This image of Comet Lovejoy (officially: C/2014 Q2) was taken by Lillian Campbell and Matthew Levin-Nussbaum using the Perkin Observatory on Saturday, January 10th. The field of view is a little under two degrees wide, and the comet was located west of the
A comet is a large, icy dirtball that releases gases and particles -- forming an atmosphere (the "coma") and sometimes a tail. While the solid nucleus may be just a few miles wide, the coma can have a diameter up to millions of miles across (larger than the Sun), and the tail can stretch for hundreds of millions of miles (larger than our
distance to the Sun). As organic molecules have been found on comets, it has been speculated that life on Earth may have come from comets.
The trails in the background of this image are from stars -- and our processing method. This image was produced from 40 digital images that have been averaged (this makes the "signal," the light from the object of interest, stand out more against the "noise," such as the brightness of the night sky itself, resulting in an image that reveals
much greater detail). Before averaging them, we precisely aligned all of the images relative to the comet. This alignment causes the effect of star trails because the comet's motion does not match the usual motion of the stars. As the stars change position in the comet-aligned frames, averaging all of the frames washes away the brightness of the stars -- but reveals awesome detail in the comet's very faint tail!
For a look at Comet Lovejoy through the telescope, visit the Perkin Observatory this month. Follow the Observatory on Twitter (@Dublin_Astro) for time-sensitive details.