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The Sky This Week, 2014 November 25 - December 2

Venus returns!
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Jupiter, 2014 NOV 11, 10:28 UT

The Moon wends her way through the evening skies this week, waxing from crescent to gibbous phase as she passes through the dim autumnal constellations.  First Quarter falls on the 29th at 5:06 am Eastern Standard Time.  Luna finds few bright companions to mingle with this week, but on the evening of the 26th she may be found just two degrees west of the third-magnitude star Dabih in the constellation of Capricornus, the Sea-Goat.  Look some 10 degrees to the southwest of the Moon on this evening to spot ruddy Mars.  On December 1st, use binoculars to find the distant planet Uranus less than half a degree south of the Moon.  Even though the planet only shines at sixth-magnitude, it will be the brightest object in this position with respect to the Moon’s disc.  If you observe the Moon before 7:00 pm that evening you will notice another sixth-magnitude star very close to the Moon’s northeast dark limb.  That star will disappear at 7:06 pm for observers in the Washington, DC area.

The brightening Moon further dims the already hard-to-find autumnal constellations.  One star in the autumn sky still stands out, though.  This is Fomalhaut, the brightest star in the constellation Pisces Austrinus, the Southern Fish.  It is sometimes referred to as “The Solitary One” for its lonely location over the southern horizon during the early evening hours at this time of year.  Fomalhaut is the 18th –brightest star in the sky and is the most isolated of all the first-magnitude stars.  Located at a distance of about 25 light-years its spectrum has been used for decades as a calibration source for measuring other stars.  It appears to be a relatively young star, and in 2008 an object thought to be a planet with three times the mass of Jupiter was found in an extensive dust shell that surrounds it.  This object, known as Fomalhaut b, is the first object of its kind to be imaged directly thanks to the sharp eye of the Hubble Space Telescope.

The late evening gives us a preview of the winter sky as Orion and his cohorts clamber over the eastern horizon.  By 10:30 pm the bright stars of the Great Winter Circle are all in view, ready to brighten the sky for the long winter nights.  Nine of the 25 brightest stars in the sky fill this region, colorful jewels in a setting of ebony darkness.  The most prominent of these is the star Capella, whose golden glow approaches the zenith at midnight.  As we mentioned last week, this star is indirectly associated with our celebration of Thanksgiving with its ties to the origin of the Cornucopia in mythology.  From a physical point of view Capella, like Fomalhaut, is more than it appears.  It is actually a four-star system consisting of two pairs.  The first pair makes up the star that we see and consists of two yellow giant stars in a close orbit with a period of 104 days.  The second pair is made up of two red dwarf stars that orbit the more massive pair in 388 years.

Go out shortly after sunset to welcome bright Venus back into the evening sky.  You’ll need a low southwestern horizon to glimpse her since she sets just half an hour after the Sun.  She will gradually work her way higher in the sky, setting well over an hour after Old Sol by Christmas.

Mars continues to keep pace with the Sun, setting at 8:13 pm EST each night this week.  You can find him near the Moon on the evening of the 26th, then watch him march resolutely toward the dim stars of Capricornus.  Mars will continue his eastward trek through the end of the year and will linger in the early evening sky well into 2015.

Giant Jupiter rises four minutes earlier each night, and by the end of the week you’ll find him in the eastern sky at around 10:30 pm.  He is slowly drifting eastward between the faint stars of Cancer and the head of Leo, the Lion.  He is best placed for viewing in the pre-dawn hours when he crosses the meridian at around 5:15 am.  If you’re up by 6:00 am you’ll still have an hour to enjoy him before he disappears in morning twilight.

 

 

 

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