The Sky This Week , November 25 – December 2, 2014 !

The Sky This Week, 2014 November 25 – December 2

Venus returns!

Jupiter, 2014 NOV 11, 10:28 UT

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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.

The Sky This Week, November 18 – 25, 2014 !

The Sky This Week, 2014 November 18 – 25

A Cornucopia of sky delights.

NGC 869 & 884, the Perseus Double Cluster Imaged 2013 August 15 at Fishers Island, New York 80-mm (3.1-inch) f/6 Antares Sentinel refractor with Canon EOS Rebel T2i DSLR

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The Moon may be found as a thin waning crescent in the pre-dawn sky as the week opens and returns to the evening sky as a waxing crescent as it ends.  New Moon occurs on the 22nd at 7:32 am Eastern Standard Time.  If you’re up early on the 19th you’ll see Luna just three degrees northwest of the bright star Spica.  On the evening of the 25th you’ll find the Moon in the southwestern sky northeast of ruddy Mars

The absence of the Moon finds us in the middle of the November observing campaign for the international “Globe At Night” campaign.  This global “citizen science” effort is dedicated to determining the effects of light pollution around the world, and it is very simple for anyone to participate.  This month the effort focuses on the constellation of Perseus, the Hero, which may be found high in the northeastern sky at around 9:00 pm.  If you face north at his time you’ll see the “W”-shaped constellation of Cassiopeia on the meridian; she’ll actually look a bit more like an “M”.  Perseus occupies the space just to the right of Cassiopeia and is centered on the second-magnitude star Mirfak.  I think of Perseus as resembling the “winner’s” portion of a wishbone, which seems quite appropriate for this time of year.  The top of the wishbone points back toward Cassiopeia, while the longer tine follows a gentle arc that will lead you to the Pleiades.  The shorter, upper tine ends in a most unusual star, Algol.  Its name derives from ancient Persian and means “the head of the demon”, and it represents an eye on the severed head of the Gorgon Medusa that Perseus dispatched in one of his many adventures.  The star is unusual in that its apparent brightness dims by over one magnitude every 2.87 days, as if it was slowly winking at us.  This was noticed by the classical Arab astronomers in the first millennium, who thus gave it a very descriptive name.  You should have little trouble in finding Mirfak and Algol from suburban skies, although Algol may be difficult when it is at a minimum.  To make a measurement for Globe At Night, compare your view to the online charts on the project’s website and add your data to the growing knowledge base.

Just below Perseus you’ll find a bright star that has a very distinctive golden tint.  This is Capella, the brightest star in the constellation of Auriga the Charioteer.  Capella’s name is derived from the Latin word for “goat”, and it represents Amalthea, the she-goat who nursed the infant Zeus as he was hidden from his father Cronus.  In one legend the young Zeus accidentally broke off one of the goat’s horns which then became the source of boundless nourishment, the Cornucopia.  Fittingly in our modern traditions Capella is close to the meridian at midnight when we take the time to celebrate the bounty and nourishment in our lives with the Thanksgiving feast.

The stars between Cassiopeia and Auriga lie in the foreground of the winter Milky Way, which you can faintly see from dark locations away from city lights.  This is a great area of the sky to patrol with binoculars; several bright star clusters lurk among the wafts of light.  The famous Perseus Double Cluster lies between the top of the Perseus “wishbone” and Cassiopeia and can be glimpsed on very clear nights from suburban back yards.  Three bright clusters may be found within the bounds of Auriga as well.  Try to spot them while the Moon is absent from the sky.

The early evening still finds ruddy Mars in the southwestern sky, still chugging eastward ahead of the Sun.  The red planet is now moving into the sparsely populated constellation of Capricornus and will be the brightest object in this part of the sky until he gets a visit from the Moon at the end of the week.  You will now need a large telescope and exceptionally steady air to see much of any details in his tiny pink-hued disc.

Jupiter now rises just before 11:00 pm EST, gradually making his way into the evening sky.  The best time to observe him, though, is still just before dawn when he crossed the meridian.  This is also the time of day when the atmosphere tends to be in its steadiest state, so telescopic detail can be surprisingly good.  To make sure you get the best possible view, though, leave your telescope out overnight so it can reach equilibrium with the air.  Removing your scope from the warmth of the house to the chill of the morning air will ruin your planned observations.

The Sky This Week, November 12 – 18, 2014 !

The Sky This Week, 2014 November 12 – 18

Looking for signs of winter.

Messier 45, The Pleiades star cluster Imaged 2013 November 30 from Great Meadow Field Event Center, Old Tavern, Virginia.

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The Moon spends the week passing through the stars of late winter and early spring adding her waning glow to the morning hours.  Last Quarter occurs on the 14th at 10:16 am Eastern Standard Time.  Look for the Moon rising with bright Jupiter shortly before midnight on the morning of the 14th.  The next morning you’ll find her perched just under five degrees south of the bright star Regulus in Leo.  By the week’s end she moves into the sparse starfields of western Virgo.

As the Moon deserts the evening sky and our first cold snap descends on Washington, we can see many harbingers of winter in the evening sky.  By 8:00 pm the stars of the Summer Triangle are hovering above the western horizon.  Most of the southern sky is dominated by what seems to be vast, empty space, dotted here and there with a few second- and third-magnitude stars, much like the few leaves that linger on the tree branches.  These stars form an otherwise obscure set of constellations that were known to the ancients as the “water signs” of the Zodiac.  Capricornus, Aquarius, and Pisces cover one quarter of the zodiacal band, but most of us in urban and suburban locations can barely see them.  Even from dark sites there are only a few handfuls of faint stars to delineate these figures, giving the sky a cold, empty appearance.  Turn to face the north, however, and a few familiar patterns call for your attention.  These are best exemplified by the W-shaped grouping that outlines Cassiopeia, the Queen, and the wishbone-shaped figure of Perseus, the Hero.  Both of these constellations lie in the plane of the Milky Way, and owners of binoculars and small telescopes can track down dozens of knots of light that resolve into star clusters.

By 10:00 pm the stars of the Great Winter Circle are above the eastern horizon, with the familiar figure of Orion the Hunter seemingly climbing one leg at a time into the night.  High in the east you’ll find the small knot of stars known as the Pleiades or the Seven Sisters.  Technically they are an asterism within the bounds of the constellation of Taurus, the Bull, but there is probably more lore and legend associated with these stars than any other grouping in all the heavens.  Seeing them rising during the first frosty nights of fall has always made me think of the coming winter, and they have been harbingers of fierce storms and heavy seas for mariners for millennia.  Virtually every culture that has marveled at the night sky has a story about these seven tightly grouped stars.  Even the Hobbits of J.R.R. Tolkien’s Middle Earth had a name for them, “Remmirath”, or “The Netted Stars”.  The Pleiades offer the urban stargazer a pleasant sight through binoculars.  Where our unaided eyes can see six or seven cluster members, binoculars will reveal nearly two dozen.  Each increase in aperture will gather in many more; large telescopes under dark skies show hundreds of members.

Back in the early evening sky we still find ruddy Mars clinging to the southwestern horizon during the hour after the end of evening twilight.  Mars is now passing through the setting stars of Sagittarius, starting the week just two degrees north of the constellation’s brightest star Nunki.  During the week he begins to climb northward on the ecliptic, setting his sights on the faint stars of Capricornus.

Jupiter now rises by around 11:30 pm EST, but he’s still best placed for viewing in the hours before dawn.  He crosses the meridian just before sunrise, fading as Old Sol brightens the morning.  This week if you’re up early you’ll find Old Jove entertaining the waning crescent Moon.  You’ll find ample photo opportunities as the Moon and Jupiter form interesting patterns with the bright nearby star Regulus.

Early in the week you may still capture a fleeting glimpse of the elusive planet Mercury along the southeastern horizon.  He’ll be about five degrees high half an hour before sunrise early in the week, but by the weekend he’ll be lost in solar glare.

The Sky This Week , November 4 – 11, 2014 !

The Sky This Week, 2014 November 4 – 11

Busy beavers and changing seasons

Waxing toward the Beaver Moon Lunar mosaic imaged with USNO’s 30.5-cm (12-inch) f/15 Clark/Saegmüller refractor 2014 November 4, 00:15 – 00:20 UT

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The Moon brightens the evening skies this week, waxing through the full phase as she climbs northward along the ecliptic to join winter’s rising constellations.  Full Moon occurs on the 6th at 5:23 pm Eastern Standard Time.  November’s Full Moon is popularly known as the Beaver Moon or Frosty Moon, both of which describe phenomena frequently seen at this time of the year.  This is generally the month when we see our first killing frost, and it is also a time of heightened activity for beavers as they work to shore up their dams and lay in food stocks to survive the coming winter.  Luna forms an attractive triangle with the orange-tinted star Aldebaran and the Pleiades star cluster on the evening of the 7th.  Over the next couple of nights she drifts through the heart of the Great Winter Circle.  On the 10th she may be found just east of the second-magnitude star Alhena in the constellation of Gemini.

The change back to Standard Time brings big changes to our skies each fall.  I happen to particularly notice this change in the mornings and late evenings.  I’ve never been a “morning person”, so getting up well before dawn has always been a struggle.  Now that we’re back on Standard Time, however, I typically rise just before the Sun to a brightening sky, which makes the process a little less painful.  The evening hours, however, are a bit more of a shock.  All of a sudden, it seems, the winter stars are here, and I now see Orion rising in the southeastern sky where just last week I saw the emptiness of the autumnal constellations.  I no longer have the Summer Triangle to look at after dinner, and the summer Milky Way is now vanishing during the prime observing hours.

However, in between the passing stars of summer and the rising stars of winter, there are sights to captivate the patient skywatcher.  Cooler nights generally bring clearer skies, and despite the season’s paucity of bright stars, the fall’s best sights are in prime position to enjoy.  The most easily recognized constellation at this time lies just to the north east of the zenith; it’s a group of five stars that form a “W”-shaped figure.  This is the constellation of Cassiopeia, who, along with her husband Cepheus, daughter Andromeda, a sea-monster named Cetus, and the hero Perseus and his fantastic flying horse Pegasus, act out one of the heavens’ oldest legends.  All of these characters are represented in the sky, but of them all Cassiopeia is the easiest to spot on a Moon-washed night.  Cassiopeia is a great place to prowl for Milky Way star clusters with binoculars and telescopes once the Moon leaves the vicinity.  If you look just south of the zenith at 9:00 pm you’ll see a large square made up of second-magnitude stars straddling the meridian.  This is the “Great Square” of Pegasus, an asterism that serves as a convenient guidepost to other constellations nearby.  The Great Square is also a great place to test the clarity and darkness of your observing site.  There are many faint stars within the square’s confines.  Most suburban skywatchers are lucky to see two stars near the northwest corner, but travel far from city lights on a moonless night and you may spot over a dozen!

Standard Time has shifted the viewing time for Mars into the very early evening.  He’s still visible low in the southwestern sky after sunset, but the best time to look for him is now around 6:00 pm.  This week he continues his eastward trek through the stars of the tea-pot asterism of Sagittarius, but if you wait until after dinner to see him you’ll be too late.  He now sets shortly after 8:00 pm.

Conversely, giant Jupiter gets a boost from Standard Time, and he now rises well before midnight.  The best time to see him is still before dawn, so you’ll need to rise at around 5:00 am to see him against a dark background sky, but this is usually when the atmosphere is very still, offering a great view of Old Jove through the telescope.  Jupiter’s Galilean moons will be putting on a good show for us this year since the Sun appears to pass through Jupiter’s orbital plane.  This will set up a series of mutual eclipses and occultations between the four bright moons throughout the coming apparition.

Finally, early risers have a great opportunity to see the elusive planet Mercury in the east as morning twilight begins to gather.  Mercury reaches greatest elongation from the Sun on the 1st and is now in the last week of his best morning apparition for the year.  You will find him in the company of the first-magnitude star Spica over the first few mornings of the week.  Mercury will appear brighter and a bit redder than the star.  The two slowly part company as the week passes.