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This drawing was made by Otto Wilhelm Struve (Pulkovo) on 1852 September 25. It shows both pieces of comet 3D/Biela, with component B being the brightest. North is toward the top right.
Discovery
The comet's first discovery came on 1772 March 8, when Jacques Leibax Montaigne (Límoges, France) found the comet just below naked-eye visibility. Observations ceased after 29 days, and no elliptical orbit could be computed. The comet passed closest to Earth (0.62 AU) on March 13.
The comet's second discovery was made by Jean Louis Pons (Marseille, France) on 1805 November 10. Then between magnitude 4 and 5, the comet displayed a weak coma, but no tail. It brightened during the following days and passed closest to Earth (0.04 AU) on December 9. The comet was last detected on December 14.
The comet's third discovery was made by Wilhelm von Biela (Josephstadt, Austria) on 1826 February 27. Modern analysis of the observations indicates the comet was then between magnitude 8 and 9. The comet was followed for 72 days, thus providing enough observations to establish a short-period orbit and enable links to be made to the earlier apparitions. The comet passed closest to Earth (0.96 AU) on April 19.
Historical Highlights
Some rather discordant orbits were calculated for the 1772 apparition before the comet's elliptical nature was realized. These orbits came from Joseph-Jérôme de Lalande (1774), Carl Friedrich Gauss (1806), and F. W. Bessel (1806). Following the comet's rediscovery in 1805, Bessel quickly published a parabolic orbit with a perihelion date of 1806 January 1.49, which immediately prompted Olbers to note a similarity to the comet of 1772. Gauss then took positions obtained during the period of November 16 and December 8, and determined a perihelion date as 1805 December 31.78. He also noted the similarity to the orbit of the comet of 1772, but added, "one cannot bring the elements substantially closer without disfiguring the agreement with the observations. The comet of 1772 came close to no planet that could have caused a large modification of its elements." During February of 1806, Gauss redetermined the orbit of the comet of 1772 and became convinced that it was identical to Pons' current comet. Although the first elliptical orbit was calculated by Bessel during April 1806, the period had been assumed as 33.86 years. The first true calculation of an elliptical orbit must be credited to Gauss, who determined the perihelion date as 1806 January 2.93 and the period as 4.74 years. Further investigation into the orbit of this comet basically ended because of the short period of time the comet was under observation. Work on this orbit finally resumed in 1826 after Biela had discovered a comet on February 27. Shortly after mid-March, several astronomers were pointing out the similarity between the orbits of the 1826 comet, and those seen in 1772 and 1805. The 1826 comet was followed until May 9, which provided enough observations for a fairly accurate determination of the orbit. Although Biela was the first to suggest a link between the 1826 comet and that seen in 1805, it was J. F. A. Gambart (1826) who successfully linked the apparitions.
Apparition of 1832: The comet was successfully recovered by John Frederick William Herschel (England) on 1832 September 24, and was last detected by Thomas Henderson (South Africa) on 1833 January 4. The comet never displayed a tail and the coma never exceeded a diameter of 3 arc minutes.
Apparition of 1839 (missed): This apparition was very unfavorable and the comet was not observed.
Apparition of 1846: The comet was found by de Vico (Italy) on 1845 November 26. The comet was fainter than expected, but steady brightened during December. In mid-January astronomers were surprised to see the comet had split into two pieces. Both nuclei were followed until the end of March, at which time the fainter was lost from view. The brighter nucleus continued to be followed until April 27.
Apparition of 1852: The comet was recovered by Secchi (Italy) on 1852 August 26. Only one nucleus remained visible until September 15, when the fainter nucleus was finally detected. Unfortunately this was not a favorable apparition and the comet was not seen after September 29.
Predictions following the 1852 apparition: The comet was never seen again. The 1859 apparition was very unfavorable, but that of 1865-1866 was very favorable. Numerous searches were made during the latter years, but no trace was found. Several astronomers suggested the comet had continued to break up and no longer existed. Interestingly, at the comet's next expected return in 1872, a major meteor storm occurred on November 27, with hourly rates peaking at 3000 per hour. Calculations revealed the meteor shower likely came from the orbit of comet Biela. Intense meteor displays were also noted during the comet's next expected returns in 1885 (15,000 per hour), 1892 (6,000 per hour), and 1899 (150 per hour). No notable meteor rates occurred in the years that followed and later searches for the comet as late as the early 1970s were never successful.
An interesting sidebar to this story developed in 2001. The NEAR-EARTH ASTEROID TRACKING program (NEAT) found a comet on May 11, which by May 15 was hinted at possibly being of short period on IAU Circular No. 7625. The short-period nature was confirmed on IAU Circular 7635 (2001 May 29), at which time it was also announced that S. Nakano (Japan) "has noted some rough similarity to the orbit of comet 3D/Biela."
Close approaches to planets: With the comet's breakup it is uncertain whether there is anything left. If pieces do remain, they must be small in order to have gone unseen for so many years. In addition, if pieces do remain, the breakup must have caused some considerable nongravitational effects and any attempt at orbit calculations into the 20th century would probably have been fruitless. Therefore, the close approaches are only shown for the period the comet was detectable during the late 18th and first seven decades of the 19th century. During this time there were seven close approaches to Earth and one close approach to Jupiter. (Calculated from available orbits by Gary W. Kronk)
- 0.63 AU from Earth on 1772 March 14 (contributed to comet's first discovery)
- 0.17 AU from Earth on 1778 December 2
- 0.39 AU from Jupiter on 1794 June 3
- decreased perihelion distance from 0.97 AU to 0.90 AU
- decreased orbital period from 6.85 to 6.71 years
- 0.035 AU from Earth on 1805 December 9 (contributed to comet's second discovery)
- 0.96 AU from Earth on 1826 April 19 (contributed to comet's third discovery)
- 0.55 AU from Earth on 1832 October 24
- 0.37 AU from Earth on 1846 March 20
- 0.22 AU from Earth on 1866 February 25
cometography.com
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