|Discovered by||Theodor Brorsen and Joel Metcalf|
|Discovery date||July 20, 1847|
|1847 O1, 1919 Q1, 1989 N1|
|Orbital characteristics A|
|Epoch||October 1, 1989|
|Semi-major axis||17.07 AU|
|Orbital period||70.52 a|
|Last perihelion||September 11, 1989|
|Next perihelion||June 8, 2059|
Comet 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). It was first discovered by Theodor Brorsen (Altona, Germany) on July 20, 1847, and again by Kaspar Schweizer (Moscow) on August 11, 1847, the prediction was made it would return between 1919 and 1922.
On August 21, 1919, the comet was recovered by Reverend Joel Hastings Metcalf (Camp Idlewild, Vermont, USA) as 8th magnitude. Additional discoveries were made by Edward Barnard (Yerkes Observatory, Wisconsin, USA) 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.
- "JPL Small-Body Database Browser: 23P/Brorsen-Metcalf". Jet Propulsion Laboratory. 1989-09-09 last obs. Retrieved 2011-10-17.
- Seiichi Yoshida (2005-11-09). "23P/Brorsen-Metcalf". Seiichi Yoshida's Comet Catalog. Retrieved 2012-02-19.
- Horizons output. "Observer Table for Comet 23P/Brorsen-Metcalf (1989)". Retrieved 2012-02-19. (Observer Location:@sun)
- Orbital simulation from JPL (Java) / Horizons Ephemeris
- 23P at Kronk's Cometography
- 23P at Kazuo Kinoshita's Comets
- 23P at Seiichi Yoshida's Comet Catalog
|Periodic comets (by number)|