Comet Yi–SWAN

Comet Yi–SWAN

C/2009 F6 (Yi–SWAN)
Discovered by Dae-am Yi, SWAN instrument on SOHO spacecraft
Discovery date March 26, 2009
Orbital characteristics A
Epoch 2009-May-22
Aphelion 904 AU[1]
Perihelion 1.274072 AU
Semi-major axis 453 AU[1]
Eccentricity 0.997031
Orbital period ~9,600 yr[1]
Inclination 85.7668
Last perihelion April 7, 2009
Next perihelion 13462

Comet C/2009 F6 (Yi–SWAN) is a non-periodic comet which appeared in March 2009.

It was first discovered by Korean amateur astronomer Dae-am Yi on March 26, 2009, using a Canon 5D camera and 90-mm lens. It is believed to be the first comet discovered by a Korean in the modern age.[2] Independently, on April 4 Rob Matson reported he had discovered a comet in the SWAN instrument photographs on the SOHO (Solar and Heliospheric Observatory) spacecraft website.[3]

The comet was not bright enough to be seen by the naked eye, but was theoretically visible through amateur telescopes. However, it was harder to see than predicted, as it remained quite small and did not form much of a visible tail. It reached a peak magnitude around +8.5 in April into May, and passed 1.5 degrees south of the Double cluster in Perseus on April 23.[3]


  1. ^ a b c   (Solution using the Solar System Barycenter and barycentric coordinates. Select Ephemeris Type:Elements and Center:@0)
  2. ^ Meyer, Maik. "Forum communication". Retrieved 2009-04-13. 
  3. ^ a b Sinnott, Robert (2009-04-08). "New Circumpolar Comet Yi-SWAN".  

External links

  • "JPL Small-Body Database Browser". NASA. 
  • Comet C/2009 F6 Yi-SWAN – Heavens-Above