20D/Westphal
Lost comet
title: "20D/Westphal" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["periodic-comets", "destroyed-comets", "halley-type-comets", "numbered-comets", "near-earth-comets", "lost-comets", "astronomical-objects-discovered-in-1852"] description: "Lost comet" topic_path: "general/periodic-comets" source: "https://en.wikipedia.org/wiki/20D/Westphal" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Lost comet ::
::data[format=table title="Infobox comet"]
| Field | Value |
|---|---|
| name | 20D/Westphal |
| discoverer | J. G. Westphal |
| discovery_date | July 24, 1852 |
| designations |
1913d | | epoch | 1913-11-09 (JD 2420080.5) | | semimajor | 15.642 AU | | perihelion | 1.2540 AU | | aphelion | 30.030 AU | | eccentricity | 0.9198 | | period | 61.87 yr | | inclination | 40.890° | | last_p | January 3, 1976? (unobserved) | | next_p | May 4, 2038? (lost since 1913) | ::
| name=20D/Westphal | image= | discoverer=J. G. Westphal | discovery_date=July 24, 1852 | designations=
1913d | epoch=1913-11-09 (JD 2420080.5) | semimajor=15.642 AU | perihelion=1.2540 AU | aphelion=30.030 AU | eccentricity=0.9198 | period=61.87 yr | inclination=40.890° | last_p=January 3, 1976? (unobserved) | next_p=May 4, 2038? (lost since 1913)
20D/Westphal was a periodic comet with an orbital period of 61 years. It fits the classical definition of a Halley-type comet (20 years
The comet was originally discovered by the German astronomer J. G. Westphal (Göttingen, Germany) on July 24, 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 September 27, 1913, by Pablo T. Delavan (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 November 26, 1913. It was predicted to return in 1976 but was never observed, and is now considered a lost comet.
References
|date=2004-02-21 |title=20D/Westphal |publisher=Seiichi Yoshida's Comet Catalog |author=Seiichi Yoshida |url=http://www.aerith.net/comet/catalog/0020D/index.html |access-date=2012-02-20}}
|type=1913-10-13 last obs |title=JPL Small-Body Database Browser: 20D/Westphal |url=http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=20D |publisher=Jet Propulsion Laboratory |access-date=2012-07-26}}
|title=Horizons Batch for 20D/Westphal (90000307) on 2038-May-04 |publisher=JPL Horizons |type=Perihelion occurs when rdot flips from negative to positive |url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%27DES%3D20D%3BCAP%27&START_TIME=%272038-May-04%27&STOP_TIME=%272038-May-05%27&STEP_SIZE=%271%20hours%27&QUANTITIES=%2719%27 |archive-url=https://web.archive.org/web/20230216094334/https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%2790000306%27&START_TIME=%272038-May-04%27&STOP_TIME=%272038-May-05%27&STEP_SIZE=%271%20hours%27&QUANTITIES=%2719%27 |archive-date=2023-02-16 |url-status=live |accessdate=2023-02-11}} (JPL#19 Soln.date: 2003-Apr-11)
References
- (April 1984). "Disappearance and disintegration of comets". Icarus.
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