How to get started tonight 40 photos, plus how-to in the hobby of astronomy imaging details Welcome to

Astronomyby Robert Burnham

Bring astronomy to your backyard Start naked-eye observing How to choose a telescope

Take a virtual sky tour

© 2011 Kalmbach Publishing Co. This materialA maysupplement not be reproduced into any Astronomy form magazine www.astronomy.com  618089 without permission from the publisher. www.Astronomy.com Naked-eyeastronomy

DARYL POWELL

COVER PHOTO: LARRY LANDOLFI; MARS IMAGE: STSCI

very clear evening when the Sun sets, the Little Bear. The Dipper’s stars likewise the sky darkens and the stars come out. form part of Ursa Major the Great Bear. EAs our local piece of planet Earth turns If you don’t see any bears, don’t worry. away from the Sun and daytime fades into Constellations are invented patterns that night, we look out toward the universe. began as pictures in the sky to help early peo- The simplest way to discover the stars ple remember important myths and legends. is to begin as the earliest observers began, Some constellations, such as spring’s Leo using just your own two eyes. If this evening the Lion, summer’s Scorpius the Scorpion, is clear, why not step outside and spot a few and winter’s Taurus the Bull, are prehistoric. star patterns? The backyard offers conve- They first appear in ancient Mesopotamian nience, while a local park or schoolyard may records at the dawn of history. Others provide a view of the sky less cluttered by were invented more recently to gather stars trees or buildings. unclaimed by earlier constellations. Today, Ancient skywatchers had a big advantage 88 constellations cover the sky with no over- over us. Their skies were dark. Today, count- laps or gaps between them. ALASKAN AURORA. Years of less lights from streets, parking lots, vehicles, To learn them properly, check out high solar activity often produce and buildings brighten the skies over subur- Astronomy magazine. Every month, it pub- displays of the aurora borealis, or ban locations. But even so, the brightest stars lishes beautiful, easy-to-use color sky maps northern lights. (24mm lens at still shine through. showing the stars and planets visible to the f/2, Fuji 800 Superia film; taken eye. It also showcases all the month’s sky March 19, 2001) MICHAEL J. O’LEARY Getting oriented events, so you’ll miss nothing. Under the night sky, take a look around. Can With Polaris identifying north, turn and ICY BEAUTY. The famed Pleia- you find the Big Dipper in the north? It may look southward. If it’s winter, you may see des cluster (M45) is a lovely sight be high in the sky and upside down, or lower MILKY WAY. A wide-angle view takes in in binoculars. (Astro-Physics 6- toward the horizon. It’s a bit longer than lots of sky and a meteor. Such views are inch f/7 telescope, composite your hand at arm’s length with the fingers easy to find away from city lights. (16mm image on Kodak PPF ISO 400 film, spread. The two outer stars in the “bowl” lens at f/4, tripod-mounted, 10-minute 45-minute exposure) ALLEN HWANG point toward Polaris, the North Star. Polaris exposure, Fuji NHG II 800 film) DOUG ZUBENEL is part of a constellation called Ursa Minor COMET IKEYAZHANG. Bright comets are Naked-eye rare, but when they appear, a naked-eye view is often the most satisfying. (300mm lens at f/2.8, Fuji 800 film, 5-minute expo- astronomy sure taken April 14, 2002) ANTHONY GALVAN III

the tall figure of Orion the Hunter, his feet bright and reddish-orange. Jupiter, col- ⁄⁄⁄ VIEWING AN ECLIPSE scraping the bare trees and rooftops. In ored white, usually shines even brighter. spring, the figure will be Leo, whose shape Saturn, dimmer than Jupiter, looks ivory- clearly resembles a crouching feline. On white. The outermost planets — Uranus, A total solar eclipse is one of nature’s most summer nights, the southern sky is dominat- Neptune, and Pluto — glow weakly and awe-inspiring events — and a spectacle no ed by Scorpius the Scorpion, and higher up, belong in telescope territory. onlooker ever forgets. The Moon slowly Cygnus the Swan. In autumn, the main fig- Far outshining any planet is the Moon, turns broad daylight into night as it glides ure overhead is the Great Square of Pegasus its face darkly mottled with lava flows. in front of the Sun, blotting it from view. At the Flying Horse. To learn constellations, The Moon circles Earth, keeping one side mid-eclipse, the Sun vanishes, but its outer use a sky map to locate the major figure for turned toward us. It first appears as a thin atmosphere — the corona — surrounds the the appropriate season. Then, let that figure’s crescent in the evening sky. Night by night, blackened Moon like an exotic flower. stars guide you to fainter constellations. the lit portion grows. The half-lit point Total solar eclipses occur because the is called First Quarter because the Moon Moon happens to be just big enough to Starlight, star bright has completed one-fourth of its monthly cover the Sun as seen from Earth. During You’ll notice immediately that stars dif- orbit. At Full Moon, it is completely lit and every New Moon, the Earth, Moon, and Sun COPPER MOON. You can observe total fer in brightness. Astronomers rank stars ThisTWILIGHT seasonal TRIO. movement A crescent reflects Moon, Earth’s Venus, floods Earth with reflected sunlight. After line up approximately. But an eclipse results eclipses of the Moon easily with just on a magnitude scale that originated with yearlyand travelMars (lowerin its orbitright) around stand together the Sun. in Full Moon, the lit portion shrinks. When only when the alignment is exact, which your eyes. (10-inch Meade LX-200 the evening sky on May 14, 2002. (Nikon happens just once or twice a year. ancient Greek skywatchers. They ranked No one notices the sky changing from Last Quarter Moon arrives, we see it in Schmidt-Cassegrain telescope at f/10, Coolpix 995 digital camera) FRED ESPENAK the brightest stars as first magnitude and one night to the next. Yet any given star rises daytime morning hours as well as at night. Because the path of totality created by six-image mosaic taken with an SBIG the dimmest as sixth magnitude. All others about 4 minutes earlier each evening due to After passing Last Quarter, the Moon the Moon’s shadow is narrow and can fall ST-8 CCD camera) DARYL POWELL lay in between. Astronomers now use deci- Earth’s orbital motion. Four minutes differ- shrinks to a crescent visible shortly before anywhere on Earth, your chances are low mals to note small steps in brightness, and ence per day means that after a month, stars sunrise. Then it reappears low in the west for seeing a total eclipse in any given place. and lasts several hours. If skies are clear, even employ negative magnitudes for bright rise 2 hours earlier and set 2 hours sooner. after sunset, and the cycle begins anew. So it’s no wonder that many eclipse-tour anybody on Earth’s night side can follow objects. For example, Sirius in Canis Major Thus, constellations slowly drift westward companies have sprung up, making it easy the eclipse’s progress using their naked the Great Dog shines at magnitude –1.4. The throughout the year. Be prepared for a dedicated eclipse-chaser to make a eyes, binoculars, or a telescope. trick to keep in mind is that a larger magni- Star-watching is easy, but a few basic thrilling “journey into darkness.” As the Moon glides into total eclipse, it tude number means a dimmer star. Wandering stars preparations make it a lot more comfort- Lunar eclipses typically occur at Full turns reddish-copper in color. This occurs Every star has a magnitude, but only a Planets don’t reappear regularly each season able. Depending on the season, you may Moon before or after a solar eclipse because the shadow is faintly lit by sunlight few hundred stars have names. Many star the way stars do because planets constantly want long underwear and a ski cap — or because that’s when the Moon is most filtered through Earth’s atmosphere. It’s the names come from their place in the con- orbit the Sun, just as Earth does. Yet planets insect repellent. Buy or make a dim red- likely to pass through Earth’s shadow. A light of all the world’s sunrises and sunsets stellation as described by the ancients. For always are found somewhere along a band of lensed astronomer’s flashlight for reading lunar eclipse is easy to see, safe to look at, falling on the Moon at once. example, Rigel, which marks Orion’s left constellations that straddles an imaginary line charts. The red light keeps your eyes dark- knee, means “left leg of the giant” in Arabic. called the ecliptic — Earth’s orbit projected adapted. Take a lawn chair and a thermos (Why Arabic? Because antiquity’s astronomy onto the stars. Because all planets have orbital filled with hot cocoa or tea. came to Europe in the Middle Ages through planes close to Earth’s, their positions don’t If you have binoculars, bring them Arabic translations.) vary much from the ecliptic. That’s why you along. But learning your way around the Each hour, stars move westward about as see the ecliptic plotted on star maps. sky goes better if you start with no optical far as your fist held at arm’s length with the Two planets, Mercury and Venus, orbit aid at all. Constellation patterns are easiest thumb extended. If you look north, figures closer to the Sun than Earth. You will see to find with the wide-field view your eyes like the Big Dipper or Cassiopeia the Queen them only before sunrise or after sunset. alone can provide. Newcomers to astrono- creep around Polaris like the hands of a Mercury in particular is hard to spot, being my often feel overwhelmed at the array of giant clock running backward. Besides this often low in the twilight. (Binoculars help.) telescopes and accessories in magazine ads daily motion due to Earth’s rotation, the con- Venus, however, can blaze so brightly people and reviews. How can you possibly choose stellations also slip westward as weeks pass. frequently mistake it for a UFO. among them? Where do you even start? The outer planets (which lie farther from Relax. The telescope market has a lot of LOOKING NORTH. Stars trail as Earth rotates. the Sun than Earth) move slowly among the variety, but choosing a scope is simpler SUN FLOWER. During a total solar eclipse, the Sun’s pearly corona frames the Moon Polaris is the short, bright trail at top center. stars, with changes becoming apparent only than it seems. The goal here is to help you like flower petals. Special image-processing has revealed details in the corona visible (24mm lens at f/2.8, tripod-mounted, Fuji after a few weeks. Typically, they remain sort through the different kinds. And to the eye but difficult to capture on film. MARGE AND ROLAND CHRISTEN Astia 100 film, 4-hour exposure) JOSHUA VAUGHN visible for months. Mars often appears because the market is changing all the

www.astronomy.com  CHECK OUT A SCOPE. A good way to look through different kinds of telescopes under real observing conditions is to visit Choosing a a star party. Many of these get-togethers telescope take place every year. FRANK ZULLO

time, keep an eye on the ads and equipment reviews in Astronomy to stay up-to-date.

It’s all done with mirrors A telescope’s purpose is to gather and focus light. To do this, optics either reflect light or refract (bend) it. In a reflecting telescope, mirrors form the image. In the common Newtonian design (invented by Sir Isaac), a curved mirror sits at the bottom of an open-ended tube. Light enters the tube and reflects from the mirror, converging to a focus. Before it reaches focus, a flat mirror directs the light through GOTO POWER. Computer-controlled a hole in the tube’s side into a focusing mounts make it easier for beginners to device. The focuser holds a high-quality find objects — and they help even experi- QUALITY REFRACTOR. A well-made refractor on a sturdy alt-azimuth mounting has several magnifying glass called an eyepiece. By enced observers spend less time search- strong points: It is highly portable, easy to use, and gives super views. ASTRONOMY: WILLIAM ZUBACK changing the eyepiece, you change the mag- ing and more time viewing. MAGGIE MCKEE nification of the telescope. Reflectors, like all telescopes, are speci- DREAM SETUP. Home observatories reflect an owner’s style of skywatching. This one, with for public sky-viewing on the sidewalks of fied by aperture (the diameter of the main a big Dobsonian-mounted reflector, uses a roll-off roof for whole-sky access. DAVE KRIEGE San Francisco.) It pivots from side to side mirror) and focal ratio, abbreviated as f- and swings up and down — the hallmark of ratio. The f-ratio is the focal length — the provide the most light-gathering ability for take on a car trip far from city lights will an altitude-azimuth, or alt-az, mounting. distance from the main mirror to the focus the price and are easy to use. Their optics reveal unforgettable wonders. You keep sky objects in view by moving the point — divided by the aperture. Thus a 6- require occasional tweaking to keep in But even at home, size and convenience telescope by hand. It’s easier than it sounds; inch reflector with a 48-inch focal length is alignment (called collimation), but this matter. Use this rule of thumb: The best most people quickly get the hang of it. an f/8 telescope. Focal ratios for reflectors takes only a minute or two. telescope to own is one you’ll use often. If A sophisticated variation is the popular run from about f/4 to f/10 or larger. Those Reflectors range in size from about setup is time-consuming, or if the scope is (and pricier) go-to mounting. This has with small f-ratios have wide fields of view 4-inches aperture to behemoths with mir- difficult to transport, you’ll use it less. motors to drive the telescope under com- and are good for sweeping through star rors 3 feet across. Big ones reveal faint gal- Holding it steady puter control. Most also contain a list of sky fields at low power. Larger f-ratios are often axies and nebulae that smaller scopes can’t Optics are only half the telescope; the other objects stored in memory. chosen for planetary viewing, where a wide show. Small reflectors, however, make good half is the mounting. The least expensive The last kind of mounting is the equato- field of view matters less. first telescopes because you can handle and mounting is the Dobsonian, named for John rial, which lets you follow the sky with a EQUATORIAL REFRACTOR. An equatorial SOLID STABILITY. Top-quality refractors Reflectors are deservedly popular. They transport them easily. A telescope you can Dobson, who popularized it. (He devised it single motion, often using a small electric mounting lets the telescope follow the are highly capable instruments, so a solid

motor. Equatorial mountings are more com- stars with a single motion. MAGGIE MCKEE mounting makes sense. MAGGIE MCKEE plex than an alt-az and, accordingly, cost more. They also require careful setup. How- Refractors range in size from 2.4 inches (60 f-ratios make good travel scopes. ever, for sky photography, an equatorial millimeters) upward. Refractor optics come in two kinds, the mount is essential, and having one certainly Inexpensive refractors have earned a achromat and the apochromat. Both seek to makes visual observations easier. bad reputation over the years thanks to correct the spurious color that single lenses low-quality models sold in some discount create when light passes through. (Briefly, Bending light stores and on TV shopping channels. Avoid an uncorrected lens acts like a weak prism Refracting telescopes are what most people these. (A tipoff is advertising that stresses and puts false-color halos around bright think of when you say “backyard telescope.” magnification, such as “See 800x!!”) objects.) An achromatic lens couples two Light passes through a lens at the telescope’s A well-made refractor is a delight to use. lens elements to cancel nearly all extra front and converges to a focus at the back. As The closed tube makes for an essentially color, while an apochromat uses more ele- BIG DOB. Dobsonian-mounted reflectors BIGGER DOB. Really big Dobs pull in lots TRACK THE SKY. Equatorial mountings with a reflector, you change eyepieces to maintenance-free telescope that’s ready to ments, special glass, or both to cancel out have revolutionized astronomy by offer- of light. Fortunately for owners, they dis- make viewing easier and are a must for change magnification. Focal ratios go as low go at a moment’s notice. Because of their all spurious color.

ing big apertures at low cost. MAGGIE MCKEE assemble for transport. MARK DAHMKE astrophotography. MAGGIE MCKEE as f/4, but most refractors use f/6 or longer. small size, the 3- to 5-inch models with low Is the high-price apochromat worth

 ⁄⁄⁄ welcome to astronomy www.astronomy.com  STARLIGHT HOTEL. A new trend in Choosing a backyard skygazing is to visit resorts located in dark-sky country. You can bring your own telescope and equip- telescope ment — or use a telescope that the resort provides. JOHN NEMY

GETTING IN DEEP. Really dedicated I SEE YOU. Some amateur astronomers LAST NIGHT’S SHOTS. Astrophotogra- skywatchers have setups far beyond transport observatory-quality tele- phers sometimes bring a computer what most beginners imagine. In cer- scopes and charge-coupled device and image-processing software with tain cases, that means building 20-inch (CCD) cameras to dark locations hop- them to star parties. This lets them Dobsonian-mounted binoculars. MARTY ing to capture elusive celestial prey work on images and share their results

CURRAN/MAGGIE MCKEE unseen from cities. MARTY CURRAN/MAGGIE MCKEE with others. MARTY CURRAN/MAGGIE MCKEE

ing ancestors. Telescopic astronomy began light and dark portions — where sunrise or show craterlets, landslides, and other geo- BIG EYE. This 14-inch f/11 Schmidt- PORTABILITY PLUS. Schmidt-Cassegrain telescopes (SCTs), like the 8-inch model pictured in 1609 when Galileo Galilei turned a sunset occurs. With no lunar atmosphere, logical details. Cassegrain folds a long focal length into above, rank as popular items in the small-telescope market. Besides high-quality optics small, crude telescope on the Moon, plan- grazing sunlight reveals the Moon’s fea- So it goes, night by night, through the

a stubby tube. MAGGIE MCKEE and good portability, most feature go-to mounts. KENNETH D. WHEAT ets, and stars — and opened a doorway tures with starkness and clarity. month. Features such as the Moon’s “seas” into the universe. The adventure begins with a slender — vast lava floods that fill shallow impact the extra money? For an experienced goes up to a secondary mirror attached to Research your telescope purchase thor- Moon in the western sky after sunset. Aim basins — appear with mountains rimming backyard astronomer or astrophotogra- the corrector, and travels back down the oughly, and set a realistic budget. If it’s Exploring the lunar world your telescope, insert a low-power eyepiece pher, yes. But for most ordinary visual tube to pass through a hole in the main under $300, wait to save more or perhaps The first celestial object anyone with a tele- — and sprawled before you lies a stunning FINE GLASS. High-quality eyepieces uses, a good achromat works fine. mirror to the focuser and eyepiece. purchase 7x50 or 10x50 binoculars. Resist scope looks at is the Moon. Nothing else is wilderness of craters. are key to getting the best views through Refractors often are sold with equatorial This “straight-through” optical-path effi- those $99 refractors — their low quality will as bright (except the Sun), reveals so many The same time on the following night, a telescope. MAGGIE MCKEE mountings. Some models also offer quality ciently folds a long focal length into a short sour your whole astronomy experience. details, or is so easy to explore. the Moon stands higher above the western alt-az mountings, and go-to versions are tube. Such a design makes even large mod- One source for advice is a local astron- The best way to see lunar features is to horizon and its sunrise line falls farther gaining in popularity. The mounting on an els smaller than you’d guess by their f- omy club. A better idea is to visit one of observe the terrain lying close to the ter- from its edge. Features that were inky entry-level refractor often gives unsteady ratios, which average f/10. the star parties held all over North Amer- minator — the line that divides the Moon’s pools of darkness last night now views. A sturdy mounting is well worth SCTs and Maks (as they are known) ica each year, mostly from spring through paying extra for. High-quality equatorial range from 2.8 inches (70mm) to 16 inches fall. (See Astronomy.com’s listings.) At a mountings can cost as much as the optics, (406mm) in aperture. You’ll find them eas- star party, you can look through many especially with motor drives and controls. ily portable in sizes under 8 inches, and different telescopes under a real sky. For astrophotography, however, an excellent they’re highly versatile. While suitable for Starting simple is a good idea. Fine equatorial mounting is essential. viewing any target, they excel when pointed starter scopes include a 6-inch Newtonian at small objects (like planets) seen best at reflector, a 2.4- to 4-inch refractor, or a Hybrid optics higher magnifications. 3.5- to 5-inch catadioptric. A third kind of telescope uses a lens and Most SCTs and Mak telescopes have alt- These instruments will introduce you to mirrors — the catadioptric, or compound azimuth mountings (with or without a go- the many wonders of astronomy. Each of telescope. Two main designs dominate: to drive). With the addition of an accessory them can show you the Moon and planets, the Schmidt-Cassegrain and Maksutov- called a wedge, you can change the mount plus enough star clusters, nebulae, and gal- Cassegrain. (Manufacturers also produce to equatorial. The alt-azimuth arrangement axies to fill a lifetime’s exploring. Viewing LOOK HERE. A finder scope is an essen- HOLD STEADY. Astronomical bin- Schmidt- and Maksutov-Newtonian works well for most observing, however. the night sky with the unaided eye pro- tial “extra” for any telescope — and oculars can be heavy, and using scopes.) Light enters the tube through a vides memorable sights, but you aren’t installing a quality 8x50 model is a them is easier with a parallelogram corrector lens, bounces off a main mirror, Making the choice much better off than our earliest skywatch- good upgrade. MAGGIE MCKEE mounting. MAGGIE MCKEE

 ⁄⁄⁄ welcome to astronomy www.astronomy.com  SEEING DOUBLE. Between Cassiopeia and the center of Perseus lies the Double Cluster (NGC 869 and NGC Sky 884), a beautiful sight in binoculars. (Takahashi 9-inch, tour Kodak Gold 400 film, 45 minutes at f/3.9) PHILLIPPE DURVILLE

their margins. Some have shoreline craters, monthly illustration in Astronomy.) internal heat. For reasons no one yet partly melted down and buried under old Saturn is a smaller, lighter, cooler understands, sunspot numbers wax and lava flows. Others show infinite variations Jupiter, so its cloud bands are less pro- wane over an 11-year cycle. in light and dark, especially as the phase nounced — but the prominent ring sys- approaches Full Moon. tem makes a world of difference. Saturn The starry sky Every lunar explorer discovers favor- never fails to elicit a gasp when people see Scanning the sky — and particularly the ites — the crater Copernicus, the Alpine it for the first time. You’ll want to look at Milky Way — with a telescope, you find Valley, or the tangled terrain of the ancient its jewel-like beauty all night long. stars in pairs and triplets. Some are chance southern highlands. You’ll watch them groupings, but most are real multi-star change shape and form as sunlight plays The Red Planet systems, locked together by gravity. While across the landscape. Your telescope lets No one has yet stood on the sands of Mars, they orbit at high speeds, their distances MOON SHOW. Jovian moon Io passes in you become a lunar astronaut, walking in but you can peer into a backyard telescope are so great that decades or centuries will front of Jupiter, casting its shadow on the imagination across dusty plains and look- and sometimes see hazy clouds over its pass before changes become apparent. giant planet’s softly tinted cloud tops. ing over yawning craters. large volcanoes. Occasionally, dust storms Stars also gather in clusters — tight, (Astro-Physics 7-inch at f/9, Sony cam- gather to veil parts of Mars — or all of it. rich groups that stand out from the back- corder video frame) DAVID HANON Beyond the Moon Polar caps grow and shrink as seasons pass. ground. Open clusters contain a few dozen All the planets are fair game for backyard Mars is a challenging world to observe to a few thousand members. The Pleiades telescopes — even distant Pluto. But the from Earth because of its small size and (M45) in Taurus is a beautiful open cluster, most popular are Jupiter, Saturn, and Mars varying distance — it’s close to Earth for more populous and less scattered than its because they show the most features. only 2 months out of 26. Yet, in many ways, neighbor, the Hyades. Jupiter spins in less than 10 hours, so Mars is our most earthlike neighbor. This Stars also group together as globular the vista changes all the time. What looks exerts an irresistible pull on every backyard clusters. If open clusters are like small like a cloud-striped surface on Jupiter is telescope owner. towns, globulars are entire cities, contain- the top of a deep hydrogen atmosphere ing tens of thousands to upward of a mil- churned by heat from below. Spots and The Sun lion stars each. When you look at a globu- markings appear, last for months or years, Before leaving the solar system, take a look lar through a telescope, you see a bright then merge and disappear. The Great Red at its central star — the Sun. Solar viewing core region sprinkled with stars that run Spot, twice the size of Earth, has lingered requires a special solar filter that fits over outward until the blackness of space takes STAR CITY. Globular cluster M13 in Her- for more than 300 years. Jupiter-watchers the front of the telescope — never use an over. A globular cluster looks like a tiny cules contains hundreds of thousands of monitor the planet for changes, and alert eyepiece solar filter. A front-mounted solar pile of sugar dropped on black velvet. stars. (20-inch RC Optical Systems tele- scientists when they occur. filter lets you safely view features such as The best place to look for open clusters scope, SBIG ST-10XME CCD camera, Around Jupiter, a family of moons sunspots, which are relatively cool and is along the Milky Way, but globulars are three-image composite) TOM BASH AND JOHN FOX/ swirls like a miniature solar system. Galileo dark regions far bigger than Earth. They usually found flanking it. The region of sky ADAM BLOCK/NOAO/AURA/NSF discovered the biggest four, which you can occur where the Sun’s magnetic field richest in globular clusters lies in Scorpius easily follow in any size telescope. (See the becomes knotted and hinders the flow of and Sagittarius, best seen in summer. But a superb globular, M13, lies in spring’s Hercules, where it shines bright enough to see by eye from a dark observing site. Star clusters are born from vast clouds of dust and gas — nature’s star factories — that occur throughout the Milky Way. Astronomers call such clouds nebulae, and they make favorite targets for tele- scope users. A nebula looks like a soft

BANG! Lunar crater SPIRAL GALAXY. NGC 7331 shows the FADING STAR. The Dumbbell Nebula NEIGHBOR GALAXY. You’ll barely see the Cassini measures 35 classic form: spiral arms, dust clouds, and took shape when an aging star threw off Andromeda Galaxy (M31) with your naked miles across and a disk with hot, blue stars. (14.5-inch shells of gas. (Meade LX-200 12-inch, Pic- eyes from a dark site. (14.5-inch reflector, more than half a Cassegrain, Kodak Royal Gold 200 film, tor 416XTE camera, color filter wheel, SBIG ST-10E CCD camera, four-part com- mile deep. LEO AERTS composite image) TONY AND DAPHNE HALLAS four-image composite) MIKE FULLER posite exposure) TONY AND DAPHNE HALLAS

www.astronomy.com  FACE TO FACE. Looking upon the face of M101, a spiral galaxy in Ursa Major the Great Bear, we see its bright starlike nucleus Sky and its curling arms traced by red nebulae tour and hot, young, blue-white stars. JAMES FOSTER

haze through the eyepiece. Irregular in Backyard astronomers who prowl for shape, many nebulae contain an open star galaxies are the deepest of the deep-sky cluster, born from the nebula perhaps explorers. As they peer into the telescope, in the last few million years. A famous they look back in time, deciphering light example is the Orion Nebula (M42). that took millions of years to arrive. Another kind of nebula is the planetary Quirks of geometry present some gal- nebula, so-called because through small axies edge-on, like pencil beams of light. telescopes many resemble Neptune. A Some have ragged edges. Others, tipped planetary nebula represents the end of a face-on, tantalize us with spiral arms that star’s life. As middleweight stars age, they hover on the edge of invisibility. A few blow off symmetrical shells of gas around galaxies show dark smudges like black eyes, RECYCLING PROGRAM. A supernova cre- their hot cores. The Dumbbell Nebula where dust lies thick and the star-making ated the Crab Nebula, and its expanding (M27) in Vulpecula the Fox is a favorite factories are running day and night. debris will help make new stars. (Centu- planetary. Not all stars die quietly, how- The Milky Way and Andromeda galax- rion 18.2-inch at f/2.8, SBIG ST-8E camera ever. The Crab Nebula (M1) in Taurus ies both belong to the Local Group, a clus- and color filter wheel) CLIFF WRIGHT marks where a star exploded about 1,000 ter of some 40 galaxies. Nearby in Virgo years ago. The remnant is expanding, lies a much larger galaxy cluster, one of shooting gaseous debris back into space, many millions that shape the framework where much of it will wind up in a new of the universe. Backyard astronomers can generation of stars. explore this realm in part — but even the pros haven’t sounded its depths. Realms of infinity You can take your first step beyond the Of space and time Milky Way just by using your naked When we turn from the realm of the galax- eyes. A dark autumn night shows the ies and look homeward, distances shrink, Andromeda Galaxy (M31) as a pale and the light our telescopes receive grows smudge of light near the Great Square younger. Globular clusters appear as they of Pegasus. M31 lies 2.5 million light- were perhaps 20,000 to 50,000 years ago. years away. A telescope shows off its And star clusters like the Pleiades shine as CRATERSCAPE. The shore of the Moon’s bright nucleus and lets you trace its they were hundreds to thousands of years Mare Nectaris shows craters and other fea- tightly wrapped spiral arms. And the ago. Light from the nearest star — Alpha tures in all states of preservation. DANIEL ETHIER Andromeda Galaxy is just the start; Centauri — takes 4.3 years to crawl from beyond lies a realm of galaxies you can there to here. Pluto orbits some 5 light- spend the rest of your life dis- hours away from the Sun, while Earth zips covering. around just 8 light-minutes from the Sun. And what about moonlight? It’s reflected sunlight that left the Moon’s dusty sur- face just 1.3 seconds ago. When you look through a telescope, you get more than a spaceship of the imagination — you get a time machine, too.

STAR FACTORY. Below Orion’s three- starred belt lies the Orion Nebula, a vast LORD OF THE RINGS. Saturn’s ring cloud of dust and gas where stars are system is one of the most breathtak- being made. (Takahashi 6-inch at f/3.3, ing sights backyard astronomy has to 40-minute exposure) JOHN CHUMACK offer. (Astro-Physics 7-inch f/9, Sony camcorder video frame) DAVID HANON

www.astronomy.com  Shooting

the sky CHRIS VENHAUS

With simple gear, you can produce go-to drive because the star field will rotate great photographs, or, with a digital cam- around the center of the photo. era, electronic images. Mount a camera Skyshooting’s major leaguers use the that can take time exposures on a tripod. telescope as the camera lens. This is more Set the focus to infinity, and open the challenging than it looks. You need top- aperture fully. Try exposures of 30 sec- notch equipment: a camera; a solid onds, 1 minute, 5 minutes, and so on. mount; accurate, automated tracking; (Keep notes.) Dark skies are a huge plus, and superb optics. You also need a T-ring well worth a trip away from streetlights. and T-adapter, two inexpensive accesso- Another technique lets you piggyback ries that let you connect the camera to your camera (with lens) to a telescope that the focuser. has a motor-driven equatorial mount. Be Shooting the sky is the ultimate goal for sure to attach the camera securely. The many just starting out in astronomy. It’s mount tracks the stars during the expo- only natural that, as you learn to identify sure. The result is a wide field of view with more celestial objects, you’ll want images OUR GALAXY RISING. A big telescope pinpoint stars all across the image. Try of them. And the sooner you get started looks toward the east as the Milky Way using different lenses. Caution: The tech- looking at the sky, the sooner you’ll have rises into view. TIM KIMBLER nique doesn’t work with an alt-azimuth amazing images to show your friends.

ECLIPSE SEQUENCE. March 3, 2007, brought the first total lunar eclipse in 21⁄2 years. The photographer used a Meade ETX-90EC telescope for this sequence. MIGUEL CLARO

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