Sky & Telescope - August 2022 - 45

Evenings with the Stars by Fred Schaaf
Vacationing in the Milky Way
Get ready for a starry summer tour of our home galaxy.
I
t's time to make your reservations
for a vacation in the most grand and
luxurious of all astronomical resorts:
the summer Milky Way.
Some of us can still enjoy the full
glory of our home galaxy from our own
backyards - the ultimate " staycation. "
Sadly, however, due to light pollution
the vast majority of people living in the
United States and elsewhere have completely
lost sight of this starry wonder.
Most readers will have to travel many
miles to escape city lights in order to
fully enjoy the night sky.
In addition to choosing your viewing
spot, the timing of a Milky Way " vacay "
is also vital. Any bright moonlight can
hinder your view, washing out the softly
glowing band of light. You want to be
sure to book your reservation for both
the dark-of-the-Moon period and for
when the Milky Way arches highest
across the sky. This August, there are
two good openings - a brief one at the
start of the month, and a longer stretch
in the second half. During August, you
can view the Milky Way after moonset
until around the 7th, but toward the
end of that run you'll have to wait until
after midnight for the Moon to set. The
second, prime window opens on the
evening of the 15th and lasts until the
beginning of September, when the lunar
crescent returns to the evening sky.
Of course, as with any vacation,
we sometimes have to deal with poor
weather, including summer haze. That
haze is thickest near the horizon, where
it can interfere with our views of the
glorious Sagittarius and Scorpius Milky
Way, which rides low in the south for
observers at mid-northern latitudes.
Let's begin our travels near the
zenith, in Cygnus. The Swan - also
pictured as the Northern Cross - is
enwreathed with one of the Milky
Way's brightest sections, the Cygnus
STAR ATTRACTION The most exciting Milky Way destination for stargazers is the rich
swath found in the constellation Sagittarius, seen just above the treeline in this photo.
sk yand tele scope .o r g * AUGUST 2022 45
Star Cloud. This region is so bright that
I can glimpse it with the naked eye even
when the limiting stellar magnitude is
as bright as 4.8 - typical for fairly small
cities and many suburbs.
Under darker skies, we can begin
to perceive some of the major dark
indentations in the Milky Way caused
by clouds of interstellar dust. The most
famous of these is the Great Rift, which
starts in Cygnus and splits the Milky
Way, with the eastern arm of this luminous
river extending southward toward
the horizon and into Sagittarius, while
the western channel comes to an end in
northern Ophiuchus. About 7° northnortheast
of Deneb is a lesser-known
dark cloud, which nevertheless is pretty
easy to see in good conditions. It cuts
perpendicularly most of the way across
the band of the Milky Way.
Midway up in the south on August
evenings you'll find the roundish, bright
glow of the Scutum Star Cloud. The
great visual astronomer Edward Emerson
Barnard called it " the gem of the
Milky Way, " and few would disagree.
Smaller, irregularly shaped patches of
bright Milky Way stand out southwest
of the Scutum Star Cloud. The Gamma
Scuti Star Cloud is small but intense,
and so, too, is the glowing knot of
the Small Sagittarius Star Cloud, also
known as M24.
At last, we arrive at the Large Sagittarius
Star Cloud - the huge puff of
steam rising from the spout of the
Sagittarius Teapot. This wondrous
region roughly marks the location of the
physical center of the Milky Way Galaxy,
though the actual galactic center is
hidden by many thousands of lightyears
of interstellar dust. This swath
of northwest Sagittarius and southeast
Scorpius offers naked-eye wonders such
as M8, the Lagoon Nebula, and the big
open clusters M6 and M7, just above
the Stinger of Scorpius. It's a satisfying
place to wrap up our Milky Way holiday.
¢ FRED SCHAAF enjoyed his best summer
vacation 40 years ago when he saw
a total lunar eclipse, sky-filling northern
lights, and colorful volcanic twilights.
ALAN DYER
http://www.skyandtelescope.com
Sky & Telescope - August 2022

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