December 2013 Night Sky Newsletter

This month’s claim to fame are two significant meteor showers, the Geminids and the Quadrantids.  Both of these showers are considered major meteor shower events.  With all the excitement of the November comet show, with the disintegration of Comet ISON and a pleasant surprise with Comet Lovejoy, observers may now return to the more expected surprises in the winter night sky.  The main focus of course is staying warm enough to enjoy it.  With the cold crisp skies come the winter constellations just full of some of the brightest 1st magnitude stars.  The reader is referred to the December 2012 Newsletter which describes these in more detail, as well as planets and Deep Sky Objects.  All the StarscapeScientific Newsletters can be located on the Newsletter Archives tab in the left navigational column.

DECEMBER GEMINIDS

The Geminid meteor shower is one of the best of the entire year, with upwards to 120 meteors per hour normally.  This year the shower expectation will be lower due to the Full Moon which falls on the 17th, with the actual peak of the meteor shower during a bright gibbous phase on the 13th and 14th.  Nonetheless, the Geminids are typically very bright and can leave long trails lasting up to several seconds to minutes.  They are known to produce the occasional fireball.  You can expect to see 20 to over 40 per hour due to the moonlight washing out the fainter ones.  Probably the best time to view will be in the predawn hours of the 14th or at least after late-night of the 13th.  By then the bright moon will be lowering to the west.  The actual radiant of the shower is in the direction of the constellation Gemini, just 3 degrees from the bright star Castor.  Gemini rises in the east just before midnight, and high nearly overhead by 3:30am in the North America mid-latitudes.  Also placed in the constellation Gemini is the bright planet Jupiter, which outshines everything in the sky except the moon.

So dress warmly, bring a blanket and jug of cocoa or coffee and a lounge chair.  Binoculars are nice but you won’t need them or a telescope, unless you wish to view the moons and cloud bands of Jupiter while your up. Remember, meteors can be seen in nearly every portion of the sky, not just in the direction of the radiant.  The radiant is just the point in the sky from which they seem to originate.  The actual origin of the dust cloud producing the Geminids is believed to be from the asteroid Phaethon, generally considered as a former comet.  At some time in the distant past, the comet lost icy volatile material and may have been captured by Jupiter’s gravity.

The Quadrantids occur almost at the end of December into their peak on January 3rd 2014, being the first major meteor shower of 2014.  They will be discussed in a following newsletter.  The show in 2012 was outstanding.

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