Langbahn Team – Weltmeisterschaft

21P/Giacobini–Zinner

21P/Giacobini–Zinner
Comet Giacobini–Zinner photographed from Moscow, Russia on 9 September 2018.
Discovery
Discovered byMichel Giacobini
Ernst Zinner
Discovery date20 December 1900
23 October 1913
Designations
P/1900 Y1
P/1913 U1
1900 III; 1913 V; 1926 VI;
1933 III; 1940 I; 1946 V;
1959 VIII; 1966 I; 1972 VI;
1979 III; 1985 XIII; 1992 IX
Orbital characteristics[3][4]
Epoch13 November 2017 (JD 2458070.5)
Observation arc4,922 days (13.48 years)
Number of
observations		1,993
Aphelion5.987 AU
Perihelion1.013 AU
Semi-major axis3.492 AU
Eccentricity0.71047
Orbital period6.549 years
Inclination32.002°
195.40°
Argument of
periapsis		172.81°
Last perihelion10 September 2018[1]
Next perihelion25 March 2025[2]
TJupiter2.465
Earth MOID0.018 AU
Jupiter MOID0.248 AU
Physical characteristics[4]
Dimensions2.0 km (1.2 mi)
Comet total
magnitude (M1)		13.2

Comet Giacobini–Zinner (officially designated as 21P/Giacobini–Zinner) is a periodic comet in the Solar System. It was discovered by Michel Giacobini, who observed it in the constellation of Aquarius on 20 December 1900. It was recovered two orbits later by Ernst Zinner, while he was observing variable stars near Beta Scuti on 23 October 1913.

Physical properties

The comet nucleus is estimated to be 2.0 km (1.2 mi) in diameter.[4] During its apparitions, Giacobini–Zinner can reach about the 7-8th magnitude,[5] but in 1946 it underwent a series of outbursts that made it as bright as 5th magnitude. It is the parent body of the Giacobinids meteor shower (also known as the Draconids). The comet currently has a minimum orbit intersection distance to Earth of 0.035 AU (5.2 million km).[4]

During the apparition of 2018, the optical spectra have revealed the comet is depleted in carbon-chain molecules and carbon dioxide, likely indicating its origin in relatively warm portion of the Solar system.[6]

Exploration

See also: List of minor planets and comets visited by spacecraft

Giacobini–Zinner was the target of the International Cometary Explorer spacecraft, which passed through its plasma tail at a distance of 7,800 km (4,800 mi) on 11 September 1985, becoming the first comet ever visited in space exploration.[7] Earlier in the same month the comet was observed by the Pioneer Venus Orbiter.[8] In addition, Japanese space officials considered redirecting the Sakigake interplanetary probe toward a 1998 encounter with Giacobini–Zinner, but that probe lacked the propellant for the necessary maneuvers and the project was abandoned.

2025 Perihelion

21P/Giacobini-Zinner will next pass perihelion on 25 March 2025, and will have its closest approach to Earth 4 days before, on 21 March. It is expected to brighten to magnitude ~11.[9]

References

  1. ^ S. Nakano (5 February 2012). "21P/Giacobini-Zinner (NK 2191)". OAA Computing and Minor Planet Sections. Retrieved 18 February 2012.
  2. ^ S. Yoshida. "21P/Giacobini–Zinner". www.aerith.net. Retrieved 5 January 2025.
  3. ^ "Horizons Batch for 21P/Giacobini-Zinner (90000322) on 2025-Mar-25" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Retrieved 10 April 2021. (JPL#K182/14 Soln.date: 2021-Mar-23)
  4. ^ a b c d "21P/Giacobini–Zinner – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 10 January 2016.
  5. ^ B. King (29 August 2018). "Comet 21P/Giacobini-Zinner Shines in September". Sky & Telescope. Retrieved 15 September 2018.
  6. ^ Y. Shinnaka; H. Kawakita; A. Tajitsu (2020). "High-resolution Optical Spectroscopic Observations of Comet 21P/Giacobini–Zinner in its 2018 Apparition". Astronomical Journal. 159 (5): 203. arXiv:2004.11008. Bibcode:2020AJ....159..203S. doi:10.3847/1538-3881/ab7d34.
  7. ^ C. Stelzried; L. Efron; J. Ellis (1986). Halley Comet Missions (PDF) (Report). NASA. pp. 241–242. TDA Progress Report 42-87. Public Domain This article incorporates text from this source, which is in the public domain.
  8. ^ P. Ulivi; D. M. Harland (2007). Robotic Exploration of the Solar System Part I: The Golden Age 1957–1982. Springer. p. 281. doi:10.1007/978-0-387-73983-0. ISBN 978-0-387-49326-8. ISSN 2945-7475.
  9. ^ G. van Buitenen. "21P/Giacobini–Zinner". astro.vanbuitenen.nl. Retrieved 8 November 2024.


Numbered comets
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Quelle: https://en.wikipedia.org/wiki/Comet_Giacobini-Zinner