by John E. Bortle (W. R. Brooks Observatory)
[Copyright 1998, John E. Bortle]
The following material provides brief accounts of all those comets seen between 1800 and 2000 that attained an observed maximum brightness of magnitude 0 or brighter, together with a few additional objects of special interest. In general, the material covers only the period of the comet's apparition during which the object was visible to the unaided eye. The celestial position, approximate magnitude, and physical appearance of each comet is chronicled. Since meaningful cometary photometry did not begin until shortly after 1900, magnitudes cited prior to that time must be considered rather approximate. In many cases, these have been derived from a combination of contemporary physical descriptions of the object, the orbital circumstances, and the compiler's 50 years of comet observing experience.
A primer explaining how comets are designated and named is available here; each comet's name is given parenthetically below after the formal designation, following the standard practice in all ICQ, CBAT, and MPC publications and webpages. Other abbreviations used below: T = time of perihelion passage; O.S. = old-style roman-numeral designation (pre-1995), based on perihelion passage.
COMET C/1995 O1 (HALE-BOPP). Visible with the unaided eye from July 1996 thru Oct. 1997, an all-time record; T = 1997 April 1. During July 1996, of sixth magnitude with traces of a tail. Moved westward across Ophiuchus in the evening sky. In mid-October, still fifth magnitude but with a 2- to 3-degree tail. By the end of December, when at solar conjunction, third to fourth magnitude, located in Aquila. Comet reported as magnitude 3.0 in the late-January morning sky with a short tail. During mid-February, second magnitude, telescopically displaying extraordinary structures near the nucleus. Two tails of 5 to 10 degrees in length. Comet moved to the northeast across Cygnus in late February (head 1st magnitude). During March, once again passed through solar conjunction but well north of the sun. Visible at both dawn and dusk for many days, the head being magnitude zero at mid-month. Nucleus could be followed telescopically until shortly after sunrise. Tails up to 20 degrees long. During early April visible as a striking evening object in northwestern sky crossing Cassiopeia and Perseus, magnitude -0.5 with a strongly curved dust tail at least 25 degrees in length. Toward the conclusion of April, of first magnitude when low in the west after twilight. A second-magnitude object in Taurus when nearing solar conjunction in mid-May. Only visible from the southern hemisphere in June, magnitude 2-3 with a short tail. The comet gradually faded as it moved to the southwest: magnitude 3 in July, fourth magnitude in August, fifth magnitude during September.
COMET C/1996 B2 (HYAKUTAKE). Observed with the unaided eye from early Mar. until early June; T = 1996 May 1. One of the grandest comets of the millennium! Encountered the earth under very likely the most favorable circumstances of any major comet since 1P/Halley in 837 AD! Initially a morning object situated far from the twilight regions in Libra, and moving almost due northward. By March 12, fourth magnitude with several degrees of tail. March 19, second magnitude. March 22-24, visible directly overhead in Bootes before dawn from mid-northern latitudes as an object of zero to first magnitude, displaying a 30-50 degree tail. On March 27, visible all night long with a head of magnitude zero and up to 2 degrees in diameter. Comet then situated immediately adjacent to the Pole Star and trailing an immense tail at least 70 degrees in length (some reports indicate up to 100 degrees!). In early April, observable in the northwestern evening sky, rapidly descended toward the twilight region, at magnitude 2 or 3. Following solar conjunction, visible briefly in May from the southern hemisphere as a small, faint, naked-eye object with a short tail.
COMET C/1975 V1 (WEST; O.S. 1976 VI). Followed with the naked eye from late Feb. until mid-Apr.; T = 1976 Feb. 25. One of the premier comets of the 20th Century -- a brilliant, multi-tailed object that was briefly visible during the daytime. Initially observable only from the Southern Hemisphere. During mid-February, of third magnitude. Just before perihelion passage, seen in the bright evening twilight from the northern hemisphere, magnitude -1 or -2. Between Feb. 25 and 28, when only 7 degrees from the sun, visible in the daytime sky with binoculars and even with the unaided eye, as an object of magnitude -3! Moved into the morning sky, where it displayed a huge tail consisting of five components, the longest of these being a deep reddish-colored dust tail 30-35 degrees in length. Nucleus observed to have broken into at least four fragments. In mid-March, second magnitude, main tail 10-15 degrees in length. At the end of the month, when situated in Delphinus, of fourth magnitude with the tail still over 5 degrees long. Dropped below naked-eye visibility by mid-April.
COMET C/1973 E1 (KOHOUTEK; O.S. 1973 XII). Period of naked-eye visibility spanned the end of Nov. until late Jan.; T = 1973 Dec. 28. Initially touted as the "Comet of the Century", it put on a disappointing display. From the very end of November, visible to the naked eye when situated to the south of the star Spica in the morning sky. Moved eastward. Rose to fourth magnitude before mid-December. Last spotted in the morning twilight of December 22 at third magnitude with a short tail. On several days around the time of perihelion, observed close to the sun by astronauts aboard Skylab; unexpectedly bright at magnitude perhaps -1 to -3. On January 1, 1974, seen by ground-based observers as a zeroth-magnitude object deep in the evening twilight. An abrupt drop in brightness followed. Comet was at third magnitude by January 5. A long, very faint tail spanning 15-20 degrees was reported near mid-month. Comet crossed Capricornus and Pisces, fading rapidly. About magnitude 4.5 on the 15th, and at the limit of visibility by the 30th.
COMET C/1970 K1 (WHITE-ORTIZ-BOLELLI; O.S. 1970 VI). Seen visually only from the 18th of May until the first week of June; T = 1970 May 14. A member of the Kreutz sungrazing group of comets. Observable strictly from the southern hemisphere. Visible only very briefly after sunset within the evening twilight. At discovery (May 18), of first magnitude. Over the course of the next week, the tail attained a length of 12-15 degrees. Comet faded at an extraordinary rate. Lost to the naked eye by May 31, and soon thereafter even to large instruments, as the comet once again moved to conjunction with the sun.
COMET C/1969 Y1 (BENNETT; O.S. 1970 II). Under observation with the naked eye from Feb. until mid-May; T = 1970 March 20. Brilliant, long-tailed comet that is considered by many to be one of the finest of the 20th century. Spotted in the far southern sky. During the first week of February, at fifth magnitude with a 1-degree tail. At the end of the month, mag +3.5 and tail 2 degrees. Of first magnitude during mid-March with a tail more than 10 degrees long. In late March, crossed Aquarius and Pegasus, visible from the northern hemisphere as a stunning morning object of magnitude zero at considerable elongation from the sun. Telescopically exhibited extraordinary spiraling jets of bright material being ejected from the nucleus. During the second week of April, first to second magnitude with two tails, the longest spanning over 20 degrees. At month's end, of third magnitude and circumpolar in Cassiopeia, visible all night. Early in May, the comet's head was of fourth magnitude, but tail was still 10-15 degrees in length. Lost to the naked eye around May 20.
COMET C/1965 S1 (IKEYA-SEKI; O.S. 1965 VIII). Observable with the unaided eye from early Oct. until mid-Nov.; T = 1965 October 21. The most brilliant comet of the 20th Century and a member of the Kreutz sungrazing group of comets. Detected initially on Sepember 18 in western Hydra. Moved rapidly to the east. At the opening of October, at sixth magnitude. By the 15th, at second magnitude, faint tail over 10 degrees long. For several days centered on perihelion passage (Oct. 21.18 UT), visible in the daytime very close to the sun as an object brighter than Venus. According to Japanese observers, magnitude exceeded -15 in the hours nearest the time of perihelion passage! Beginning the last week of October, an extraordinary, brilliant, dense tail was seen in the southeastern sky at dawn. The comet's head, then situated in Corvus, of second magnitude. Comet moved toward the southwest, crossing Crater and Hydra, its slightly curved tail growing rapidly to 25 degrees in length by the opening of November. The head was by then of fourth magnitude. Maximum tail length reached in late November at 35 degrees (photographically), the head having declined to about seventh magnitude.
COMET C/1962 C1 (SEKI-LINES; O.S. 1962 III). A naked-eye object from late Feb. through the end of Apr.; T = 1962 April 1. Extremely bright comet. Discovered on February 4 in Puppis, moving northwest. From the very end of February and in March, visible with the unaided eye, mainly from the southern hemisphere, as it crossed Eridanus and Cetus. Comet increased very rapidly in brightness, reaching fourth magnitude in mid-March. On the 27th, at magnitude 0 to -1; three days later, mag -1.5 or brighter. Comet passed only 4 million kilometers from the sun on April 1. Brightness should have reached mag -7; however, no daytime observations were ever reported. Comet was next seen on April 3 at magnitude -2.5 in very bright twilight. Dense, bright, slightly curving tail sighted in the next few days rising straight up out of the western twilight and eventually attaining a length of about 15 degrees. Comet traversed Pisces, Aries, and Taurus, its brightness declining quickly: at first magnitude on April 7, third magnitude on the 13th, fourth magnitude by the 21st. No longer visible to the unaided eye by April 29.
COMET C/1961 O1 (WILSON-HUBBARD; O.S. 1961 V). Visible to the unaided eye only between July 23 and the first days of Aug.; T = 1961 July 17. Very brief period of visibility. Detected in the morning twilight of July 23 near tau Geminorum as an object of second to third magnitude with a 15-degree tail. Comet located only 16 degress from the sun, moving to the northwest. On July 25, the tail was up to 25 degrees long photographically. For a few days, the comet was an impressive object with its long tail pointing straight up from the northeastern horizon. However, by July 29, the head had already fallen to fourth magnitude. On August 1, nearing the naked-eye limit, even though a tail up to 15 degrees long could still be detected. Comet faded very quickly, becoming a binocular object situated in Auriga during early August -- and could no longer be detected visually, even with moderate-sized telescopes, by mid-month.
COMET C/1957 P1 (MRKOS; O.S. 1957 V). Followed with the unaided eye from July 29 until the end of Sept.; T = 1957 August 1. Not discovered until just three days from perihelion. Spotted in the morning twilight of July 29, an object of first magnitude with a short tail, situated in Gemini not far from Pollux. Moved rapidly eastward, passing due north of the sun on August 5. For several days around this date, visible in both the morning and evening skies. During the second week of August, situated in the northwestern evening sky in the same relative position that comet C/1956 R1 (Arend-Roland) occupied four months earlier. Comet of first to second magnitude with two tails, the brighter one strikingly curved and 15 degrees long. Crossed southern Ursa Major and Coma Berenices. The comet faded very slowly. Of third magnitude late in August with a tail several degrees long. In mid-September, when in Virgo, still faintly visible with the unaided eye at the end of evening twilight as an object of fifth magnitude. Comet lost to the unaided eye in the last days of September.
COMET C/1956 R1 (AREND-ROLAND; O.S. 1957 III). Naked-eye visibility extended from mid-Mar. until mid-May; T = 1957 April 8. The first brilliant comet to be visible from the northern hemisphere since Halley's in 1910. Spotted nearly 6 months before perihelion passage as a tenth-magnitude object in Perseus. Moved toward the southwest. Observable only from the southern hemisphere in March and early April, rising steadily to first magnitude. During the latter half of April, seen from the Northern Hemisphere as an extraordinary object in the northwestern sky at the end of evening twilight. About April 15, the head was of zero magnitude, trailing a 25-30 degree tail. Between April 20 and May 3, the comet displayed a bright, sunward-pointing anti-tail up to 15 degrees long! At the conclusion of April, the brightness had fallen to third magnitude. The comet traversed Triangulum, Perseus, and entered Camelopardalus during this period. After the middle of May, when the comet had become a circumpolar object, it was finally lost to the unaided eye.
COMET C/1948 V1 (ECLIPSE COMET; O.S. 1948 XI). Period of naked-eye visibility extended from Nov. 1 until about Dec. 20; T = 1948 October 27. Visibility was limited to the southern hemisphere and low Northern latitudes. First spotted as a brilliant object situated about 2 degrees southwest of the sun during the total solar eclipse of November 1, at magnitude about -2. Re-discovered in the morning twilight of November 4 as an object of zeroth or first magnitude, displaying a 20-degree tail. Moved southwestward from Hydra to Puppis during November and December. In mid-November, at second magnitude with a tail described by some as up to 30 degrees in length. On November 26, still at magnitude 3.5, but tail considerably shorter. Of fifth magnitude during the first week of December and finally lost to the unaided eye around the 20th of the month.
COMET C/1947 X1 (SOUTHERN COMET; O.S. 1947 XII). First sighted on Dec. 7, faded rapidly and was lost to the naked eye by Dec. 25; T = 1947 December 2. Comet visible only from the southern hemisphere. Very-short-lived object. Discovered in the evening twilight of December 7 as an object of at least magnitude 0 and perhaps much brighter. Comet's head orange in color, and tail 20-30 degrees in length. Moved slowly almost due eastward across Sagittarius. On December 9, about first magnitude. A week later, the brightness had declined to third magnitude, and the tail had was no more than 5 degrees long. By December 20, the comet's head was between fourth to fifth magnitude, and its appendage was very short. The object dropped below the naked-eye limit about December 25.
COMET C/1941 B2 (DE KOCK-PARASKEVOPOULOS; O.S. 1941 IV). Followed with the unaided eye from Jan. 18 to the end of Feb.; T = 1941 January 27. Comet's visibility limited mainly to the southern hemisphere. At discovery (January 15), a sixth-magnitude object situated to the southwest of Antares and moving toward the southeast. Because of slow war-time communication, independently discovered by many persons over the next 10 days as a very obvious object in the morning sky. On January 25, of third magnitude with a 5-to 7-degree tail. At the close of January, passed well south of the sun. At that time, of second magnitude with a long tail, visible at both dawn and dusk. February 2, in the evening sky, described as second magnitude with a faint tail up to 20 degrees long. Thereafter moved toward the northeast, quickly losing brightness. On February 15, at fourth magnitude with a 5-degree tail. Lost to the unaided eye at the conclusion of February.
COMET C/1927 X1 (SKJELLERUP-MARISTANY; O.S. 1927 IX). Visible to the unaided eye from Nov. 27 until early Jan.; T = 1927 December 18. Comet visible almost exclusively from the southern hemisphere; very small perihelion distance. Already visible to the naked eye at discovery, situated in the southern constellation of Norma and moving rapidly northward to the sun. Reported as magnitude +3 on December 3, with a 3-degree tail. On December 18, visible in the daytime adjacent to the sun, magnitude -6! Following perihelion passage, lingered in the morning twilight for several weeks. Brightness had declined to third magnitude by December 21. Between December 29 and January 2, a huge but faint 40-degree tail was glimpsed in the pre-dawn sky, head still lost in twilight.
COMET C/1911 O1 (BROOKS; O.S. 1911 V). A naked-eye object from late Aug. until late Nov.; T = 1911 November 2. Discovered telescopically in the morning sky in late July. Moved north and westward, becoming an evening object. In mid-September, visible as a fourth-magnitude circumpolar object. During the first half of October, viewed in the northwestern evening sky as an object of second magnitude with a narrow, straight tail up to 30 degrees long, head distinctly bluish in color. At mid-month, visible together with bright, naked-eye Comet C/1911 S3 (Beljawsky) low in the western sky! Passed north of the sun on October 14, and for a time was visible at both dusk and dawn. In early November, visible low in the eastern sky at morning twilight as a third-magnitude object. Dropped below naked-eye visibility by month's end.
COMET C/1911 S3 (BELJAWSKY; O.S. 1911 IV). Followed with the unaided eye from the end of Sept. until the very end of Oct.; T = 1911 October 10. Discovered in the morning twilight of Sept. 29 as a bright object of second magnitude with a long tail. Moved eastward, passing north of the sun about Oct. 10 to become an evening object. For a few days, observable at both dawn and dusk. In mid-October, visible low in the western sky as a first-magnitude object with a golden-yellow head and a tail more than 15 degrees long. Between October 10 and 22, visible simultaneously with bright naked-eye Comet C/1911 O1 (Brooks) in the western sky during late evening twilight -- a unique event! Comet C/1911 S3 (Beljawsky) continued to move southeastward, crossing Libra late in the month and fading rapidly.
COMET 1P/1909 R1 (HALLEY; O.S. 1910 II). The period of naked-eye visibility extended from Feb. 11 (?) up to mid-July; T = 1910 April 20. Generally visible to the unaided eye from the beginning of April (solar conjunction had occurred in March). In April, when situated in Pisces, of magnitude 2-3 with a short tail. During May, rapidly approached the earth, brightening to magnitude zero, and the tail lengthened dramatically. Comet transited the sun on May 18. The tail at that time stretched up to 120 degrees (Taurus to Aquila!) across the morning sky. Beginning May 20, visible in the evening sky in Taurus. Moved swiftly eastward, crossing Gemini and Cancer in late May. The head was of first magnitude with a tail reportedly 30 degrees or more in length. In June, traversed Sextans and southern Leo, brightness dropping to third magnitude, and the tail steadily decreasing. Followed with the naked eye until mid-July.
COMET C/1910 A1 (DAYLIGHT COMET; O.S. 1910 I). Visible with the unaided eye from Jan. 12 until mid-Feb.; T = 1910 January 17. Spotted from the Southern Hemisphere in the morning twilight of January 12 as a brilliant object of magnitude -1. Moved quickly into conjunction with the sun. Between January 17 and 19, visible to the unaided eye in the daytime, its brightness peaking at magnitude -5. Beginning January 20, seen in the evening twilight from the northern hemisphere, looking like Venus but with a 10-degree tail. A week later, described as a magnificent sight in the western sky when situated in Aquarius. The comet's head was of first magnitude and the tail stretched 25 degrees. Moved north and eastward, declining in brightness. Between January 30 and February 3, the head having faded to third magnitude, the tail attained its greatest span of about 50 degrees. Thereafter, the object faded rapidly and was lost to the unaided eye before mid-February.
COMET C/1901 G1 (GREAT COMET; O.S. 1901 I). Followed with the naked eye from Apr. 12 until May 23; T = 1901 April 24. Also known as "Comet Viscara", this object was observed exclusively from the southern hemisphere. Discovered in the morning twilight as an object of second magnitude with a noticeable tail. Moved eastward passing south of the sun. On the day of perihelion passage, comet's head was reported as deep yellowish in color, trailing a 10-degree tail. Nucleus observed telescopically following sunrise, of magnitude -1 or -2. On May 3, a 30-degree straight tail and a curved tail up to 10 degrees long were observed, the comet's head being about magnitude 0. Comet traversed the boundary between Taurus and Eridanus, the twin tails pointing in the general direction of the star Sirius. Magnitude +2 on May 6. By May 15, the head had faded to about third magnitude, but the two tails had increased to 45 and 15 degrees in length. Thereafter faded rapidly. Not visible to the naked eye after May 23.
COMET C/1887 B1 (GREAT SOUTHERN COMET; O.S. 1887 I). Period of naked-eye visibility extended from Jan. 18 to the 30th; T = 1887 January 12. Referred to in some old texts as "The Headless Wonder"! Seen only from the Southern Hemisphere. Very brief period of visibility. Object a member of the Kreutz sungrazing group of comets. Detected first on January 18 in the evening twilight as a bright, narrow ribbon of light 40 degrees long, terminating at the southwestern horizon. When situated further from the sun in the following days, seen to have no discernible head or coma! On January 24, the "tail" was more than 50 degrees long, but much fainter and of uniform brightness over its entire length. January 28, tail extremely faint, but still about 30 degrees long. Comet not detected on February 1.
COMET C/1882 R1 (GREAT SEPTEMBER COMET; O.S. 1882 II). Followed with the unaided eye from Sept. until mid-Feb. 1883; T = 1882 September 17. Brightest, most extraordinary comet in over 1,000 years. A member of the Kreutz sungazing group of comets. Spotted on the morning of September 1, and from the 7th or 8th was observed throughout the world in western Hydra with a second- to third-magnitude head and a short tail. Moved rapidly due east to the sun. Brightness exceeded Jupiter (mag -2) on September 13; tail 12 degrees long. On September 17, at perihelion, easily visible to the unaided eye at noon, less than 1 degree from the sun, magnitude perhaps -17, with a tail up to 3 degrees long! Following perihelion passage, brighter than before, probably as a result of the nucleus disrupting (six components reported). Thereafter, followed in the daytime sky for over a week. Reappeared in the morning sky at the end of September, moving to the southwest. At the end of September, at magnitude zero with an incredibly brilliant 25-degree tail. In the first half of October, a dozen or more "satellite" comets reported to the southwest of the main comet! In the end of October, at second magnitude with a 30-degree tail. Early in December, still an imposing object of third magnitude with a considerable tail, visible all night long in the southern part of the sky. Even as late as mid-January 1883, when the comet was situated to the southwest of Sirius, the head was about fourth magnitude with a 15-degree tail. Finally dropped below naked-eye visibility in mid-February.
COMET C/1882 F1 (WELLS; O.S. 1882 I). Under naked-eye observation from late May until early July; T = 1882 June 11. Toward the end of May, visible to the unaided eye as a fourth-magnitude object in Camelopardalis and observable at both morning and evening twilight. Crossed Perseus in the first week of June, brightening from third to zeroth magnitude, tail more than 5 degrees long. Entered morning twilight about June 7. On June 10, visible telescopically in the daytime as a brilliant, star-like object immediately adjacent to the sun and perhaps as bright as magnitude -6. Temporarily became a southern-hemisphere object following perihelion. On June 17, a long tail was reported extending out of the evening twilight, its tip being 40-45 degrees from the position of the comet's head. However, this long tail seems to have been short-lived. The comet subsequently moved eastward, fading from second to sixth magnitude as it crossed Gemini, Cancer, and Leo in late June and early July.
COMET C/1881 K1 (GREAT COMET; O.S. 1881 III). Visible to the naked eye from late May until the end of July; T = 1881 June 16. Also known as "Comet Tebbutt". Discovered in the far southern sky on May 22, moving due northward along the fifth-hour meridian of right ascension. Until mid-June, visible only from the southern hemisphere. Comet brightened from fifth to first magnitude, tail up to 10 degrees long. On June 19, passed almost directly between the earth and sun. During the second half of June, visible to observers in the northern hemisphere as it crossed Taurus, Auriga, and Camelopardalis. June 25, comet of first magnitude with a 20-degree tail. Reported as first to second magnitude with a 14-degree tail on June 27 -- at which time the comet was a circumpolar object for Europe, etc. In the middle of July, of third magnitude, the tail's length rapidly decreasing. Still faintly visible to the unaided eye at the very end of July, when approaching the north celestial pole.
COMET C/1880 C1 (GREAT SOUTHERN COMET; O.S. 1880 I). Seen with the naked eye from Jan. 31 until Feb. 15, T = 1880 January 28. A member of the Kreutz sungrazing group of comets. Visibility limited to the Southern Hemisphere. First detected on the evening of January 31 as a bright beam of light extending from below the southwestern horizon. Comet moved eastward away from the sun. On February 2, the tail was described as 40 degrees long, the head of third magnitude. On the 5th, the tail was more than 50 degrees in length and uniformly bright. The comet's head rapidly faded, but the tail remained very long. On February 14, with the comet's head near the naked-eye limit, tail still 35 degrees long. However, the comet faded completely from view after February 19.
COMET C/1874 H1 (COGGIA; O.S. 1874 III). Visible to the naked eye from the beginning of June until the end of Aug.; T = 1874 July 9. For many weeks following discovery almost stationary in Camelopardalis. In mid-June, about fifth magnitude. By the end of the month, third magnitude. In July, began to move rapidly southward. At that time, the comet was in conjunction with the sun but far north of it in Lynx and visible all night. On July 6th, of second magnitude with a 10-degree tail. On the 13th, brighter than nearby Capella and displaying a 20- to 30-degree tail. By July 18, comet's head was lost in twilight, but a 48-degree tail observed. Two nights later, tail up to 63 degrees long. Comet passed between the earth and sun on July 20. Thereafter, visible only from the Southern Hemisphere. Passed near Procyon on July 23 -- head similar in magnitude. At the end of July, a second-magnitude object to the southeast of Sirius. In mid-August, situated not far from Canopus and of fourth or fifth magnitude.
COMET C/1861 N1 (TEBBUTT; O.S. 1861 II). A naked-eye object from discovery until mid-Aug.; T = 1861 June 12. Extraordinary display created by comet's close encounter with the earth. Spotted in the southern hemisphere on May 13 at fourth magnitude. Moved north very slowly across Eridanus. On June 8, of second magnitude. At mid-month, first magnitude. Tail already 40 degrees long. Thereafter, motion increased dramatically. On June 24, when near Rigel, zeroth magnitude. In conjunction with the sun on June 29. The earth passed through the comet's tail! In the northern hemisphere, appeared suddenly in Auriga at dawn -- immense, brilliant object. Descriptions suggest the head's magnitude was at least -1 or -2, and possibly briefly as bright as -4 or -5. Tail seen to stretch from Auriga to Ophiuchus -- 120 degrees! Comet became circumpolar on July 1. The next night, the head was zeroth magnitude, tail 97 degrees long. On July 8, when near the Big Dipper, of first magnitude with a tail up to 60 degrees long. Thereafter rapidly declined in brightness. Of second to third magnitude at mid-month, fourth at the end. Lost to the unaided eye in mid-August.
COMET C/1860 M1 (GREAT COMET; O.S. 1860 III). Followed with the unaided eye from June 18 until about the end of July; T = 1860 June 16. Discovered in the evening twilight of June 18 on the northwestern horizon, situated in Auriga. Comet of first magnitude with a tail up to 20 degrees long. At the opening of July, located in Lynx and of first or second magnitude, displaying a 15-degree appendage. Between July 6 and 12, crossed western Leo, passing near Regulus on the night of the 10th. Brightness then about third magnitude, with the tail rapidly decreasing in length. After mid-month, the comet's motion carried it across Crater and Corvus. Comet soon became a southern-hemisphere object, from where it was independently discovered with the naked eye. Thereafter, it quickly dropped below the threshold of the unaided eye.
COMET C/1858 L1 (DONATI; O.S. 1858 VI). Followed with the unaided eyed from mid-Aug. until the end of Nov.; T = 1858 September 30. Comet occupied a unique position in the heavens during much of its apparition. Discovered in the evening sky. From the beginning of August until the first week in October, in conjunction with (but located well north of) the sun. From August 15 onward, seen with the naked eye both after sunset and before sunrise, growing steadily brighter. In the opening of September, at third magnitude with a short tail. At mid-month, second magnitude, situated in the feet of Ursa Major with a 4-degree tail. By month's end, zeroth to first magnitude, tail up to 20 degrees long. The first half of October, while crossing Bootes and Serpens, very spectacular, with a head brighter than Arcturus and a huge, gently curving tail up to 60 degrees long. Comet detected telescopically in daylight. Moved rapidly southeastward, dropping below the horizon about mid-month. Followed in the southern hemisphere with the unaided eye until the end of November.
COMET C/1854 F1 (GREAT COMET; O.S. 1854 II). Period of naked-eye visibility extended from Mar. 23 until mid-Apr.; T = 1854 March 24. Relatively short-lived object. Discovered in the morning twilight of March 23 as an object of zeroth to first magnitude. Located in southern Pegasus. Moved to conjunction with the sun, passing well north of it on March 27, and entering the evening sky. At the very end of the month, situated in Pisces, being of first magnitude with a 5-degree tail. Traversed Aries during the first week of April, fading rapidly from second to about fourth magnitude, but tail still spanned up to 5 degrees. In mid-April, while crossing southern Taurus, near the limit of naked-eye visibility with a 1-degree tail.
COMET C/1853 L1 (KLINKERFUES; O.S. 1853 III). Visible to the unaided eye from early Aug. through early Oct.; T = 1853 September 2. During early August, situated in southernmost Ursa Major in the evening sky, at magnitude about 5. Comet moved slowly to the southeast, gradually entering the twilight. Already on August 13, of about third or fourth magnitude. By the 19th, reported as bright as second magnitude with a tail several degrees long. On the 26th, about magnitude 0 with a 10-degree tail while located within the evening twilight in eastern Leo. During the last days of August and the first week of September, visible telescopically in daylight, head's magnitude at least -1. Comet moved south of the sun to become a morning object for the southern hemisphere. In mid-September, when situated in Hydra, of second magnitude with a 5-degree tail. Comet faded rapidly and was lost to the unaided eye before mid-Oct.
COMET C/1847 C1 (HIND; O.S. 1847 I). Span of naked-eye visibility was from late Feb. until late Mar.; T = 1847 March 30. Comet distinctive for its telescopic daytime visibility rather than its display in a dark sky. Reportedly first detected with the unaided eye on February 19. At that time, visible all night as a circumpolar object in Cepheus. Moved steadily toward the southeast, crossing Cassiopeia during first week of March. At mid-month, when situated in the evening sky in Andromeda, of third or fourth magnitude with a tail over 3 degrees long. Last pre-perihelion observation made on March 24 in bright evening twilight at magnitude +1 or +2. On March 30, the comet was visible telescopically at noon, magnitude perhaps as bright as -4. Following perihelion, the comet remained in conjunction with the sun until it had faded below naked-eye visibility.
COMET C/1843 D1 (GREAT MARCH COMET; O.S. 1843 I). Followed with the unaided eye from Feb. 5 until Apr. 3; T = 1843 February 27. Object a member of the Kreutz sungrazing group of comets. Spotted on February 5, low in the southwestern sky following evening twilight, of magnitude perhaps 3 or 4. Moved rapidly to conjunction with the sun. On the 28th, visible throughout the day in both Europe and America as a brilliant object immediately adjacent to the sun; incredibly bright (mag -6 to -8) and displaying a 3-degree tail against the blue sky! For the next two weeks, visible mainly from the southern hemisphere. In the first week of March, of magnitude 1 or 2 with a 35- to 40-degree tail. About March 13, tail 45 degrees long, head of third magnitude. By mid-month, comet once again easily visible from northern latitudes, its head situated near the Cetus/Eridanus border, the tail extending to the south of the star Rigel. Proceeded steadily eastward. On March 20, the head had faded to about magnitude 4, but the long, straight tail could be traced about 65 degrees. At the end of March, tail still nearly 40 degrees long. Comet's head last detected with the naked eye on April 3, but a good portion of the tail was still apparent.
COMET 1P/1835 P1 (HALLEY; O.S. 1835 III). Viewed with the unaided eye from Sept. 23 until Feb. 18; T = 1835 November 16. First detected without optical aid on September 23 when situated in the morning sky in eastern Auriga. Moved swiftly to the northeast. By October 5, already of third magnitude. Beginning October 8, visible all night as an object of magnitude 1-2 in Ursa Major. Passed through solar conjunction far north of the sun, entering the evening sky. On October 14, located in northernmost Bootes, of first magnitude with a 20-degree tail. By October 20, situated in Ophiuchus, at magnitude 1-2 and still with an impressive tail. In the first half of November, about second magnitude, drifting slowly to the southwest and then entering the evening twilight. Following solar conjunction, reported as about second magnitude at the very end of January 1836 -- about 30-50 times brighter than expected! Comet situated a little southwest of Antares. Throughout the first half of February, seen as a steadily fading naked-eye object.
COMET C/1831 A1 (GREAT COMET OF 1831; O.S. 1830 II). Period of naked-eye visibility spanned the month of January 1831; T = 1830 December 28. Comet not discovered until late, in what must have been a very spectacular apparition. In early December of 1830, should have been a bright morning object for the southern hemisphere. Crossed over into the evening sky at mid-month while approaching the sun. During the final week of the year, the comet should have been of great brilliance, perhaps exceeding Venus, when an evening object near the sun. Moved westward, returning to the morning sky. Comet finally discovered on January 7, 1831, at dawn in Serpens, at magnitude about +2 with an appendage measuring a couple of degrees in length. Quickly waned, and at mid-month was already about fourth magnitude with a 3-degree tail. Lost to the unaided eye before month's end.
COMET C/1830 F1 (GREAT COMET OF 1830; O.S. 1830 I). Followed with the unaided eye from mid-Mar. until about mid-May; T = 1830 April 9. Comet notable for its extended period at considerable brightness. Discovered near the south celestial pole on March 16, at already about third magnitude with a 5-degree tail. Moved due northward, parallelling the 21st meridian of right ascension. On the first of April, situated in Microscopium in the morning sky, at magnitude about +2 and with a short tail. During mid-April, situated at a considerable elongation from the sun when crossing Aquarius. Observed throughout the world as an object of second or third magnitude with a tail several degrees long. Visible as a fourth-magnitude object in western Pegasus at the commencement of May, still with a degree or two of tail. Comet finally dropped below the naked-eye threshold about mid-month.
COMET C/1825 N1 (PONS; O.S. 1825 IV). Visible with the unaided eye from late Aug. until the end of Dec.; T = 1825 December 11. An intrinsically very bright comet with an exceptionally long period of naked-eye visibility. Seen with the naked eye for the first time in late August as a fifth-magnitude object in the head of Taurus in the morning sky. Comet moved to the southwest. In mid-September, about fourth magnitude, tail up to 8 degrees long. In mid-October, visible most of the night while in Sculptor, at magnitude 2-3 with a tail spanning 14 degrees. Soon thereafter, situated too far south to be well seen from Europe and America. In early November, apparently an object of magnitude 2-3 in Indus in the southern evening sky. Lost in the evening twilight toward the end of December, when probably still at magnitude 3-4 and located in Sagittarius to the southeast of the sun.
COMET C/1819 N1 (GREAT COMET; O.S. 1819 II). Period of naked-eye visibility spanned the month of July; T = 1819 June 28. Also known as "Comet Tralles". Spotted on July first in the evening sky, a little to the north of the sun, the head being of about zeroth magnitude. Comet crossed eastern Auriga and was visible at both dusk and dawn for several weeks. At the end of the first week of July, at first magnitude with a 7- to 8-degree tail. Comet faded rapidly as it moved toward the northeast, almost pacing the sun. At mid-month, situated in Lynx, an object of third magnitude with a short tail. In the last few days of July, the comet's brightness rapidly approached the naked-eye threshold.
COMET C/1811 F1 (GREAT COMET; O.S. 1811 I). Followed without optical aid from Apr. 1811 until Jan. of 1812; T = 1811 September 12. Also known as "Comet Flaugergues". During April, faintly visible to the unaided eye low in the evening sky in Puppis. Brightened to roughly magnitude 5 before entering the twilight. Not seen again until the third week of August, when still in conjunction with the sun but well north of it in Leo Minor. Visible at both dusk and dawn as an object of magnitude perhaps 2-3. Moved steadily to the northeast. In mid-September, of magnitude 1-2; tail a dozen degrees long. In the beginning of October, visible throughout the night from mid-northern latitudes as a spectacular object situated below the handle of the Big Dipper. Comet's head about first magnitude with a tail spanning up to 25 degrees. Later in October, traversed Bootes and Hercules as an evening object, at magnitude 1-2, tail over 20 degrees long. Early in December,. situated near the star Altair, magnitude 3-4 with a 5-degree tail. At the opening of January 1812, when approaching the evening twilight, visible as a fifth-magnitude object in Aquarius.
COMET C/1807 R1 (GREAT COMET). Visible with the unaided eye from early in Sept. until late Dec.; T = 1807 September 19. Discovered in the evening twilight of September 9, not far from the bright star Spica. Comet of first magnitude with a short tail, moving toward the northeast. Late in the month, at first magnitude with a 7- to 8-degree tail. During the middle of October, when situated Serpens, still of first or second magnitude and sporting two tails, the longer of which spanned 10 degrees. Crossed Hercules in the latter half of October and the first part of November, fading from second to fourth magnitude, but the main tail remained up to 5 degrees long. Situated near the bright star Deneb in mid-December, when approaching the limit of naked-eye visibility.