CONTENTS August 2019 - Sky & Telescope
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SKY & TELESCOPE BEGINNERS’ GUIDE Print out our free, 10-page handout to give out at star parties and other community events. skyandtelescope.com/ getting-started EXPLORE THE NIGHT BLOG Follow Contributing Editor Bob King each week as he takes readers on an adventure through the sky. skyandtelescope.com/king BUILD COMMUNITY Seeking fellow enthusiasts? Find clubs and other organizations in your area, or add yours to our listings. skyandtelescope.com/ astronomy-clubs-organizations ESO Find us on Facebook & Twitter SKY & TELESCOPE (ISSN 0037-6604) is published monthly by Sky & Telescope, a division of F+W Media, Inc., 90 Sherman St., Cambridge, MA 02140-3264, USA. Phone: 800-253- 0245 (customer service/subscriptions), 617-864-7360 (all other calls). Fax: 617-864-6117. Website: skyandtelescope.com. Store website: shopatsky.com. ©2019 F+W Media, Inc. 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 420235, Palm Coast, FL 32142-0235. Printed in the USA. ONLINE X-rays reveal swirling hot gas in the Perseus galaxy cluster. ON THE COVER PHOTO: NASA / CXC / GSFC / S. A. WALKER ET AL. FEATURES Cover Story: 14 Pioneers of the Invisible Universe Researchers seeking the X-ray sky revealed a hot, lively, and revolu- tionary cosmos. By Monica Young 22 Small-Scope Summer Embrace the constraints of a small instrument for deep-sky observing this season. By Brian Ventrudo 28 Catch a Wind-Blown Bubble Mysterious in origin and ethereal in nature, Wolf-Rayet nebulae intrigue both observer and reader alike. By Steve Gottlieb 34 Red Dwarf Habitability Recipe Life on worlds around the smallest stars would cope with environments vastly different from our own. By Igor Palubski & Aomawa Shields 58 Governing the Planets This year marks the 400th anniver- sary of Kepler’s Third Law of Planetary Motion. By F. Michael Witkoski 64 Smartphone Nightscaping The ever-improving quality of cameras in smart devices makes nightscape astrophotography a snap. By Jeff Dai S&T TEST REPORT 68 Nikon’s Mirrorless Z6 By Alan Dyer COLUMNS / DEPARTMENTS 4 Spectrum By Peter Tyson 6 From Our Readers 7 75, 50 & 25 Years Ago By Roger W. Sinnott 8 News Notes 74 Astronomer’s Workbench By Jerry Oltion 76 Gallery 83 Event Calendar 84 Focal Point By Dennis Kelly OBSERVING 41 August’s Sky at a Glance 42 Lunar Almanac & Sky Chart 43 Binocular Highlight By Mathew Wedel 44 Planetary Almanac 45 Under the Stars By Fred Schaaf 46 Sun, Moon & Planets By Fred Schaaf 48 Celestial Calendar By S. N. Johnson-Roehr 52 Exploring the Moon By Charles A. Wood 54 Deep-Sky Wonders By Sue French THE ESSENTIAL GUIDE TO ASTRONOMY CONTENTS 2 AUGUST 2019 • SKY & TELESCOPE August 2019 VOL. 138, NO. 2 28
Transcript of CONTENTS August 2019 - Sky & Telescope
2 M A RC H 2 018 • SK Y & TELESCOPE
BEGINNERS’ GUIDEPrint out our free, 10-page handout to give out at star parties and other community events. skyandtelescope.com/ getting-started
EXPLORE THE NIGHT BLOGFollow Contributing Editor Bob King each week as he takes readers on an adventure through the sky.skyandtelescope.com/king
BUILD COMMUNITYSeeking fellow enthusiasts? Find clubs and other organizations in your area, or add yours to our listings.skyandtelescope.com/ astronomy-clubs-organizations
ES
O
Find us on Facebook & Twitter
SKY & TELESCOPE (ISSN 0037-6604) is published monthly by Sky & Telescope, a division of F+W Media, Inc., 90 Sherman St., Cambridge, MA 02140-3264, USA. Phone: 800-253-0245 (customer service/subscriptions), 617-864-7360 (all other calls). Fax: 617-864-6117. Website: skyandtelescope.com. Store website: shopatsky.com. ©2019 F+W Media, Inc. 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 420235, Palm Coast, FL 32142-0235. Printed in the USA.
ONLINE
X-rays reveal swirling hot gas in the Perseus galaxy cluster.
ON THE COVER
PHOTO: NASA / CXC / GSFC / S. A. WALKER ET AL.
FEATURES
Cover Story:14 Pioneers of the Invisible Universe Researchers seeking the X-ray sky revealed a hot, lively, and revolu- tionary cosmos. By Monica Young
22 Small-Scope Summer Embrace the constraints of a small instrument for deep-sky observing this season. By Brian Ventrudo
28 Catch a Wind-Blown Bubble Mysterious in origin and ethereal in nature, Wolf-Rayet nebulae intrigue both observer and reader alike. By Steve Gottlieb
34 Red Dwarf Habitability Recipe Life on worlds around the smallest stars would cope with environments vastly different from our own. By Igor Palubski & Aomawa Shields
58 Governing the Planets This year marks the 400th anniver- sary of Kepler’s Third Law of Planetary Motion. By F. Michael Witkoski
64 Smartphone Nightscaping The ever-improving quality of cameras in smart devices makes nightscape astrophotography a snap.
By Jeff Dai
S&T TEST REPORT
68 Nikon’s Mirrorless Z6 By Alan Dyer
COLUMNS / DEPARTMENTS
4 Spectrum By Peter Tyson 6 From Our Readers 7 75, 50 & 25 Years Ago By Roger W. Sinnott 8 News Notes 74 Astronomer’s Workbench By Jerry Oltion 76 Gallery 83 Event Calendar 84 Focal Point By Dennis Kelly
OBSERVING
41 August’s Sky at a Glance 42 Lunar Almanac & Sky Chart 43 Binocular Highlight By Mathew Wedel 44 Planetary Almanac 45 Under the Stars By Fred Schaaf 46 Sun, Moon & Planets By Fred Schaaf 48 Celestial Calendar By S. N. Johnson-Roehr 52 Exploring the Moon By Charles A. Wood 54 Deep-Sky Wonders By Sue French
T H E E S S E N T I A L G U I D E TO A S T R O N O M Y
CONTENTS
2 AU G U S T 2 019 • SK Y & TELESCOPE
August 2019 VOL. 138, NO. 2
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