Comet Lemmon (C/2012 F6) named for its discovery last year as part of the Mount Lemmon (Arizona) Survey, is currently sweeping through southern skies, brighter than expected but still just below naked-eye visibility. Image © Peter Ward (Barden Ridge Observatory)
Comet Lemmon sports a stunning lime green coma and faint divided tail in this telescopic image from February 4. The greenish tint comes from the coma’s diatomic C2 gas fluorescing in sunlight. Captured from an observatory near Sydney, Australia, the color composite is constructed from a series of individual exposures registered on the comet. Across the 1 degree wide field of view, the star trails are a consequence of the comet’s relatively rapid motion against the background of stars near the South Celestial Pole.