Sky & Telescope - April 2021 - 2
CONTENTS
THE ESSENTIAL GUIDE TO ASTRONOMY
April 2021
VOL. 141, NO. 4
FEATURES
Cover Story:
12 How Well Do We Know
the Sun?
Even though the Sun is our nearest
star, we may not understand it as
well as we thought.
By Colin Stuart
A compact collection of galaxies
warrants not only observing but
also sketching.
By Howard James Banich
24 Resurrecting a Classic
Refractor
It took an astronomer who refused
to give up on herself to save a
historic observatory for a new
generation.
By M. Nicole Nazzaro
34 The Mystery of the
Martian Moons
Planetary scientists may soon
discover how the Red Planet
acquired its two potato-shaped
companions.
By Javier Barbuzano
62 Choosing an Astrograph
Here's a clever way to compare
features in deep-sky imaging scopes
before making a purchase.
By Oleg Bouevitch
ON THE COVER
62
OBSERVING
41
April's Sky at a Glance
By Diana Hannikainen
42
Lunar Almanac & Sky Chart
43
Binocular Highlight
By Mathew Wedel
PHOTO: N ASA / SDO
2
30
Orion's StarShoot G16
Deep Space Camera
By Johnny Horne
4
Spectrum
By Peter Tyson
44
Planetary Almanac
6
From Our Readers
45
Evenings with the Stars
By Fred Schaaf
7 75, 50 & 25 Years Ago
By Roger W. Sinnott
46
Sun, Moon & Planets
By Gary Seronik
8
48
Celestial Calendar
By Bob King
52
Exploring the Solar System
By Charles Wood
COLUMNS / DEPARTMENTS
54
58
First Exposure
By Ron Brecher
Going Deep
By Al Lamperti & Frank Colosimo
News Notes
57
Book Review
By M. Nicole Nazzaro
68
New Product Showcase
70 Astronomer's Workbench
By Jerry Oltion
72
Gallery
84
Focal Point
By Martin Hajovsky
ONLINE
SKY AT A GLANCE
Our popular column highlights celestial delights for the upcoming week,
complete with simple star maps and
observing tips.
skyandtelescope.org/ataglance
Extreme UV image
of the Sun, taken on
October 8, 2014
S&T TEST REPORT
ASTROPHOTO GALLERY
Enjoy readers' best images and
upload your own to share with your
fellow enthusiasts. Be sure to check
out the Editor's Choice winners.
skyandtelescope.org/gallery
ONLINE STORE
Equip yourself for astronomy excellence with webinars, sky atlases,
and more staff-selected products.
shopatsky.com
SKY & TELESCOPE (ISSN 0037-6604) is published monthly by AAS Sky Publishing, LLC, owned by the American Astronomical Society, 1667 K Street NW, Suite 800, Washington, DC
20006, USA. Phone: 800-253-0245 (customer service/subscriptions), 617-500-6793 (all other calls). Website: skyandtelescope.org. Store website: shopatsky.com. ©2021 AAS Sky
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Sky & Telescope - April 2021
Table of Contents for the Digital Edition of Sky & Telescope - April 2021
Contents
Sky & Telescope - April 2021 - Cover1
Sky & Telescope - April 2021 - Cover2
Sky & Telescope - April 2021 - 1
Sky & Telescope - April 2021 - Contents
Sky & Telescope - April 2021 - 3
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