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Comet 22P Kopff.jpg
14" reflector imaged on 2009-06-27
Discovered by August Kopff
Discovery date August 23, 1906
1906 Q1, 1919 O1
Orbital characteristics A
Epoch January 1, 2003
Perihelion 1.583 AU
Semi-major axis 3.467 AU
Eccentricity 0.5433
Orbital period 6.457 a
Inclination 4.718°
Last perihelion May 25, 2009[1]
Next perihelion October 25, 2015[2]

Comet Kopff or 22P/Kopff is a periodic comet in our solar system. Discovered on August 23, 1906, it was named after August Kopff who discovered the comet. The comet was missed[1] on its November 1912 return, but was recovered on its June 1919 return. The comet has not been missed since its 1919 return and its last perihelion[3] passage was on May 25, 2009. A close pass by Jupiter in 1939 decreased the perihelion distance and orbital period.[4] The comet 22P/Kopff’s next expected perihelion[5][6] is October 25, 2015.


22P/Kopff was discovered[7] at Königstuhl Observatory on Heidelberg, Germany. Kopff analyzed photographic plates which he exposed on August 20, 1903 against pre-discovery images of the same region. On August 23, 1903, Kopff concluded it to be a comet with an estimated magnitude of 11. On mid-September 1906, the short-period nature of the comet was recognized by a team headed by Kiel Ebell of the Berkeley Astronomical Department. The comet was missed when it made a return on November 25, 1912 however on June 25, 1919, astronomers recovered the comet. The comet was located less than three days from the predicted position. Over the next several returns to Earth, none were notable until the August 11, 1945 comet’s return. It was during this time that the magnitude was recorded at 8.5. The sudden burst of brightness was attributed to Jupiter altering the comet’s orbit between the years of 1939 to 1945. The October 1951 return was labeled as unique due to the predictions falling 3 magnitudes fainter than what was expected. A very close pass to Jupiter increased the comet’s perihelion distance to 1.52 AU as well as subsequently increasing the orbital period to 6.31 years. At the 14th appearance[8] of 22P/Kopff on July 2, 1996, Carl W. Hergenrother was able to record a stellar magnitude of 22.8 using the 1.5-m reflector at the Catalina Sky Survey.

The comet nucleus is estimated to be 3.0 kilometers in diameter with an albedo of 0.05.[9]


  1. ^ a b "22P/Kopff (Returns and Appearances)". Seiichi Yoshida Comet Catalog. Retrieved 2010-02-24. 
  2. ^ Syuichi Nakano (2009-02-16). "22P/Kopff (NK 1749)". OAA Computing and Minor Planet Sections. Retrieved 2010-03-04. 
  3. ^ "22P/Kopff (2009)". Seiichi Yoshida Comet Catalog. Retrieved 2010-02-25. 
  4. ^ 22P at Kazuo Kinoshita's Comets
  5. ^ "22P/Kopff". Nakano Note (Nakano wa Kangaeru noda) NK 1749. Retrieved 2010-02-24. 
  6. ^ "Periodic Comets 1P to 50P". Gary W. Kronk's Cometography. Retrieved 2010-02-23. 
  7. ^ "22P/Kopff". Gary W. Kronk's Cometography. Retrieved 2010-02-25. 
  8. ^ "22P/Kopff (1996)". Seiichi Yoshida. Retrieved 2010-02-25. 
  9. ^ "JPL Small-Body Database Browser: 22P/Kopff". Jet Propulsion Laboratory. 2010-01-04 last obs. Retrieved 2010-02-25. 

External links[edit]

Periodic comets (by number)
22P/Kopff Next