January 6, 2015 – The Amazing Sky

Tonight I caught a close-up of the green head and blue tail of Comet Lovejoy.

Clear skies tonight, Tuesday, January 6, allowed me to shoot Comet Lovejoy from home using a telescope and guiding system for a close-up view. I had just over half an hour of darkness between end of twilight at 6:30 and moonrise at 7:15 but that’s all I needed to grab several guided exposures.

This telescopic shot takes in a field of about 5 by 3 degrees, a little smaller than what most binoculars would show.

The image is a stack of four 2-minute exposures with the telescope guiding on the fast-moving comet. Comet Lovejoy is now at its closest point to Earth and moving fairly rapidly across the sky. So I guided on the comet, letting the stars trail slightly over the 8 minutes of exposure time.

The head of the comet glows bright green in photos, from glowing diatomic carbon, while the tail glows blue from other ionized gases streaming away from the head, or coma. The source of it all is a tiny icy nucleus completely hidden from view amid the glowing gases.

Comet Lovejoy was easy in binoculars, which showed a bare hint of the tail in dark skies. I could see the comet naked eye, but only by knowing just where to look. It appeared as a slightly fuzzy star, but unless you knew what you were looking at you wouldn’t know it was comet. This is a binocular comet for dark skies. But a very nice binocular comet.