![]() Comet Brorsen-Metcalf by
Edward Emerson Barnard on 6 October 1919 | |
Discovery | |
---|---|
Discovered by | Theodor Brorsen and Joel Metcalf |
Discovery date | July 20, 1847 |
Designations | |
1847 O1, 1919 Q1, 1989 N1 | |
Orbital characteristics | |
Epoch | October 1, 1989 |
Aphelion | 33.65 AU |
Perihelion | 0.478 AU |
Semi-major axis | 17.07 AU |
Eccentricity | 0.972 |
Orbital period | 70.52
yr
[1] 69y 8m 28d (perihelion to perihelion) |
Max. orbital speed | 60.2 km/s @ perihelion [2] |
Inclination | 19.33° |
Last perihelion | September 11, 1989 [1] |
Next perihelion | June 8, 2059 [2] [3] [4] |
23P/Brorsen–Metcalf is a periodic comet with an orbital period of 70 years. It fits the classical definition of a Halley-type comet with (20 years < period < 200 years). [1] It was first discovered by Theodor Brorsen at the Altona Observatory on July 20, 1847, and again by Kaspar Schweizer ( Moscow) on August 11, 1847. It was predicted that it would reappear between 1919 and 1922.
On August 21, 1919, the comet was recovered by Joel Hastings Metcalf ( Camp Idlewild, Vermont, United States) as 8th magnitude. Additional discoveries were made by Edward Barnard ( Yerkes Observatory, Wisconsin, United States) on August 22, Michel Giacobini ( Paris, France), Ostrovlev ( Theodosia, Crimea) and Selavanov ( Saint Petersburg). By the end of September 1919 it was confirmed as being the same as Brorsen's comet.
The comet became visible with naked eye as a small hazy spot of light and on 6 October 1919 it was estimated to have a magnitude of 4.5. The comet had a slender tail with a length of 8,5 degrees. On the photographs of the comet on 22 October 1919 a disconnection event of the tail was visible, that probably started on 20 October. [5]
The comet was recovered by the Palomar Observatory on 4 July 1989, when it had an estimated magnitude of 15, while Alan Hale estimated visually that it had a magnitude of 11.5 on 7 July. The comet brightened rapidly during July and by the end of the month it was reported to have an apparent magnitude of 7-7.5, while developing a short tail. The comet reached its perigee on 6 August, at a distance of 0.62 AU, while its perihelion was on 11 September. Between the two dates the comet had a magnitude between 5 and 6 and was reported to be visible by naked eye. In September the tail grew longer and was reported visually to have a length of about 7 degrees. The comet faded in the second half of September and the diminishing solar elongation hindered further observations. [6] During the 1989 apparition, the comet became the first comet to be definitely detected in submillimeter wavelengths. [7]
last obs. used 1989-09-09
![]() Comet Brorsen-Metcalf by
Edward Emerson Barnard on 6 October 1919 | |
Discovery | |
---|---|
Discovered by | Theodor Brorsen and Joel Metcalf |
Discovery date | July 20, 1847 |
Designations | |
1847 O1, 1919 Q1, 1989 N1 | |
Orbital characteristics | |
Epoch | October 1, 1989 |
Aphelion | 33.65 AU |
Perihelion | 0.478 AU |
Semi-major axis | 17.07 AU |
Eccentricity | 0.972 |
Orbital period | 70.52
yr
[1] 69y 8m 28d (perihelion to perihelion) |
Max. orbital speed | 60.2 km/s @ perihelion [2] |
Inclination | 19.33° |
Last perihelion | September 11, 1989 [1] |
Next perihelion | June 8, 2059 [2] [3] [4] |
23P/Brorsen–Metcalf is a periodic comet with an orbital period of 70 years. It fits the classical definition of a Halley-type comet with (20 years < period < 200 years). [1] It was first discovered by Theodor Brorsen at the Altona Observatory on July 20, 1847, and again by Kaspar Schweizer ( Moscow) on August 11, 1847. It was predicted that it would reappear between 1919 and 1922.
On August 21, 1919, the comet was recovered by Joel Hastings Metcalf ( Camp Idlewild, Vermont, United States) as 8th magnitude. Additional discoveries were made by Edward Barnard ( Yerkes Observatory, Wisconsin, United States) on August 22, Michel Giacobini ( Paris, France), Ostrovlev ( Theodosia, Crimea) and Selavanov ( Saint Petersburg). By the end of September 1919 it was confirmed as being the same as Brorsen's comet.
The comet became visible with naked eye as a small hazy spot of light and on 6 October 1919 it was estimated to have a magnitude of 4.5. The comet had a slender tail with a length of 8,5 degrees. On the photographs of the comet on 22 October 1919 a disconnection event of the tail was visible, that probably started on 20 October. [5]
The comet was recovered by the Palomar Observatory on 4 July 1989, when it had an estimated magnitude of 15, while Alan Hale estimated visually that it had a magnitude of 11.5 on 7 July. The comet brightened rapidly during July and by the end of the month it was reported to have an apparent magnitude of 7-7.5, while developing a short tail. The comet reached its perigee on 6 August, at a distance of 0.62 AU, while its perihelion was on 11 September. Between the two dates the comet had a magnitude between 5 and 6 and was reported to be visible by naked eye. In September the tail grew longer and was reported visually to have a length of about 7 degrees. The comet faded in the second half of September and the diminishing solar elongation hindered further observations. [6] During the 1989 apparition, the comet became the first comet to be definitely detected in submillimeter wavelengths. [7]
last obs. used 1989-09-09