Sky & Telescope May 2010

Big Binos vs. Small Scopes: Which to Buy for What Use

p. 34

THE ESSENTIAL MAGAZINE OF ASTRONOMY

We Told You So: Amateurs Catch Predicted Nova Blowup p. 18

MAY 2010

Bring Back the

NIGHT Can we reverse light pollution? p.28

Hunting the Galaxy’s Heaviest Stars p. 22

Visit SkyandTelescope.com

Springtime Is Galaxy Time Dig Out Details in Your Images p. 72

p. 65

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Beautifully photographed in 4K digital cinematography, this film is a visually stunning chronicle of the history of the telescope from the time of Galileo, its profound impact upon the science of astronomy, and how both shape the way we view ourselves in the midst of an infinite universe.

Watch

April 9, 2010 Check your local listings

WATCH FOR OUR COMPANION PLANETARIUM SHOW Playing at a theater near you

BOOK & DVD Available from shopPBS.org, iTunes Store, Amazon and Barnes & Noble

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DVD/Download DVD/Do DDVD /Downl wnloadd

Underwriting support generously provided by 400 Years of the Telescope Production Partners

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May 2010 V O L . 119, N O . 5

FE ATURE S

18 Amateurs Catch

THI S M O N TH ’ S S K Y

40 43 45

Astronomers are conducting a frenetic search for our galaxy’s most massive star. By Yaël Nazé

46 48

Spectrum By Robert Naeye

8

May’s Sky at a Glance

10

Binocular Highlight

Letters 50 & 25 Years Ago By Leif J. Robinson

Planetary Almanac

12

News Notes

Sun, Moon, and Planets

58

New Product Showcase

70

Telescope Workshop

By Fred Schaaf

51

Exploring the Moon

By Gary Seronik

By Charles A. Wood

61

76

Gallery

86

Focal Point

Celestial Calendar By Alan MacRobert

By Constance E. Walker

65

Deep-Sky Wonders By Sue French

68

22

Going Deep By Ken Hewitt-White S &T TE S T R E P O R T

55

28 Saving the Night Sky COVER STORY

6

By Gary Seronik

Two dedicated backyard astronomers alerted professional telescopes worldwide and in space to U Scorpii’s eruption. By Mike Simonsen & Alan MacRobert

Most Massive Star

Northern Hemisphere’s Sky By Fred Schaaf

a Crucial Nova

22 The Quest for the

AL S O IN THI S I S S U E

Lunar Discoverer Mac and PC users alike can use this program to aid their telescopic explorations of the Moon.

Li Light pollution is worse than ever, but a new mindset and new bu technology are poised to slow te — and perhaps reverse — this bane of astronomy. By J. Kelly Beatty

18

34 Big Binos Versus These instruments have different but overlapping capabilities. By Tony Flanders

72 Digging Out the Details Layered deconvolution adds depth to your astro-images. By Ken Crawford

BARBARA HARRIS

Small Scopes

SKY & TELESCOPE (ISSN 0037-6604) is published monthly by Sky & Telescope Media, LLC, 90 Sherman St., Cambridge, MA 02140-3264, USA. Phone: 800-253-0245 (customer service/subscriptions), 888-253-0230 (product orders), 617-864-7360 (all other calls). Fax: 617-864-6117. Website: SkyandTelescope.com. © 2010 Sky & Telescope Media, LLC. All rights reserved. Periodicals postage paid at Boston, Massachusetts, and at additional mailing offices. Canada Post Publications Mail sales agreement #40029823. Canadian return address: 2744 Edna St., Windsor, ON, Canada N8Y 1V2. Canadian GST Reg. #R128921855. POSTMASTER: Send address changes to Sky & Telescope, PO Box 171, Winterset, IA 50273. Printed in the USA.

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A LEADER IN DESIGN AND MANUFACTURE OF ED-APO SYSTEMS “...even when its images were slightly out of focus they remained free of obvious color fringing...stars that danced around in turbulent seeing remained pure in color...”

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Robert Naeye Spectrum Founded in 1941 by Charles A. Federer, Jr. and Helen Spence Federer

The Fight Against Light Pollution: A Call to Arms

The Essential Magazine of Astronomy EDITORIAL

Editor in Chief Robert Naeye Senior Editors Dennis di Cicco, Alan M. MacRobert Associate Editor Tony Flanders Imaging Editor Sean Walker Editorial Assistant Katherine L. Curtis Editors Emeritus Richard T. Fienberg, Leif J. Robinson Senior Contributing Editors J. Kelly Beatty, Roger W. Sinnott

S&T: GREGG DINDERMAN

As i wrote a few months ago, amateur astronomy has entered a Golden Age. Manufacturers keep churning out better equipment and at more affordable prices. The internet, CCD cameras, and various electronic gizmos are making it easier than ever for amateurs to shoot astrophotos, conduct scientific research, share their successes with others, and enjoy the hobby. But the specter of light pollution looms over astronomy like a sword of Damocles. The problem continues to worsen, and in future decades the glare of artificial lighting might wipe out visual deep-sky observing for large stretches of the world’s landmasses. In the U.S., for example, light beamed into the sky is increasing 6% annually, four times the rate of population growth. Kelly Beatty (page 28) and Connie Walker (page 86) describe how people are waging a valiant battle against light pollution, often in conjunction with organizations such as the International Dark-Sky Association (IDA). Despite a growing awareness, an improving understanding of the problem, and new technologies, it’s not a battle we’re guaranteed to win. But it’s a battle that we must win if we want to preserve the grandeur of the heavens for later generations. The future of amateur astronomy is at stake. Light pollution takes away the same night sky we share with one another around the world, and that connects us to our ancestors. Heavily light-polluted skies fail to spark a sense of awe and wonder, making it less likely that people (especially children) will develop an interest in astronomy. There’s a lot that concerned astronomers can do about light pollution. First, remember that the problem is not light in general, it’s unnecessary light. Educate yourself about the issues and become knowledgeable about light fi xtures. Tell friends and neighbors that their night sky is disappearing, and that local governments are wasting huge sums of taxpayer money lighting up the sky. Tell them about how excessive glare can contribute to auto accidents and harm nocturnal wildlife. Join or support the IDA (www.darksky.org). Contact your local, state, or provincial government officials. We can’t afford to sit around and wish the problem away. Only sustained, concerted action will save our precious night sky.

Contributing Editors Greg Bryant, Paul Deans, Thomas A. Dobbins, David W. Dunham, Alan Dyer, Sue French, Paul J. Heafner, Ken Hewitt-White, Johnny Horne, E. C. Krupp, Emily Lakdawalla, David H. Levy, Jonathan McDowell, Fred Schaaf, Govert Schilling, Ivan Semeniuk, Gary Seronik, William Sheehan, Mike Simmons, Charles A. Wood, Robert Zimmerman Contributing Photographers P. K. Chen, Akira Fujii, Robert Gendler, Tony & Daphne Hallas ART & DESIGN

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Editor in Chief

6 May 2010 sky & telescope

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