C/2012 E2 (SWAN)

Comet C/2012 E2 (SWAN) was a

observed in SWAN imagery.

Discovery

On March 8, 2012, Ukrainian amateur astronomer Vladimir Bezugly reported an unknown comet in 3 images taken by the SWAN instrument on board the SOHO spacecraft. Further study of this object revealed that it was a Kreutz group sungrazer with a perihelion date on March 15, 2012. This was particularly interesting because no Kreutz sungrazer had ever been bright enough to be observed by the SWAN cameras, not even Comet C/2011 W3 (Lovejoy) which was visible to the naked-eye three months earlier. This meant that Comet SWAN had a chance of being an exceptionally bright comet.^[1]

SECCHI and LASCO Observations

The SECCHI HI1 camera on board the STEREO-B spacecraft was the first to observe the comet after the SWAN instrument. It entered the field of view on March 11 and appeared reasonably bright, though not as bright as it could have been. The comet entered the visibility of

. SECCHI's COR instruments on both STEREO spacecraft also observed the comet's final moments.^[2][1][3]

Other observations

The reason of the comet's brightness in SWAN remains unknown, though it is thought that the comet experienced an outburst a few days before discovery which rendered it much brighter than it was otherwise.^[1] No ground-based observations of the comet were available.

Due to a short 2-day observation arc, the long-term trajectory of the comet is poorly constrained. The orbital period is unknown with an orbital inclination of 144 degrees.^[4]

References