This Week For Skywatchers: Comet Lovejoy

Comet Lovejoy has been brightening the night sky since December 2014, when it began to shine at fifth magnitude, at the very edge of naked-eye visibility. The comet, with its spectacular tail, has been visible to watchers with binoculars and telescopes through the dark moonless nights of mid-January and mid-February. This week, stargazers in the northern hemisphere should also be able to see it as it passes through Perseus, low in the northwestern sky. This will also be the comet’s goodbye to skywatchers, as it will dim to sixth magnitude by the end of the month and to ninth magnitude by the time the dark nights roll around mid-March. At that time, it will only be visible through telescopes.
Comet Lovejoy (C2014/ Q2) is the fifth comet discovered by amateur Australian astronomer Terry Lovejoy, on its first visit to the inner solar system in 11,000 years. Like many found in the Southern Hemisphere, Lovejoy is a very long-period comet, which are characterized by highly eccentric orbits and periods that can range anywhere from 200 years to thousands of years. Its closest approach to earth occurred just over a month ago, on January 15, 2015. However, gravitational forces in the inner solar system have altered Comet Lovejoy’s orbit during this transit, so that its next visit to the solar system will be 8,000 years from now.
Specifically, in photographs, the comet can be seen as a small, icy green core with a long blue tail pointing away from the sun. Photographer and amateur astronomer Chris Schur writes: “I have both viewed and imaged hundreds of comets, but none quite like this one! The two bright, band-like rays in the tail are unprecedented.” The core of the comet is ball of dirty ice not more than a mile or two in diameter, but the coma, the visible gaseous cloud surrounding the nucleus, is about 400,000 miles across. According to reports, the tail has also disappeared and reappeared a few times.

Seen through binoculars, the comet appears as a fuzzy ball. But don’t take our word for it. See for yourself as Lovejoy flies by this week. A skychart with its locations in February and March can be found here.