Watch a Green Comet Streak Across the Sky for Christmas

Comet Lovejoy is brightening faster than expected, putting on a show you can see for yourself this holiday season.
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This illustration shows comet Lovejoy's close encounter with the globular cluster M79 on the night of December 28, 2014.


Just in time for the holidays, the skies are serving up a special cosmic gift: a brightening comet that may not have been in our part of the solar system for nearly 12,000 years.

Discovered only this past August, comet Lovejoy (C/2014 Q2) is now quickly brightening to naked-eye visibility as it moves from the deep southern sky into prime viewing location for observers throughout the Northern Hemisphere. The comet is already putting on a Christmas show, glowing green thanks to molecules that glow when hit by the sun's solar wind.

This icy visitor to the inner solar system was first spotted by its namesake, Terry Lovejoy, an Australian astronomer using a common backyard telescope with only an eight-inch mirror. He spotted the comet while it was still a very faint 15th magnitude.

The comet wasn't predicted to become visible with the unaided eye until late January or February 2015. But comets can be unpredictable, with chaotic surface activity as they heat up and melt while nearing the sun during orbit. Since summer, the comet's brightness has shot up by hundreds of times.

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This diagram shows the orbit and location of comet Lovejoy on Christmas week in relation to the orbits of Earth and its neighboring planets. Note that the comet is approaching the inner solar system nearly perpendicular to Earth's orbit; that's the reason the comet is appearing to switch from a Southern to Northern Hemisphere object in the sky over the next week or so.


In fact, some observers in the Southern Hemisphere are reporting that it has brightened to magnitude 6, meaning that it has technically reached naked-eye levels already. It's now an easy target to find with binoculars, showing up as a distinct hazy ball.

And if comet Lovejoy continues its current course of brightening, astronomers say it may even plateau at magnitude 4.1 in mid-January, which would make it just barely visible to the unaided eye viewing it from light-polluted city suburbs.

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Time to break out those shiny new binoculars and telescopes and take a gander at comet Lovejoy hanging low in the late-night southeastern sky.


As of December 21, comet-watchers using large binoculars under dark skies were reporting on an online comet-observing forum seeing a hint of a very faint tail sweeping about 5 to 6 degrees back from the comet's coma, the hazy cloud around the main body—that's about equal to ten full moon disks side-by-side in the sky. To see comet Lovejoy's path in the sky, check out this nice printable finder chart.

To spot the tail yourself, you'll first want to try using averted vision, an observing technique using peripheral vision to bring out details in a faint object. But hopes are that the sky show will get easier to see throughout the holiday period into the New Year.

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This sky chart shows comet Lovejoy parked next to the globular cluster M79 (also shown in telescope view) on the night of December 28, 2014.


See for Yourself

During Christmas week, the best way to glimpse the comet is using binoculars as it travels through the low southern constellation Columba, the Dove, about 30 degrees south of the constellation Orion.

Wait until late night, near or after local midnight, for the comet to rise in the southeastern sky and away from the hazy horizon. Helping your hunt around Christmas Day, it should be passing some 18 degrees to the lower right of the brightest star in the sky, Sirius. That separation in the sky is equal to the width of two fists side-by-side.

Also not to be missed, as comet Lovejoy continues to climb higher in the northern sky it will offer a pretty photo opportunity. On December 28 and 29 it will be posing with the stunning globular star cluster Messier 79 in the constellation Lepus, the Rabbit. Amazing to think that this city of stars lies approximately 40,000 light-years from Earth, compared with comet Lovejoy's 4.4 light-minutes distance.

Stay tuned for more updates in the New Year.

Happy hunting!

Follow Andrew Fazekas, the Night Sky Guy, on Twitter, Facebook, and his website.

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