged and removed.
Find sources: "Great comet" – news ·newspapers ·books ·scholar ·JSTOR(January 2015) (Learn how and when to remove this message)
Comet McNaught as the Great Comet of 2007

Agreat comet is acomet that becomes exceptionally bright. There is no official definition; often the term is attached to comets such asHalley's Comet, which during certain appearances are bright enough to be noticed by casual observers who are not looking for them, and become well known outside the astronomical community. Typically, they are as bright or brighter than a second magnitude star and have tails that are 10 degrees or longer under dark skies.[1] Great comets appear at irregular, unpredictable intervals, on average about once perdecade. Although comets are officially named after their discoverers, great comets are sometimes also referred to by the year in which they appeared great, using the formulation "The Great Comet of ...", followed by the year. It can also be used as a generic name when a very bright comet is discovered by many observers simultaneously.[2]

Causes

[edit]
TheGreat Comet of 1680 overRotterdam as painted byLieve Verschuier

The vast majority of comets are never bright enough to be seen by the naked eye, and generally pass through the innerSolar System unseen by anyone exceptastronomers. However, occasionally a comet may brighten to naked eye visibility, and even more rarely it may become as bright as or brighter than the brightest stars. The requirements for this to occur are: a large and activenucleus, a close approach to theSun, and a close approach to theEarth. A comet fulfilling all three of these criteria will certainly be very bright. Sometimes, a comet failing on one criterion will still be bright. For example,Comet Hale–Bopp did not approach the Sun very closely, but had an exceptionally large and active nucleus. It was visible to the naked eye for several months and was very widely observed. Similarly,Comet Hyakutake was a relatively small comet, but appeared bright because it passed very close to the Earth.

Size and activity of the nucleus

[edit]

Cometary nuclei vary in size from a few hundreds of metres across or less to many kilometres across. When they approach the Sun, large amounts ofgas anddust are ejected by cometary nuclei, due to solar heating. A crucial factor in how bright a comet becomes is how large and how active its nucleus is. After many returns to the inner Solar System, cometary nuclei become depleted in volatile materials and thus are much less bright than comets which are making their first passage through the Solar System.

Comets
Comet Hale-Bopp

The sudden brightening ofComet Holmes in 2007 showed the importance of the activity of the nucleus in the comet's brightness. On October 23–24, 2007, the comet underwent a sudden outburst which caused it to brighten by factor of about half a million. It unexpectedly brightened from anapparent magnitude of about 17 to about 2.8 in a period of only 42 hours, making it visible to the naked eye. All these temporarily made comet 17P the largest (by radius) object in the Solar System although its nucleus is estimated to be only about 3.4 km in diameter.

Close perihelion approach

[edit]

The brightness of a simple reflective body varies with theinverse square of its distance from the Sun. That is, if an object's distance from the Sun is halved, its brightness is quadrupled. However, comets behave differently, due to their ejection of large amounts of volatile gas which then also reflect sunlight and may alsofluoresce. Their brightness varies roughly as the inverse cube of their distance from the Sun, meaning that if a comet's distance from the Sun is halved, it will become eight times as bright.

This means that the peak brightness of a comet depends significantly on its distance from the Sun. For most comets, theperihelion of their orbit lies outside the Earth's orbit. Any comet approaching the Sun to within 0.5 AU (75 million km) or less may have a chance of becoming a great comet.

Close approach to the Earth

[edit]

For a comet to become very bright, it also needs to pass close to the Earth.Halley's Comet, for example, is usually very bright when it passes through the inner Solar System every seventy-six years, but during its 1986apparition, its closest approach to Earth was almost the most distant possible. The comet became visible to the naked eye, but was unspectacular. On the other hand, the intrinsically small and faintComet Hyakutake (C/1996 B2) appeared very bright and spectacular due to its very close approach to Earth at its nearest during March 1996. Its passage near the Earth was one of the closest cometary approaches on record with a distance of 0.1 AU (15 million km; 39 LD).

List of great comets

[edit]
This list isincomplete; you can help byadding missing items.(December 2013)

Great comets of the past two millennia include the following below. This list includes multiple bright apparitions ofHalley's Comet since 86 BC:

Comet
DesignationNameImage Dimensions
(km)(a)		Total
magnitude (M1)(b)		Maximum
brightness		Perihelion
date		Remarks
X/-371Great Comet of 371 BC---371 BCAwinter comet reported byAristotle andEphorus[3]
P/-86 Q1Halley11 km5.52.06 August 87 BCRecorded by ancient Babylonians and Chinese[3]
C/-43 K1Caesar-–4.0–9.025 May 44 BCNamed afterJulius Caesar[4]
P/-11 Q1Halley11 km5.5–5.010 October 12 BCVisible to the naked eye for 5 months[3]
X/-4 G1Star of Bethlehem?---15 April 4 BC
P/66 B1Halley11 km5.5–7.026 January 66Possibly recorded onJosephus' book,The Jewish War
P/141 F1Halley11 km5.5–4.022 March 141
X/178 R1Great Comet of 178 AD---September 178[3]
X/191 T1Great Comet of 191 AD---20 October 191
P/218 H1Halley11 km5.5–4.017 May 218
C/240 V1Great Comet of 240 AD-4.5-30 November 240
X/254Great Comet of 254 AD---November–December 254Reported tail length to be several tens of degrees. Possible progenitor/apparition of322P/SOHO[5]
P/295 J1Halley11 km5.5–3.020 April 295
P/374 E1Halley11 km5.5–3.017 February 374Passed within 13.5 million km from Earth
C/390 Q1Great Comet of 390 AD-7.0–1.05 September 390
C/400 F1Great Comet of 400 AD-6.00.025 February 400
C/442 V1Great Comet of 442 AD-1.51.0–2.015 December 442
P/451 L1Halley11 km5.5–3.024 June 451Appeared before the defeat ofAttila the Hun at theBattle of Chalons
P/530 Q1Halley11 km5.5–3.026 September 530
C/565 O1Great Comet of 565 AD-1.50.015 July 565
C/568 O1Great Comet of 568 AD-5.00.025 September 568
P/607 H1Halley11 km5.5–4.013 March 607Passed within 13 million km from Earth[3]
X/676 P1Great Comet of 676 AD---August–September 676Reported tail length about 7 to 8 degrees. Possibly an earlier apparition ofC/1743 X1[6]
P/684 R1Halley11 km5.5–2.028 October 684[3]
P/760 K1Halley11 km5.5–2.022 May 760
C/770 K1Great Comet of 770 AD-3.21.0–2.05 June 770
P/837 F1Halley11 km5.5–3.028 February 837Closest known approach toEarth by Halley at 5 million km
C/905 K1Great Comet of 905 AD-4.50.026 April 905
P/912 J1Halley11 km5.5–2.09 July 912
P/989 N1Halley11 km5.5–1.09 September 989
P/1066 G1Halley
11 km5.5–4.023 March 1066Recorded in theBayeux tapestry
X/1106 C1Great Comet of 1106---1106Parent body of theKreutz sungrazers
C/1132 T1Great Comet of 1132-4.5–1.030 August 1132[3]
P/1145 G1Halley11 km5.5–2.021 April 1145Depicted on theEadwine Psalter[3]
P/1222 R1Halley11 km5.5–1.030 September 1222[3]
C/1240 B1Great Comet of 1240-2.50.021 January 1240[3]
C/1264 N1Great Comet of 1264
-3.0–4.00.020 July 1264[7]
P/1301 R1Halley
11 km5.5–1.024 October 1301Depicted on theAdoration of the Magi byGiotto di Bondone[3]
P/1378 S1Halley11 km5.5–1.09 November 1378[3]
C/1402 D1Great Comet of 1402
-0.0–1.0–3.021 March 1402Possibly an earlier apparition ofC/1743 X1[6][8]
P/1456 K1Halley11 km5.50.09 June 1456
C/1468 S1Great Comet of 1468-3.21.0–2.07 October 1468[3]
C/1471 Y1Great Comet of 1471
-2.0–3.01 March 1472Passed within 10 million km from Earth on January 1472[9]
P/1531 P1Halley
11 km5.5–1.025 August 1531[3]
C/1532 R1Great Comet of 1532-1.8–1.018 October 1532[3]
C/1533 M1Great Comet of 1533-3.00.015 June 1533[3]
C/1556 D1Great Comet of 1556
-3.0–2.022 April 1556[10]
C/1577 V1Tycho
-–1.8–3.027 October 1577
P/1607 S1Halley11 km5.50.027 October 1607Apparition seen byJohannes Kepler
C/1618 W1Great Comet of 1618
-4.60.0–1.06 December 1618
C/1664 W1Great Comet of 1664-2.4–1.04 December 1664[11]
C/1665 F1Great Comet of 1665-4.9–1.024 April 1665[3]
C/1668 E1Great Comet of 1668-6.01.0–2.028 February 1668[3]
C/1680 V1Kirch
-4.01.0–2.018 December 1680Also known asNewton's Comet
P/1682 Q1Halley
11 km5.5–1.015 September 1682Apparition seen by its namesake,Sir Edmond Halley
C/1686 R1Great Comet of 1686-5.01.0–2.016 September 1686[3]
C/1743 X1Klinkenberg–Chéseaux
-0.5–7.01 March 1744
P/1758 Y1Halley
11 km5.5–1.013 March 1759First successfully predicted return of Halley
C/1760 A1Great Comet of 1760-7.62.017 December 1759Passed within 10.2 million km from Earth
C/1769 P1Messier
-3.20.08 October 1769[3]
C/1807 R1Great Comet of 1807
-1.61.019 September 1807[3]
C/1811 F1Flaguergues
30–40 km-0.012 September 1811Visible to the naked eye for 8.55 months
C/1819 N1Tralles
-4.01.0–2.028 June 1819
C/1823 Y1de Bréauté–Pons
-6.50.09 December 1823
C/1831 A1Herapath-6.22.028 December 1830
P/1835 P1Halley
11 km5.50.016 November 1835
C/1843 D1Great Comet of 1843
15.8 km[12]4.9–3.027 February 1843Kreutz sungrazer
C/1844 Y1Great Comet of 1844-4.92.514 December 1844[13]
C/1845 L1Great Comet of 1845-4.0–2.06 June 1845
C/1854 F1Great Comet of 1854-7.02.024 March 1854[14]
C/1858 L1Donati
-3.30.0–1.030 September 1858First comet to be photographed
C/1861 J1Tebbutt
-3.90.012 June 1861
C/1865 B1Great Southern Comet of 1865
-3.81.014 January 1865[3]
C/1874 H1Coggia
-5.70.0–1.09 July 1874
C/1880 C1Great Southern Comet of 1880
2.2 km[12]7.1–8.93.028 January 1880Kreutz sungrazer
C/1881 K1Tebbutt
-4.11.016 June 1881
C/1882 R1Great Comet of 1882
61.4 km[12]0.7–17.017 September 1882Kreutz sungrazer, brightest comet ever recorded in history
C/1887 B1Thome
-6.3-11 January 1887Kreutz sungrazer
C/1901 G1Viscara
-9.0–1.524 April 1901
P/1909 R1Halley
11 km5.50.020 April 1910
C/1910 A1Great January Comet of 1910
-5.0–5.017 January 1910Appeared about four months before the 1910 apparition of Halley
C/1927 X1Skjellerup–Maristany
-5.2–4.018 December 1927
C/1947 X1Southern Comet of 1947
-6.0–5.02 December 1947[15]
C/1948 V1Eclipse Comet of 1948
-9.0–1.027 October 1948[15]
C/1956 R1Arend–Roland
-5.9–0.58 April 1957
C/1957 P1Mrkos
-4.171.01 August 1957
C/1962 C1Seki–Lines
--–1.51 April 1962[14]
C/1965 S1Ikeya–Seki
8.6 km[12]-–10.021 October 1965Kreutz sungrazer. Brightest comet of the 20th century
C/1969 Y1Bennett
7.52 km[16]4.60.020 March 1970[3]
C/1975 V1West
-4.4–3.026 February 1976[3]
C/1995 O1Hale–Bopp
60 km–1.3–1.81 April 1997Visible to the naked eye for 18 months
C/1996 B1Hyakutake
4.2 km7.40.01 May 1996Passed within 0.1 AU from Earth
C/2006 P1McNaught
25 km?5.4–5.512 January 2007Brightest comet of the 21st century so far
C/2011 W3Lovejoy
0.2–0.5 km15.3–4.016 December 2011Kreutz sungrazer
C/2020 F3NEOWISE
5 km7.50.5–1.03 July 2020[17][18][19][20][21]
C/2023 A3Tsuchinshan–ATLAS
11.8 km[22]6.5–4.927 September 2024[23][24]
C/2024 G3ATLAS
-7.6–3.813 January 2025[25]
Notes:
(a)Due to a non-spherical, irregular shape, a comet'sx,y, andz axes instead of an (average) diameter are often used to describe its dimensions.
(b)Total magnitude (M1) as defined inGary W. Kronk'sCometography: A Catalog of Comets book series
 ·  List ordered in ascending order by a comet's chronological apparition.

Notes

[edit]
  1. ^Seargent, David A. J. (2009).The greatest comets in history: broom stars and celestial scimitars. New York: Springer. p. vii.ISBN 978-0-387-09512-7.
  2. ^"IAU Comet-naming Guidelines".www.cbat.eps.harvard.edu. Retrieved8 December 2024.
  3. ^abcdefghijklmnopqrstuvwxD. K. Yeomans (April 2007)."Great Comets in History".ssd.jpl.nasa.gov.Jet Propulsion Laboratory. Retrieved2 February 2011.
  4. ^Ramsey, John T. & Licht, A. Lewis (1997),The Comet of 44 B.C. and Caesar's Funeral Games, Atlanta,ISBN 0-7885-0273-5{{citation}}: CS1 maint: location missing publisher (link).
  5. ^J. Cui; G. Li; Y. Zhao (2025). "322P/SOHO: The Counterpart of a Historical Comet in 254 CE?".Icarus.429 116382.Bibcode:2025Icar..42916382C.doi:10.1016/j.icarus.2024.116382.
  6. ^abM. Meyer; G. W. Kronk (2025)."The Great Comet C/1743 X1: Possible Identification in Historic Records of 1402, 1032, 676, and 336".Journal of Astronomical History and Heritage.28 (1):29–49.doi:10.3724/SP.J.140-2807.2025.01.02.
  7. ^The Living Age, Volume 58. Lithotyped by Cowles and Company, 17 Washington St., Boston. Press of Geo. C. Rand & Avery. 1858. p. 879.
  8. ^D. A. J. Seargent (2009).The Greatest Comets in History: Broom Stars and Celestial Scimitars. Springer Science + Business Media. p. 99.ISBN 978-0-387-09512-7.
  9. ^"Great Comet of 1471".Atlas of Great Comets. Cambridge University Press:49–50. 2015.doi:10.1017/CBO9781316145166.010.ISBN 978-1-107-09349-2.
  10. ^S. K. Vsekhsvyatsky (1958).Physical Characteristics of Comets. Moscow, USSR: Fizmatgiz. p. 102.
  11. ^"Great Comet of 1664".Atlas of Great Comets. Cambridge University Press:72–77. 2015.doi:10.1017/CBO9781316145166.016.ISBN 978-1-107-09349-2.
  12. ^abcdM. M. Knight; M. F. A'Hearn; D. A. Biesecker; G. Faury; et al. (2010)."Photometric Study of the Kreutz Comets Observed by SOHO from 1996 to 2005".The Astronomical Journal.139 (3):926–949.Bibcode:2010AJ....139..926K.doi:10.1088/0004-6256/139/3/926.
  13. ^Bond, G.P. (1850). "On the great comet of 1844–45".The Astronomical Journal.1: 97.Bibcode:1850AJ......1...97B.doi:10.1086/100067.
  14. ^abBortle, J.,"The Bright Comet Chronicles",harvard.edu, retrieved2008-11-18
  15. ^ab"Brightest comets seen since 1935".www.icq.eps.harvard.edu. Retrieved17 January 2024.
  16. ^A. H. Delsemme; D. A. Rud (1973). "Albedos and Cross-sections for the Nuclei of Comets 1969 IX, 1970 II and 19711".Astronomy & Astrophysics.28:1–6.Bibcode:1973A&A....28....1D.
  17. ^"Weekly Information about Bright Comets (2020 July 18: North)". Seiichi Yoshida. July 18, 2020.Archived from the original on July 19, 2020. RetrievedJuly 18, 2020.
  18. ^"Seiichi Yoshida's Diary of Comet Observations (2020)". Seiichi Yoshida. July 19, 2020.Archived from the original on July 20, 2020. RetrievedJuly 19, 2020.
  19. ^"Comet NEOWISE Updtae: Easy To See In The Evening! When And How To See Comet NEOWISE". Farmer's Almanac. July 18, 2020.Archived from the original on July 19, 2020. RetrievedJuly 19, 2020.
  20. ^"APOD: 2022 July 26 - Comet NEOWISE Rising over the Adriatic Sea". NASA. July 26, 2022. RetrievedOctober 17, 2024.
  21. ^"Great Comets: What Are They, And When Will the Next Comet Be Visible?". Star Walk. October 16, 2024. RetrievedOctober 17, 2024.
  22. ^B. Liu; M. T. Hui; X. Liu (2025)."Great comet C/2023 A3 (Tsuchinshan–ATLAS): Dust loss before perihelion"(PDF).Astronomy & Astrophysics.698: 95.arXiv:2507.12756.Bibcode:2025A&A...698A..95L.doi:10.1051/0004-6361/202554632.
  23. ^2024 October 21 - Comet Tsuchinshan-ATLAS over California. APOD Podcast. Event occurs at 6m00s – via YouTube.
  24. ^2024 November 11 - The Unusual Tails of Comet Tsuchinshan ATLAS. APOD Podcast. Event occurs at 0m19s – via YouTube.
  25. ^"Why Comet G3 (ATLAS) will be 'remembered as the Great Comet of 2025' (photos)". Space.com. January 27, 2025. RetrievedJanuary 27, 2025.

External links

[edit]
Features
Comet C/1996 B2 (Hyakutake)
Types
Related
Exploration
Latest
Culture and
speculation
Periodic
comets
Until 1985
(all)
After 1985
(notable)
Comet-like
asteroids
Lost
Recovered
Destroyed
Not found
Visited by
spacecraft
Near-Parabolic
comets
(notable)
Until 1990
After 1990
After 1910
(by name)
Minor planets
Asteroid
Distant minor planet
Comets
Other
Portals:
Retrieved from "https://en.wikipedia.org/w/index.php?title=Great_comet&oldid=1322191920"
Categories:
Hidden categories:
[8]ページ先頭
©2009-2025 Movatter.jp