20D/Westphal was a Halley-type comet with an orbital period of 61 years. The comet appeared to disintegrate during the 1913 apparition and has not been observed in years.
Observational history The comet was originally discovered by the German astronomer Justus Georg Westphal from Göttingen, Germany on 24 July 1852. It was independently discovered by the American astronomer Christian Heinrich Friedrich Peters (Constantinople) on August 9. The comet exhibited many flunctuations in intristic brightness and reached an apparent magnitude of around 4 while a dust tail was also observed. It was last observed about 120 days after perihelion.
The comet was recovered on 27 September 1913, by Pablo T. Delavan from the La Plata Astronomical Observatory about 60 days before perihelion. However, the comet faded as it approached the Sun, losing its central condensation and the nucleus becoming elongated. The plates of the comet indicate that the disintegration began on October 1, when the comet was reported to be visible with the naked eye using averted vision. It was last observed on 26 November 1913. It was predicted to return in 1976 but was never observed, and is now considered a lost comet.
References
External links
at the Minor Planet Center database 20D/Westphal at the Infrared Processing and Analysis Center 20D/Westphal at Gary W. Kronk's Cometography 20D/Westphal at Kazuo Kinoshita's Comets