Using our sky maps.
Can you spot Orion? The Pleiades? The Big Dipper? The first step into amateur astronomy is learning the stars in your evening sky. Once you know them, they'll be your companions for life.
And they will be the framework for finding everything fainter that you can hunt out with binoculars or a telescope.
Starting on the next two pages are 13 big, round sky maps, for the evenings of each month from December 2014 through December 2015.
First, find the right map for your time and date. Start with the page labeled for the current month, and check the dates and times in the top-left corner of the page.
Within an hour or so of the time listed for your date, take the map outside. Bring a red-light flashlight to read it by. Dim red light won't spoil your night vision.
Once outside, you need to know which direction you're looking. (If you're unsure, just remember where the Sun sets--that's roughly west.) Now look at the yellow direction labels around the map's edge. Turn the map around so the label for the direction you're facing is right-side up, like "Facing NE" in the example at right. That edge of the map is the horizon in front of you. The stars above it will match the stars you're facing.
The farther from the map's edge that stars are plotted, the higher they'll be in your sky. The map's center is your zenith, directly overhead. Ignore all the parts of the map above horizons you're not facing.
The Moon is plotted at selected phases in the evening sky. The planets are shown where they are at the middle of the month.
Lower left of the map is a scale showing the magnitudes (brightnesses) of the stars. Each map shows stars as faint as 4th magnitude--about as dim as you can see through typical suburban light pollution.
Into the Night
Let's try this with the map labeled "January" (page 21). Turn it around and hold it so its southeast horizon (labeled "Facing SE") is level. Nearly halfway from there to the center you'll find the constellation Orion--with bright orange Betelgeuse in one shoulder, bluish-white Rigel marking his upraised foot, and the three-star Belt of Orion in between. Go outside around the right time, face southeast, and look about halfway up the sky. There's Orion!
The maps (and smaller sky scenes) are drawn for a skywatcher near 40[degrees] north latitude (for example, New York or Denver). But they can be used throughout the north temperate latitudes. (If you're far south of 40[degrees], stars in the southern part of the sky will appear higher than on the maps, and stars in the north will be lower. If you're far north of 40[degrees], the reverse will be true.)
Two tips: Look for the bright stars and patterns first; the faint ones are often difficult to see. Also, constellations look a lot bigger in the sky than here on paper!
Greek Letters on Star Maps
Many stars in most constellations are named with lower-case Greek letters. The brightest star is sometimes named Alpha, the first letter in the Greek alphabet.
[alpha] Alpha [beta] Beta [gamma] Gamma [delta] Delta [epsilon] Epsilon [zeta] Zeta [eta] Eta [theta] Theta [iota] Iota [kappa] Kappa [lambda] Lambda [mu] Mu [??] Nu [xi] Xi [omicron] Omicron [pi] Pi [rho] Rho [sigma] Sigma [tau] Tau [upsilon] Upsilon [phi] Phi [chi] Chi [psi] Psi [omega] Omega
CHECK out this VIDEO: SkyandTelescope.com/maptutorial
MOON PHASES Full Moon 5 Last Quarter 14 New Moon 21 First Quarter 28
December 2014 * Winter's Starry Approach
The first of winter's spectacles are now climbing the eastern sky.
EARLY EVENINGS in December are a time of celestial anticipation, with the bright constellations of winter beginning to make their appearance.
The earliest forerunners are already high. Turn the map around so the horizon labeled "Facing North" reads right-side up. High in the north--nearly at the center of the map--is Cassiopeia, a bright zigzag of five stars like a flattened letter M. Outdoors in the dark, face north and look high overhead. There's Cassiopeia, always a landmark of fall and winter.
Turn toward the right to face northeast, turn the map accordingly, and look lower. One brilliant star shines in that direction: Capella, the Goat Star, the leading light of Auriga, the Charioteer. We've connected the dots on the map so you can recognize his big, blocky head--with a pointed hat on the left, a blunt nose facing up, and Capella shining as his bright eye.
Between Cassiopeia and Auriga, and a bit to the right, is Perseus, legendary rescuer of Andromeda. The way we've connected his dots, he's reaching out to take hold of Andromeda's foot. He too has a pointy hat, much smaller than Auriga's.
Between Perseus's hat-top and Cassiopeia is plotted the glorious Perseus Double Cluster. It's an enhanced patch of Milky Way to the naked eye on a dark night, a pair of slightly speckly fuzz-patches in binoculars, and two glorious spangle-swarms in a telescope used at low power.
Turn the map farther around so the "Facing East" horizon is level at the bottom, and you'll see that one foot of Perseus points to the peerless Pleiades or Seven Sisters star cluster.
Below the Pleiades is orange Aldebaran with the faint stars of the big, loose Hyades cluster above it and to its right. Aldebaran is the 1st-magnitude eye of Taurus, the Bull. The full Moon shines near it on December 5th.
And rising majestically beneath Taurus is grand Orion, the Hunter.
Planets in December 2014
Mercury begins an interesting evening apparition at the end of December. Look for it a little below bright Venus: just above the southwest horizon as twilight fades.
Venus is beginning to appear very low in the afterglow of sunset. It becomes more apparent during the course of December, a little above the southwest horizon a half hour or less after sunset. Mercury will stand very close to it for several days around January 10, 2015.
Mars remains in good view in the southwest during and after twilight. Don't confuse it with Fomalhaut far to its left, nearly south. Mars will remain near its present spot at dusk for most of the winter.
Jupiter, in Leo, rises in late evening with Regulus below it. It will reach its next opposition on February 6, 2015.
Saturn is now a morning planet, glowing low in the southeast as dawn begins to brighten. On the morning of December 19th look for it hanging below the waning crescent Moon.
The Geminid meteor shower, often the richest of the year, should peak on the night of December 13-14. In 2014 the sky is dark that night until the last-quarter Moon rises around midnight. You might see an average of about one meteor per minute from 9 or 10 p.m. until dawn.
MOON PHASES Full Moon 4 Last Quarter 13 New Moon 20 First Quarter 26
January * Brilliance in the January Dark
The coldest month brings the brightest stars.
ANY TIME OF YEAR is good for learning your way around the stars and constellations --for getting acquainted with the cosmos beyond Earth, as it appears to human eyes, from your own backyard. Bui winter is an especially fine time.
True, January can be terribly cold. But by coincidence, winter's icy evenings offer some of the most spectacularly brilliant constellations of any season. (And there are no mosquitoes.)
Look southeast on a clear dark night, at about the time listed for our all-sky map on the facing page (see the times and dates in its upper left corner). This view may get you permanently hooked on astronomy. The sky in that direction is alive with bright star patterns from the horizon on up.
For the next few paragraphs, try following along on the map. First, turn the map around a bit so that its southeast horizon is level at the bottom. Look for the yellow "Facing SE" on the edge.
Midway up the sky from there is Orion. Look almost midway from the SE horizon to the overhead point: the zenith, at the map's center. Orion's starry torso and legs are set off jauntily by his belt of three stars in a little diagonal row.
Above Orion is Taurus, the Bull. His V-shaped face is formed by bright orange Aldebaran and the fainter stars of the big, loose Hyades cluster.
Your gaze can follow bunches and sprays of stars up from Taurus to the top of the sky. The bright little Pleiades cluster is above Taurus's main pattern. Perseus is at the zenith (overhead).
Blocky Auriga is upper left from Taurus. It looks like a head seen in profile with a tall cap, and the bright star Capella serves as its eye. These two constellations are linked together by Beta ([beta]) Tauri, the brighter of the two stars marking the Bull's horn tips.
Quite low under Orion in the southeast is Canis Major, the Big Dog. Low it may be, but it's topped by the heavens' brightest stellar jewel: Sirius, the Dog Star. The dog wears it proudly on his chest. Only his front part has risen at the time of the map; his hindquarters and tail are still below the horizon.
In the east, well to the left and a bit higher than Sirius's shimmering brightness, shines the Little Dog Star, Procyon. It's not as brilliant as Sirius but is still easy to spot even through a light-polluted city sky. Procyon is the only bright star of little Canis Minor.
Planets in January
Venus and Mercury put on an interesting paired performance low in the afterglow of sunset. As January gets under way, keep watch with binoculars barely above the southwest horizon in bright twilight. Within a few days Venus makes its appearance --with faint little Mercury right next to it! Each day they become higher and easier. Soon you won't need the binoculars.
They appear less than 1[degrees] apart from January 8th through 12th. Then they separate. For the rest of the month Venus climbs higher in the twilight, while Mercury fades and drops back down.
Little Mars watches this twilight drama from their upper left. Mars is far from Earth now, on the far side of the Sun, so it's very modest in brightness. Its yellow-orange color always helps identify it.
Jupiter, in Leo, rises above the east-northeast horizon in midevening, and it shines higher in the east as night grows late. Below it by about a fist-width at arm's length is Regulus, the forefoot of Leo.
Saturn, in Scorpius, glows in the southeast before and during dawn.
MOON PHASES Full Moon 3 Last Quarter 12 New Moon 18 First Quarter 25
February * Two Dogs Follow Orion
The Hunter strides high across the south, leading his companions.
LAST MONTH WE HAD to wait until fairly late to see Orion at his highest in the south. But in February he arrives there soon after dark.
To Orion's lower left leaps Canis Major: a hound of heaven with brilliant, flashy Sirius at his heart. Higher to the left of Orion shines lesser Procyon in Canis Minor. These two stars form the big, equilateral Winter Triangle with Betelgeuse in Orion's shoulder, as shown in the photo below.
Binoculars or a telescope can help you search out some magnificent deep-sky wonders among these winter constellations. Just below the Belt of Orion is the dim, near-vertical line of Orion's Sword (only one star of which shows on the map at right). The slightest optical aid will reveal a small patch of hazy glow surrounding one of the Sword's middle stars. The glow is M42, the Great Orion Nebula, one of the brightest of the luminous hydrogen clouds in which new stars and planetary systems are being born. It glows pink in most photos, but our night-vision eyes respond differently to dim light than camera sensors do, so visually the nebula looks gray with a hint of green.
Binoculars can also reveal lovely little star clusters, such as M41 just a few degrees below Sirius. Look for labeled star clusters on the map, and with binoculars look for tiny, dim, ghostly-gray cotton puffs among the faint stars at the precise locations plotted.
Elsewhere in the sky, Deneb is finally about to set in the northwest. Well to Deneb's left, the Great Square of Pegasus is getting low almost due west.
Cassiopeia is high in the northwest but slowly moving lower. The Big Dipper is still rather low in the northeast but climbing.
Planets in February
Mercury emerges into dawn view by February 10th to 15th. Look for it just above the east-southeast horizon as daybreak gets under way. Binoculars help. The thin waning crescent Moon hangs to Mercury's left on the morning of the 17th. Mercury remains very low for the rest of the month.
Venus is the bright "Evening Star" in twilight; look west-northwest. It begins February low and moves higher each week.
Mars, much fainter, begins February not far (10[degrees]) to Venus's upper left. Watch Venus move up toward Mars each day and pass it on February 20th (by just 3/4[degrees]).
Jupiter, at the Leo-Cancer border, comes to opposition (opposite the Sun) on February 6th. So for the first half of the month it rises around sunset, shines in the east to southeast during evening, and is highest by midnight. Each week Jupiter climbs to the same height a half hour earlier.
Saturn rises after midnight and shines in the south-southeast before dawn. It's in northern Scorpius, above Antares and just above the nearly vertical row of stars marking Scorpius's head.
MOON PHASES Full Moon 5 Last Quarter 13 New Moon 20 First Quarter 27
March * Spring Pushes Winter Stars West
Going, going, but not yet gone are the constellations of winter evenings.
ORION, TAURUS, AND PERSEUS are still about halfway up the western heavens at the time of our map on the facing page. In the south, Canis Major is past its peak, but Sirius and the Big Dog's lesser stars still draw lots of attention.
Almost twice as high above Sirius (depending on your latitude), and perhaps a bit left, shines Procyon in Canis Minor. High above Procyon beam the two brightest stars of Gemini: Castor and Pollux, nearly overhead--nearly at the center of the map.
So much for the winter half of the March sky. Turn around to the east. High in the east-southeast is Leo, the Lion, in the vanguard of the spring constellations that are taking over the entire eastern sky. Leo boasts 1st-magnitude Regulus, in his forefoot as we've drawn the constellation on the map. Below Leo is big, dim Virgo.
About midway between Regulus and Pollux shines bright Jupiter. It's in a dim but important constellation: Cancer, the Crab. A few degrees to the right or upper right of Jupiter is Cancer's dim star cluster M44. In a dark sky it's visible to the naked eye as a faint, fuzzy patch of gray glow. Binoculars reveal a swarm of stars here, earning M44 its nickname: the Beehive.
High in the northeast, the Big Dipper is reaching its overarching springtime height. Examine the middle star of its handle, Mizar. Can you see its faint companion star Alcor, just barely to its lower left? If you have trouble seeing Alcor, using binoculars will make it easy.
Meanwhile, an amazingly bright star has just risen in the east-northeast. This is Arcturus, the "Spring Star," which will soon come to dominate the eastern sky.
Planets in March
Mercury is hidden deep in the sunrise.
Venus grows more eye-catching in evening twilight each week, blazing clear bright white higher and higher in the west at nightfall.
Look for faint Mars to the lower right of Venus. Each week now Mars becomes lower and harder to see.
Jupiter, in Cancer not far from the Beehive, shines brightly in the east at nightfall and higher in the southeast to south as evening grows late.
Saturn, in northernmost Scorpius, rises around the middle of the night and shines in the southeast to south in the early morning hours. Look below it for twinkly orange Antares.
MOON PHASES Full Moon 4 Last Quarter 12 New Moon 18 First Quarter 25
April * The Shifting Sky of Early Spring
The mild stars of springtime are now taking over the heavens.
AT THE TIMES for which our map on the facing page is drawn, the last constellations of winter are settling downward in the western third of the sky. Soon they'll be gone.
Turn the map around so the horizon labeled "Facing West" is level. Canis Minor, Gemini, and Auriga are still fairly high. But you need to look ever sooner after dusk to catch a last, low look at Canis Major, Orion, and Taurus.
The rest of the sky is filling with the dimmer but often intricate and storied constellations of spring. And spring's brightest two constellations, Leo and Ursa Major, have climbed to nearly their highest vantage points.
North is the way to face to find Ursa Major, the Great Bear. Turn the map around to put its northeast ("NE") horizon at the bottom and look very high, almost overhead (almost to the center of the map). There you can't help but notice Ursa Major's brightest part: the Big Dipper. The Dipper is currently turning upside down, with its handle to the lower right and its bowl to the upper left.
Now turn around to face south, and turn the map so its "Facing South" horizon is level. Leo stands very high in the south, not far from overhead.
Leo's forefoot star, Regulus, is also the handle end of a hook pattern known as the Sickle. The top of the Sickle marks Leo's head and mane.
A long, right triangle of brightish stars off to the left (east) of the Sickle forms Leo's hindquarters and tail.
Arcturus now rules the east. Lesser Spica, the sole bright star in Virgo, is about three fists at arm's length to Arcturus's lower right, in the southeast.
And to the right of Spica flies the distinctive, four-star sail pattern of Corvus, the Crow.
ECLIPSE OF THE MOON
On Saturday morning April 4th, the Moon will pass through Earth's shadow while visible from western North America. The eclipse will be partial from 3:13 to 6:45 a.m. Pacific Daylight Time, and just barely total briefly: from 4:56 to 5:04 a.m. PDT. (Change the times to your time zone.) Full details will be in the April Sky & Telescope and at SkyandTelescope.com.
Planets in April
Mercury comes into good evening view in the last week of April, low in the west-northwest as sunset fades. Look for it far to the lower right of Venus.
Venus shines brightly ever higher in the west during and after dusk. On April 11th and 12th Venus passes 2[degrees] to 3[degrees] left of Pleiades, a lovely scene in late twilight! Around April 19th Venus passes 7[degrees] north (upper right) of Aldebaran.
Mars is faint and ever lower in the sunset. On April 22nd, use binoculars or a wide-field telescope to try to catch Mars in conjunction with much-brighter Mercury; it's 1.3[degrees] to Mercury's lower left. Look for them low in the west-northwest about 30 to 45 minutes after sunset.
Jupiter, in Cancer, shines high in the south in twilight, and is second only to Venus in brightness. As evening grows late, Jupiter sinks lower in the southwest, then the west.
Saturn, at the head of Scorpius, rises in the southeast in late evening. It shines in the south before the beginning of dawn, with Antares to its lower left.
MOON PHASES Full Moon 3 Last Quarter 11 New Moon 17 First Quarter 25
May * Galaxies and Double Stars
Springtime specializes in certain types of telescopic targets.
MAY IS A MONTH of abundance by day: flowers bursting, birds hatching, sunshine and temperate breezes, new greenery all around. At first glance, the sky on May evenings looks like the opposite. Fewer naked-eye stars shine in the evening than in any other month (because the Milky Way is lying down all around the horizon).
For telescope users, however, May offers a generosity of double stars, galaxy fields unmatched at any other time of year, and the first of summer's swarming globular star clusters.
First things first. Venus grabs the eye in the west at nightfall among the last departing winter constellations. Jupiter blazes high to Venus's upper right. As for stars, Arcturus, Spica, and Regulus dominate the high heavens.
The edges of the sky have their bright points too. Procyon, Pollux, Castor, and Capella are fairly low in the west to northwest; Vega and Deneb are in the northeast; Saturn and Antares rise in the southeast. Find them on the facing-page map.
Not quite so bright is the Big Dipper, very high in the north. Follow the arc of the Big Dipper's handle out to Arcturus, then drive a spike (a straight line) down to Spica, then continue the curve to Corvus.
All the way from Corvus to the Big Dipper extends a wonderland of faint galaxies. Hundreds are detectable in a 6- or 8-inch telescope in a fairly dark, unpolluted sky --if you have a detailed sky atlas pinpointing the exact location of each one among faint stars. And, if you know how to use such a map with a telescope! There are tricks to this; see page 12 or the illustrated version at SkyandTelescope.com/charts.
For smaller telescopes or more polluted skies, nice double stars abound in the Big Dipper, Virgo, Canes Venatici, and especially Bootes. And some of the great globular star clusters of late spring and early summer are now on display, such as M13 and M92 in Hercules, M3 in Bootes, and M5 in Serpens. These clusters are plotted on the map (with symbols much larger and brighter, of course, than the objects actually appear).
With a good telescope, a large-scale star atlas showing lots of detail (such as the Pocket Sky Atlas or the bigger Sky Atlas 2000.0), and a deep-sky guidebook (such as Sue French's Deep-Sky Wonders, which includes its own charts), you can keep busy here through a lifetime of spring nights.
Planets in May
Mercury has its best evening apparition of the year from late April through early May. Look for it to the lower right of Venus about an hour after sunset.
Venus shines highest this month. It's the brightest evening "star" lighting the western sky during and after twilight. It begins May between the horns of Taurus and ends the month in line with Castor and Pollux in Gemini.
Mars is finally disappearing down into the sunset.
Jupiter is second only to Venus for brilliance. It's high to Venus's upper left, shining in dim Cancer near Leo. Watch Jupiter and Venus closing in on each other week by week.
Saturn glows in the southeast at nightfall, with equally bright Antares well below it. They climb to shine highest in the south around midnight. Saturn comes to opposition on the night of May 22nd.
MOON PHASES Full Moon 2 Last Quarter 9 New Moon 16 First Quarter 24
June * Stars of the Shortest Nights
Vega pins the top of the Summer Triangle to the high eastern sky.
WHEN DARKNESS FINALLY descends after the long, slow evenings of June, you can't help but notice Vega high in the east. Turn the map around so its "Facing East" horizon is level. Go out, face east, and look more than halfway from the horizon to overhead. Vega is the brightest star there.
Down to Vega's lower left, on the map and in the sky, is Deneb in Cygnus, the Swan. Much farther to Vega's lower right is Altair in Aquila, the Eagle. These three stars make up the huge Summer Triangle, now on the rise. In a dark sky you'll see the Milky Way running across the Summer Triangle horizontally.
Turn to face south, and turn the map back around accordingly. The brightest star very high in this direction around map time is yellow-orange Arcturus in Bootes, the Cowherd. Arcturus is so bright that many people glance over the rest of Bootes too quickly. But try tracing out the entire pattern. Its brightest stars form a long, slightly bent kite shape with Arcturus at the bottom where the tail is tied on. Or maybe you prefer to see Bootes as a long, pointed slipper, with Arcturus at the toe. To mismatch Greek and English: Bootes the Boot!
Just east (left) of the Cowherd's long form is a faint semicircle of stars. In ancient times this was sometimes seen as a sickle in his hand; apparently he harvested grain while herding his cows. Latei it became a separate constellation: Corona Borealis, the Northern Crown, honoring the tiara of the mythological lady Ariadne
The Alpha star of Corona Borealis, noticeably brighter than the rest, is named Alphecca (from an Arabic word referring to a broken circle) or Gemma (from Latin, referring to its position as a jewel in the crown).
On the opposite side of Bootes from Corona Borealis, another lady is honored by a constellation: Coma Berenices. It represents the shorn hair of a real historical figure: Queen Berenice II of Egypt, who reigned from 247 to 221 B.C. and sacrificed her hair in prayer for her husband's safe return from war. The constellation is a large, tousled group of faint naked-eye stars: the Coma star cluster, visible as a dim swarm if your sky is nice and dark.
You can pick out constellations of two giant humans, Ophiuchus and Hercules, in the southeast and east with the map's help, star by star.
High in the north (turn the map around so "Facing North" is down), Draco, the Dragon, arches over the faint, upright Little Dipper. The end star of the Little Dipper's handle, directly under its bowl at map time, is Polaris, the North Star.
Planets in June
Mercury is hidden low in the sunrise.
Venus and Jupiter shine in the west during and after dusk, the two brightest celestial objects after the Sun and Moon. Venus is the brighter one. Watch them close in on each other! They begin June 20[degrees] apart (two fists at arm's length) and come to a spectacularly close conjunction on June 30th. That evening they'll be just 1/3[degrees] degree apart (for North America), about the width of a chopstick held at arm's length. They'll fit together in a telescope's field of view. Mark your calendar.
Mars is now hidden behind the glare of the Sun.
Saturn glows low in the southeast at dusk and reaches its highest stand in the south after midnight daylight saving time. The star just lower left of it is Beta Scorpii, the top of the nearly vertical row marking the head of Scorpius.
Your latitude on Earth very nearly equals the height of Polaris (in degrees) above your north horizon--all night, all year.
MOON PHASES Full Moon 1 Last Quarter 8 New Moon 15 First Quarter 23 Full Moon 31
July * Scorpius Rampant
July brings the brightest summer constellation into grand early-evening view.
A FORMIDABLE STACK of beasts and heroes now lies along the meridian, the imaginary line dividing the sky into its east and west halves. The meridian runs from the south point on the horizon up through the zenith and down to the north horizon. Scanning up from the south to overhead, we see Scorpius, the gigantic Scorpion; Ophiuchus, the Serpent-Holder and healer; and Hercules, legendary conqueror of monsters.
High in the north (turn the map so its north horizon is at the bottom), under the feet of Hercules, we find the head of Draco, the giant Dragon, with his nose pointing at bright Vega. Just under Draco in the north is Ursa Minor, the Little Bear, a.k.a. the Little Dipper.
Of all these meridional constellations, Scorpius is the brightest. And this year it's crowned by the planet Saturn. But its low altitude in the south means that its bottom stars are dimmed somewhat by Earth's atmosphere, if you can see them at all.
How high you see Scorpius depends, of course, on your latitude. All our maps that show horizons are drawn for latitude 40[degrees] north (near New York City and Denver, for instance). Canadian observers will find that the lower parts of Scorpius don't even clear their horizon. In the southern U.S., on the other hand, you'll see Scorpius higher than it's shown on the map.
The main pattern of Scorpius is shaped somewhat like a long S toppling forward. To its right in the south-southwest is dimmer Libra, the Scales, whose stars were once seen as Scorpius's claws. The Scorpion's heart is marked by orange-red Antares, one of the most strongly colored bright stars. But Saturn on top is brightest of all.
Scorpius's low tail contains an impressive pair of stars: Lambda (A) and Upsilon (u) Scorpii, known as the Cat's Eyes. To their upper left are two impressive clusters, M6 and M7, visible in binoculars and even to the naked eye under dark conditions.
Above Scorpius, huge Ophiuchus separates the two parts of Serpens, the Snake: Serpens Caput ("head") and Serpens Cauda ("tail"). Serpens is the only constellation that's divided into two parts.
Ophiuchus's top star, marking his head, is fairly bright: Rasalhague, Alpha ([alpha]) Ophiuchi. Near it is the dimmer head of Hercules, Alpha Herculis or Rasalgethi--a fine telescopic double star that sometimes varies in brightness from season to season. Can you see its orange tint with the naked eye? The color is obvious in binoculars.
The items of greatest observational interest in high-flying Hercules, however, are in his Keystone pattern of four stars, the grand globular cluster M13 in the Keystone's western side, and the globular M92 farther to the north.
Draco's compact head consists of 2nd-, 3rd-, and 4th-magnitude stars. Draco seems to be eyeing brilliant Vega, the "sapphire of summer."
Planets in July
Mercury and Mars are hidden in the glare of the Sun.
Venus and Jupiter begin July still spectacularly close, low in the western twilight, after their conjunction on June 30th. Watch them slowly pull apart during July as they descend toward the sunset horizon.
Saturn is the planet of the dark evening, shining in the south to the upper right of Antares and the head of Scorpius.
MOON PHASES Last Quarter 7 New Moon 14 First Quarter 22 Full Moon 29
August * Late Summer Splendor
When Vega is overhead, the Milky Way's rich mid-region is on best display in the south.
AS OUR SKY MAP this month shows, August evenings are a time to enjoy bright Vega crossing the zenith and the glorious region of the Sagittarius Milky Way, rich in deep-sky objects, reaching its culmination in the south.
Vega is the queen star of high summer, tinted with a trace of blue like a sparkling speck of ice. Its color, of course, comes not from cold but extreme heat; think of blue-white arc-welding rather than ice!
Vega is the brightest star that ever passes straight overhead for the populous 40[degrees] latitude line around the Earth (for instance, New York or Denver). Lying in a sleeping bag on a summer night, you might wonder if it would fall on you.
Whenever Vega is overhead, gaze south and you're looking into the great mass of star clouds, nebulae, and clusters in Sagittarius, the direction toward our Milky Way Galaxy's center.
Vega is the high apex of the big Summer Triangle asterism, which it forms with Deneb and Altair. Vega is also part of a little gem of a constellation: Lyra, the Lyre. The ancient lyre was a harplike instrument, and this one is usually said to represent the one belonging to Orpheus, greatest of musicians in Greek myth.
A close look shows the 4th-magnitude star Epsilon ([epsilon]) Lyrae near Vega. This is a double star, as you can see with even the smallest binoculars. In a telescope at 100 power or more on a night of good seeing, each of the two components is splittable again, making this a quadruple star.
Just as famous is the object marked M57 on our map. This is Lyra's tiny Ring Nebula, a fluorescing gas cloud ejected by a dying star. In a medium-size to large telescope, it looks like a dim little smoke ring hiding among the faint pinpoints.
The brightest stars of Sagittarius form an asterism called the Teapot. Near the top of the Teapot is the globular cluster M22, majestic in telescopes. Puffing out of the spout is the Large Sagittarius Star Cloud (not drawn on the map), a bright piece of Milky Way that more or less marks the direction toward our galaxy's center. The galactic center itself is four times farther than the star cloud's distance of 7,000 light-years; it's hidden behind opaque clouds of dust.
Up from the spout come a plethora of pufflike nebulae--the Lagoon (M8), Trifid (M20), Omega (M17), and Eagle (M16). Higher shines the naked-eye Scutum Star Cloud with its telescopic wonder, the M11 open cluster.
Away from the Milky Way, Arcturus remains the brightest star in the west. And low in the east the Great Square of Pegasus, symbol of autumn, is already lofting up into early view.
Planets in August
Mercury, Venus, Mars, and Jupiter are all hard or impossible to see this month, hiding near our line of sight toward the Sun and beyond.
That leaves Saturn as the lone bright planet of August. Look for it starting to move lower into the southwest now at dusk. Once you've found Saturn, look for Antares sparkling to its left or lower left by roughly a fist at arm's length. They'll both sink into the sunset come fall.
JUDGING LIGHT POLLUTION
The most reliable way to judge the darkness of your sky is by the richness and detail, or lack of it, visible in any given stretch of the Milky Way.
PERSEID METEOR SHOWER
The sky is free of moonlight for the Perseid meteors this year. The peak of the display should be from about 11 p.m. your local time August 12th to dawn on the 13th. But the shower is active to a lesser degree earlier in the evening, and for many days before and after. See page 50 for more.
MOON PHASES Last Quarter 5 New Moon 15 First Quarter 20 Full Moon 27
September * The Zenith Birds of the Equinox
Three constellation birds fly nearly straight overhead as summer turns to fall.
AFTER THE HAZY DAYS of high summer, September brings some of the clearest nights of the year to much of North America. On such an evening in a dark rural area when the Moon is down, the Milky Way is a vast, mottled band of dreamlike glow arching high across the sky, from the north-northeast to the south-southwest. Its position is shown by the lighter band across the map on the facing page.
Light pollution dims or kills it. But even in urban areas where the Milky Way is completely invisible, the brilliant stars of the big Summer Triangle, which frames a prominent portion of it, are easy to spot.
The Summer Triangle is currently overhead: in other words, at the map's center. Vega is its brightest star, and Vega's constellation Lyra (discussed in last month's essay) used to be not a musical instrument but a vulture.
Altair is the second-brightest star of the Triangle. It's the highlight of Aquila, the Eagle. The ancient Arabs saw Vega and Altair as the Diving Eagle and the Soaring Eagle, respectively, using the two dim stars close to each one as the wings. Epsilon and Zeta Lyrae make a V with Vega like a diving bird of prey. Beta and Gamma Aquilae are almost in line with Altair, like the wings of a gliding bird. These patterns look much more realistic to me than the traditional Greco-Roman constellations here.
Altair is the closest first-magnitude star of summer, only 17 light-years from Earth. Between it and the neck of big Cygnus, the Swan, look for little Sagitta, the Arrow.
The third Summer Triangle star is Deneb, marking the tail of Cygnus, a realistic swan even in its classical form. Remarkably, Deneb is nearly 100 times farther away than Altair: roughly 1,500 light-years. It's a rare supergiant star; if Deneb were as close to us as Altair is, it would shine almost as bright as the first-quarter Moon!
The brightest stars of Cygnus form the Northern Cross; Deneb marks the cross's head. The shaft of the cross, or the neck of the Swan, runs along the Cygnus Star Cloud, a particularly rich area of the Milky Way. Even through a fair amount of light pollution, binoculars resolve these swarms into a wondrous wealth of faint specks.
Planets in September
Mercury remains deep in the sunset.
Venus is fast coming into good view in the east at dawn. Look an hour before sunrise, and you'll see it climbing higher into better view week by week.
Mars glows dimly to the left of Venus during the first week of September, then lower left of it for the rest of the month.
Jupiter joins the eastern dawn array around mid-September. Look for it well to the lower left of Venus and Mars as dawn begins to brighten.
Saturn remains in the southwest at dusk, with Antares to its left. They're moving lower every week.
Uranus, in Pisces, and Neptune, in Aquarius, are well up in the southeast and south by late evening. For these you'll need optical aid; they're magnitude 6 and 8, respectively. With binoculars or a telescope, use the finder charts for them at SkyandTelescope.com/urnep.
MOON PHASES Last Quarter 4 New Moon 12 First Quarter 20 Full Moon 27
October * The Dim Autumn Zodiac
Three faint but famous constellations span the south.
THE CONSTELLATIONS of autumn have a reputation for dimness. This doesn't hold true everywhere in the autumn sky, but it does across the south, where we now look at the dimmest stretch of the zodiac: the big, indistinct constellations Capricornus, Aquarius, and Pisces.
The zodiac is the band of 12 constellations around the celestial sphere where the Sun, Moon, and planets spend most of their time (because the solar system is a flat plane, more or less). Capricornus, Aquarius, and Pisces make up about a quarter of the zodiac's sky-circling span.
Despite their dimness, they do have their attractions--in addition to currently hosting dim Uranus (in Pisces), Neptune (in Aquarius), and the waxing Moon from October 21st through 26th. If you have even a moderately dark sky, you can use the map to piece out their patterns star by star. Just remember that the real patterns will appear much larger than here on paper.
Two landmark asterisms (star patterns that aren't full constellations) are here. One is the dim Circlet of Pisces, labeled on the map. The other is the Water Jar of Aquarius, which includes the sideways pattern of stars just left of Alpha ([alpha]) Aquarii. The way we've drawn Aquarius, the Water Jar is his head seen in profile; he's running and carrying a spilling bucket.
Far below the head of Aquarius twinkles an exception to the southern-dimness rule: lonely 1st-magnitude Fomalhaut.
Capricornus, due south on the map, contains two wide double stars for binoculars on its western (right-hand) end: Alpha ([alpha]) and Beta ([beta]) Capricorni. With sharp vision, you can resolve Alpha Capricorni into a tight pair with your unaided eyes.
Elsewhere on October evenings, Deneb in Cygnus passes nearly straight overhead for many of our readers. The big Summer Triangle of Deneb, Vega, and Altair extends west from there.
Higher in the southeast to east are Pegasus and Andromeda. They lead the eye onward to Cassiopeia and Perseus, in the east to northeast.
Planets in October
Mercury emerges low in the sunrise around October 7th, far to the lower left of Venus and Jupiter. Look for it there for nearly the rest of the month.
Venus, Mars, and Jupiter put on quite a show before and during dawn. They start the month with Venus, the brightest, high in the east in early dawn, Jupiter far to its lower left, and much fainter Mars and Regulus more or less in between. The three planets move closer together and then pass each other day by day, as shown in the series of scenes on the facing page.
Saturn continues drifting lower in the southwest at dusk. Twinkly Antares stays about a fist at arm's length to its left.
Uranus, in Pisces, and Neptune, in Aquarius, are in the southeast and south during evening awaiting your binoculars or telescope. You'll need to use the finder charts at SkyandTelescope.com/urnep.
MOON PHASES Last Quarter 3 New Moon 11 First Quarter 18 Full Moon 25
November * Andromeda's Dramatic Family
One Greek myth binds six constellations covering much of the autumn sky.
EXAMINE THE ALL-SKY map on the facing page. Almost at the center of the map (i.e. straight overhead) is the Great Square of Pegasus. The Great Square is supposed to be the body of the famous winged horse of Greek legend. If you're facing south, Pegasus seems to be flying upside down, with his long neck reaching westward (to the right). His nose is the 2nd-magnitude star Epsilon ([epsilon]) Pegasi, named Enif.
The Great Square includes a star from a neighboring constellation, Andromeda, as its northeast corner. That star, Alpha ([alpha]) Andromedae (also known as Alpheratz), forms one end of a line of three 2ndmagnitude gems marking the long body of Andromeda, damsel in distress in one of the best-known Greek stories.
Cassiopeia, Andromeda's mother, is a major sky landmark. Her five brightest stars form a flattened M shape very high in the north on November evenings. (Turn the map around so its "Facing North" horizon is level.)
Much dimmer than Cassiopeia the Queen is nearby Cepheus the King, Andromeda's father. He's at Cassiopeia's left as you face north. Below them is Polaris, the North Star.
Andromeda's rescuer is Perseus, a hero memorialized in a striking constellation now ascending the northeast to Cassiopeia's lower right. In the story he rides in on Pegasus, but in the sky they're rather far apart.
Below Perseus in the northeast is the bright star Capella and its constellation Auriga, the Charioteer, who has no part in the tale despite his proximity to the characters in the sky.
Turn the map back around so its "Facing South" horizon is down. Not very high in the south shines Fomalhaut. Way off to its left in the southeast swims big Cetus, the Whale or Sea Monster, which was sent to devour Andromeda until Perseus snatched her up and carried her off on his flying steed.
On another, unrelated side of the sky, we're not yet done with summer. Face west; the Summer Triangle of Deneb, Vega, and Altair is still more than halfway up from the horizon to the zenith.
Now face due east; the Hyades and Pleiades star clusters, in the shape of a dim, sideways V and a tiny dipper, are low but on their way up, heralding bright winter stars to come.
Planets in November
Mercury is out of sight in the glare of the Sun this month.
Venus, Mars, and Jupiter still shine high together in the dawn as November begins. Jupiter is on top. Brilliant Venus passes faint little Mars on the 3rd, then for the rest of November all three lengthen out in a diagonal line, as shown on the facing page.
Saturn is still spottable in evening twilight as November begins; look just above the west-southwest horizon. But Saturn moves lower every day and soon disappears for the season. Don't expect a sharp telescopic view of any planet so low!
Uranus, in Pisces, and Neptune, in Aquarius, are high in the southeast to south during evening, glowing below naked-eye visibility at 6th and 8th magnitude, respectively. Hunt them out with binoculars or a telescope using the finder charts at SkyandTelescope.com/urnep.
MOON PHASES Last Quarter 3 New Moon 11 First Quarter 18 Full Moon 25
December * Winter Skies Arise
The end of fall and the start of winter bring big celestial changes.
WITH WINTER'S APPROACH in early December, and then its official arrival on the night of December 21-22, 2015, wintry Orion rises in all his glory onto our evening all-sky map. Look for him low in the east-southeast. Orion is certainly the eye-catcher when you face this direction at map time.
But if you look in other directions, you'll see other marvels too.
Look low in the west and you can't miss Altair, the eye of Aquila, the Eagle--whose talons are lost in the horizon mists where this celestial bird finally seems to be coming to roost.
Altair almost seems separated now from its brothers, Vega and Deneb, the other bird-stars of the Summer Triangle (see page 36). Those are over in the west-northwest. The highest of them is Deneb. It's like the jewel on the handle of a big sword or dagger, the Northern Cross in Cygnus, that falls down to the northwest horizon during the course of the evening.
Look low in the south and southeast and you see ... nothing. Or almost nothing. Lonely Fomalhaut shines on the right of this dim region. Moderately bright Diphda or Beta ([beta]) Ceti, in the bottom of Cetus, the Whale, is just above this area and well to Fomalhaut's upper left. Count yourself lucky if you have a dark enough sky to see more stars in this region.
Look due north (turn the map around so its north horizon is down) and you'll probably notice 2nd-magnitude Polaris, which is serving as the North Star during our era of human history.
Lift your eyes way, way up from Polaris and you can't miss the zigzag of Cassiopeia, the Queen, almost overhead.
But now face east again (turn the map around so its "Facing East" horizon is level). Here we see a wide fountain of bright constellations spraying up from the area of Orion and, to Orion's left, Gemini. Above Orion is Taurus, highlighted by the Pleiades cluster and orange Aldebaran, the bull's eye star. Above Gemini is Auriga, bearing bright Capella.
And high above Capella is Perseus, with its famous variable star Algol, and slightly brighter Alpha ([alpha]) Persei, the brightest of a large, loose group of young stars known as the Alpha Persei Association. Most of these stars aren't quite bright enough to make it onto the map, but they show gorgeously in the photo above. Compare the photo with Perseus and its surroundings on the map.
Planets in December 2015
Mercury begins showing itself very low in the southwestern twilight around the middle of December 2015. By Christmas it's somewhat higher and easier to see.
Venus shines brightly in the southeast before and during dawn, moderately low now. On December 7th in the daytime, the waning crescent Moon in a blue sky occults (covers) Venus for parts of North and Central America. See the December 2015 Sky & Telescope for details.
Mars, in Virgo, glows to the upper right of Venus before and during dawn. Late in the month it passes by Spica, which is just a trace brighter. Compare the blue-white of Spica with the yellow-orange of Mars.
Jupiter, near the Leo-Virgo border, rises in the east around the middle of the night and shines high in the south (far upper right of Mars) by early dawn.
Uranus and Neptune, in Pisces and Aquarius respectively, are high in the south in early evening. At 6th and 8th magnitude they need binoculars or a telescope and good finder charts, such as those at SkyandTelescope.com/urnep.
THE GEMINID METEOR SHOWER
The sky is moonless for the best hours of this year's Geminid meteor shower. It should peak on the nights of December 13-14 and 14-15. From 9 or 10 p.m. until dawn, you may see a meteor per minute on average if your sky is clear and dark. Bundle up! The shower is less active for a couple nights before and after. See page 50.
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|Title Annotation:||astronomical observations|
|Date:||Jan 1, 2015|
|Previous Article:||Celestial highlights of 2015.|
|Next Article:||Exploring the moon.|