The earliest observation of this comet occurred on the evening of February 5, 1843. This observation and another on February 11, were mentioned by Encke as having appeared in a newspaper. The story originated out of New York. Although no details were given for the February 5th observation, that of February 11 placed the comet "in the vicinity of Beta Ceti." Encke examined the orbit of this comet and found it was fairly close to Beta Ceti on the 11th, and he concluded that both observations were probably real. Calculations by the Author indicate the actual dates, in universal time, were probably February 6.0 and February 12.0. The comet was situated very low in the southwest at the end of astronomical twilight and, from New York, the head would have set about one hour later. At the time of the observation of February 12, the comet was situated about 6.5° from Beta Ceti. Edward Claudius Herrick reported in the April-June 1843 issue of the American Journal of Science, "It appears quite probable that the train of this comet was seen in the evening [sky] before the perihelion passage, at Bermuda, Philadelphia, and Porto Rico, on the 19th, 23d and 26th of February," [respectively]. The comet had passed closest to Earth (0.8690 AU) on January 27.
In 1901, Kreutz took about 200 precise positions obtained during the period of 1843 March 5 to Apr. 19, and computed the following orbit:
Daylight Observations: On February 27.66, Captain Peleg Ray (Concepcion, Chile) observed this comet [at 11 a.m.] a little east of the sun. On February 28, observers at New Bedford, Massachusetts, said the comet was as bright as Venus, with a tail 3° long. In the Ile-de-France the comet was seen during the day. On February 28.47, Giovanni Battista Amici (Florence) observed the comet [at noon] and said, "the mass, examined by an opera glass, to be like a flame, badly defined, three times as long as it was wide, very luminous towards the sun, and a little smoky at the east." On February 28.52, "a large part of the adult population" of Waterbury, Connecticut, first observed a comet at 7:30 a.m. "east of and below the sun," G. L. Platt, M. C. Leavenworth, S. W. Hall, Alfred Blackman, and N. J. Buel gave particulars of these observations, noting the comet remained visible until 3 p.m., when skies clouded up. They described it as a round coma with a pale tail extending 2° to 3° and "melting away into the brilliant sky." The nucleus was detected with the naked eye and was distinctly round, "its light equal to that of the moon in midnight in a clear sky; and its apparent size about one eighth the area of the full moon." On February 28.70, an observer in Woodstock, Vermont, saw the comet [at noon] and compared it to a small, white cloud, 3° long. He added that when viewed with a telescope, "it presented a distinct and most beautiful appearance,-exhibiting a very white and bright nucleus, and a tail dividing near the nucleus into two separate branches, with the outer sides of each branch convex, and of nearly equal length, apparently 8° or 10°, and a space between their extremities of 5° or 6°." On February 28.82, Captain J. G. Clarke (Portland, Maine) observed the comet in broad daylight. He determined that the nearest limb of the nucleus was situated 4° 06' 15" from the sun's farthest limb and the nucleus and tail appeared as well-defined "as the moon on a clear day." He added that the comet looked like "a perfectly pure white cloud, without any variation, except a slight change near the head, just sufficient to distinguish the nucleus from the tail at that point." On February 28.97, Bowring (Chihuahua, Mexico) observed the comet at a distance of 3° 53' 20" from the sun.
Sometime during the period of January 30 and February 28, 1843, the Chinese noted a large "broom-star" comet "was seen in the day time."
March 1-2: As March began numerous observers around the world reported that only the tail was visible after sunset. On the 1st a passenger aboard the Lawrence (en route from Sydney to Concepción) described it as "a white streak of light, inclined at an angle of 40° to the horizon, and was imagined to be the zodiacal light." On the 2nd Captain P. P. King (Royal Navy, station at Port Stephens, New South Wales), reported the appearance of the tail was "producing great alarm among the natives." The Bishop of Australia made distinct notes about the comet's appearance and noted, "my attention was drawn to the remarkable spectacle of a definite portion of the tail being deflected from the axis, or direction in which the general body of light continued to proceed. Perhaps, about one-sixth of the train might be thus drawn aside from that which may be termed the natural direction, so as to form therewith, at the point of separation, an angle which I should calculate to be about three degrees...."
March 3-6: On the 3rd Piazzi Smyth (Royal Observatory, Cape of Good Hope, South Africa) described the nucleus as "a planetary disk, from which rays emerged in the direction of the tail." He added, "To the naked eye there appeared a double tail, about 25° in length, the two streamers making with each other an angle of about 15°, and proceeding from the head in perfectly straight lines. From the end of the forked tail, and on the north side of it, a streamer diverged at an angle of 6° or 7° towards the north, and reached a distance of upwards of 65° from the comet's head; a similar, though much fainter, streamer was thought to turn off south of the line of direction of the tail." King observed the main tail, as well as "a second ray [which] extended obliquely from it...making with it an angle of 10°." On the 4th Commander Close, of the Ellenborough, said the nucleus was equal to a star of magnitude 2-3. He added, "the tail had a darkish line from its nucleus through the centre to the end; it was occasionally brilliant enough to throw a strong light on the sea. The tail was observed to have considerable curvature." King observed the nucleus with a refractor and described it as a "reddish stellar spot" with well-defined edges and about 1' in diameter. The comet was 8° above the horizon. H. A. Cooper (Pernambuco, Brazil) described the comet "as particularly small, without any nebulosity, but of extreme brightness, of a golden hue, and a line of the same bright color may be distinctly traced, running directly from it into the tail, for 4° or 5°; the tail is perhaps 30° in length, and is of a brilliant silver color, perfectly opaque, but becoming less and less dense until it is lost in space." On March 5 Smyth said, "the appearance of the comet was considerably changed [since the 3rd]; the angle of the north streamer with the direction of the tail had been diminishing, and was now south; it had also diminished in brightness. The total length was about 35°. All the rays proceeding from the head were now of uniform brightness, excepting one bright streak, which could be traced along the tail." On March 6 Caldecott measured the tail as 36° in length and said a 7.5-foot focal length telescope showed "The nucleus of the head presented rather a well-defined planet-like disc, the diameter of which I estimated to be about 12", and that of the nebulosity surrounding it at about 45". The tail had a dark appearance along its axis, as if hollow; and at about half way from the head, it even appeared to separate slightly into two parts, the upper one being rather longer than the other." Gilbert (St. Helena island in South Atlantic Ocean) said the tail was 42.9° long. Kay estimated the tail length as 23.3°. A passenger aboard the Lawrence said the tail was 50° long and was composed of "two streams of light, the outside edges being clear and well-defined."
March 7-12: Observers estimated tail lengths ranging from 26 to 43 degrees on the 7th. An observer in New Haven, Connecticut, had to contend with a 6-day-old moon, but still described the comet's tail as "a long, narrow, and brilliant beam, slightly convex upwards, the lower end being apparently below the horizon." On the 9th Haile estimated the tail as 35.2° long, while Kay said it extended 39°. By March 11 Kay noted that tail was no longer stellar in appearance but rather had the appearance "of a large star covered with a thin film of cloud, or viewed through a telescope which had not been adjusted to focus." Tail lengths ranged from 20 to 45 degrees in length. On March 12, Edward Cooper (Nice, France) observed the comet in the evening sky after his servant had called attention to it. He described it as "a long white light near the western horizon which had somewhat the appearance of that kind of cloud commonly called cirrostratus. Sears Cooke Walker and E. Otis Kendall (Central High School Observatory, Philadelphia, Pennsylvania) first detected the nucleus in the comet searcher as a "well-defined disc larger than Jupiter in the same instrument".
March 13-20: On the 13th Caldecott measured the diameter of the "bright part or disc of the head" with a parallel wire micrometer and determined it as 11". He added that the nebulosity surrounding this nucleus was "about four times the diameter" of the disc. Tail lengths were still in the 30 to 45 degree range. On March 17 John Frederick William Herschel said the comet appeared as a "vivid luminous streak,". Herschel added that the tail exhibited no bifurcation, and was nearly parallel to the equator, although a slight curvature was suspected. Captain John Grover (Pisa) said he "saw a luminous arc in the heavens, extending from a spot about a degree to the south of Rigel to some clouds which bounded the western horizon. It was about 40 minutes in width; the edges sharply and clearly defined." Tail lengths generally ranged from 30 to 43 degrees on the 17th, 34 to 40 degrees on the 18th, and 40 to 48 degrees on the 20th.
March 21-31: On the 22nd Maclean noted, "although the sky was very clear, the nucleus was with difficulty perceptible, from which it appeared that the comet was increasing its distance from us with immense rapidity." He indicated the tail extended about 37°. On March 23, the crew of the Dublin estimated the tail was about 36.4° long. Maclean found the tail was 38° long. On March 24, Haile estimated the tail was 35.2° long. Kay said the tail was 39° long. On March 26, Maclean found the tail about 35° long. He added, "Through ordinary land-glasses it still appeared as if there was a condensation of brighter matter in the centre of the head." On March 27 Kay said the tail was 35° long. On March 31 Caldecott said skies were mostly cloudy, but occasional glimpses of the tail was detected through breaks in the clouds.
April: On April 2, Franzini said the comet was very faint and that the nucleus was not observed. On the 3rd an observer in New Haven last detected the comet with the naked eye and said it was "barely discernible." Caldecott tried to view the comet with an equatorially-mounted, 7.5-foot focal length refractor on the 6th, but nothing could be perceived. On April 11 Leichhardt last detected the comet while at F. T. Rusden's station near Gwydir Falls (New South Wales). He said, "by straining my eyes, I could just make out the last faint glimmer of it...."
Last Detected: The comet was last detected on April 19.76, by Maclear.
Cultural Effect: It should be added that this comet made a strong impression on the people of the time. Moncure Daniel Conway included a particularly interesting reference to this comet in his autobiography. He wrote, "But the greatest sensation was caused by the comet of 1843. There was a widespread panic, similar, it was said, to that caused by the meteors of 1832. Apprehending the approach of Judgement Day, crowds besieged the shop of Mr. Petty, our preaching tailor, invoking his prayers. Methodism reaped a harvest from the comet. The negroes, however, were not disturbed;-they were, I believe, always hoping to hear Gabriel's trump."