Skywatch - 2021 - 40

AUGUST | 2021

PLANETS IN
AUGUST

CASSIOPEIA
Andromeda
Galaxy

Perseid
radiant

Double
Cluster

ANDROMEDA
PERSEUS
TRIANGULUM
Capella

Looking Northeast at 11 p.m.

- that's what we're looking for. Point
your binoculars at Vega, and in the same
field of view you should spot Epsilon.
Now point a scope at Epsilon and bump
up the magnification - each component
should split into doubles themselves.
That's why it's called the Double Double!
Staying in the Summer Triangle, hop
across to Deneb in Cygnus, the Swan.
The star's name derives from the Arabic
al dhanab for "tail." Do you remember
where we last encountered this? Yes, in
March when we discussed Denebola,
Leo's tail star. Originally, Deneb

referred to the tail of a hen! From Deneb
slide along the body of the Swan to find
Albireo marking its head, about halfway
between Vega and the third Summer
Triangle star, Altair. Albireo is one of the
prettiest double stars in the sky. A small
scope will easily split it into two gems,
one blue and one gold. But remember
color perception is subjective, so these
colors might look a bit diﬀerent to you.
And, of course, don't forget that all of
July's nebulae are still beautifully placed
over the southern horizon. You'll have
plenty do while waiting for the Perseids.

AKIRA FUJII

T Left:

The two components of the wide double star Epsilon Lyrae are just discernible in this image. If we
could "zoom in" on this pair, as we do when we look at a magniﬁed view through a telescope's eyepiece,
we could see that each of these stars is also a binary system. Right: August is all about the gas giants.
Jupiter and Saturn both reach opposition this month, which means you can observe them all night long,
starting shortly after sunset. A splendid waxing gibbous Moon joins the planets on August 20-21 - be
sure to look toward the southeast those evenings to catch this sight.

Dusk, Aug 20 -21
45 minutes after sunset

10°

Mercury is in conjunction with the Sun on
August 1st and out of naked-eye view for
the entire month. However, if you use binoculars you might glimpse the planet very low
in the west at dusk at the end of the month.
Venus is very slowly climbing up
from the western horizon at dusk, where
it reigns as the Evening Star - evening
twilight is beginning to shorten, and the
sky grows darker earlier. At dusk on the
10th, Venus is joined by a thin, waxing
crescent Moon, roughly 5½° to its right.
Mars is strictly a target for binoculars and telescopes this month. Your best
chance to spot it comes on the 9th when a
razor-thin crescent Moon is positioned about
3½° above and to its right. Don't be disappointed if you don't spot the Red Planet,
however, since both objects will be very low
in the west and awash in bright twilight.
August is a big month for both
Jupiter and Saturn: They reach opposition and are observable all night long and
positioned near the meridian in the middle
of the night. Saturn reaches this milestone
on the 2nd, followed by Jupiter on the 19th.
No one has to be told to check out Saturn's
rings, which this year remain favorably
tilted earthward, but don't forget its big
moon, 8.5-magnitude Titan. Jupiter's cloud
belts, festoons, and spots are endlessly
fascinating. Its Great Red Spot has been
shrinking in recent decades, but is still quite
an easy sight in a 4-inch scope. And of
course, Jupiter's four bright Galilean moons
provide nightly entertainment as they swing
around the planet. You can even spot two or
three of these mini-worlds in binoculars.

CAPRICORNUS
Saturn

LY R A
β

Jupiter

Moon
Aug 20

Moon
Aug 21

Looking Southeast

40 SK Y WATCH 2021

Historical Events
8/1: Caroline
Herschel
discovers her fi rst
comet, Comet
Herschel (C/1786
P1), 1786

8/1: Nicolas Sarabat
discovers Comet
Sarabat (C/1729 P1),
the brightest and
possibly largest comet
ever seen, 1729

Skywatch - 2021

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