On a nice clear morning of 2025 April 20 UT, Comet C/2025 F2 (SWAN) was magnitude 9.8 as calculated from 4x20 second images thru a green filter in an aperture diameter of 3'. The comet coma was 2.5' wide, the tail was 2' long at a position angle of 313 degrees from the comet coma. The comet was at an altitude of 5.5 degrees just before the beginning of twilight and the Moon was only 56% illuminated. The ion tail is gone and the dust tail is not very impressive. When looking at the comet's magnitude, the comet has been very quiet since April 9 when it was magnitude 9.3, fading slowly as it approaches perihelion in its orbit on May 1. |
Page last updated: Wed 30 Apr 23:55:10 BST 2025