Sky & Telescope - August 2020 - 45

Under the Stars by Fred Schaaf

Night of the
Perseids
Meteors are just one of the
attractions when this famous
summer shower peaks.

A K IR A FUJII

hat do the following have in common: ﬁlmmaker Steven Spielberg's childhood inspiration beneath
the night sky of southern New Jersey;
the single most dangerous object known
to humankind; and the burning tears of
an executed saint?
If you guessed that all three are
connected with August's famed Perseid
meteor shower, you're right! Spielberg's
ﬁrst summer under a really starry sky
inspired him to later include meteors
in many of his movies (most notably,
two meteors in Jaws). As for the "most
dangerous object," consider that Comet
Swift-Tuttle (the parent of the Perseids) has a larger nucleus than Halley's
Comet, and that it's on an orbit that
could eventually put it on a collision
course with Earth. That makes SwiftTuttle potentially the greatest threat to
our survival. Lastly, the Perseids long
ago became known as the ﬁery "tears
of Saint Laurence" because the shower's
peak originally coincided with the day
of his martyrdom, August 10, 258 AD.
But my topic this month isn't the
shower itself, rather, the starry sky you
can experience while watching Perseus
rise throughout the night.
Early evening. As detailed on page
48, this year's display peaks on the
night of August 11-12. The radiant is in
northern Perseus, just over the border
from Cassiopeia and not far from the
Double Cluster. As our Northern Hemisphere map on pages 42-43 illustrates,
this area is still very low in the northnortheast in the early evening, which
is why at mid-northern latitudes few
Perseids can be seen as the night begins.
In contrast, the wonders of the summer

p PERSEUS PLUS With the aid of our Northern Hemisphere Sky Chart on pages 42-43, see if you
can pick out Perseus, Cassiopeia, and Andromeda, as well as the Double Cluster and M31. The
radiant of the Perseid meteor shower lies near the Double Cluster.

Milky Way lie near (or on) the meridian. The nebulae M16, M17, M20, and
M8, open star cluster M11, and planetary nebula M57 are all well placed for
binocular and telescopic viewing. But
my advice is don't tire yourself out by
observing too much early on.
Late evening and the midnight
hour. Looking northeast you'll see the
zigzag pattern of Cassiopeia and the
stars of Perseus slowly climbing higher.
To the right of Perseus are the two
curved lines of Andromeda, the maiden
that Perseus heroically rescued. And
attached to Andromeda is the Great
Square of Pegasus, standing on its
southeast corner like a giant diamond.
Under good conditions, you should
catch quite a few swift Perseids shooting away from the northeast as midnight (daylight-saving time) arrives. The
slightly bad news for Perseid watchers
this year is that the nearly last-quarter
Moon rises not long after midnight as
the night of the 11th transitions into
the morning of the 12th. Fairly bright

moonlight will decrease the visibility
of meteors just as the shower's radiant gains altitude and the pace of the
display should be picking up.
1 a.m. to dawn. These are the hours
when Perseid meteors should be most
numerous. By 1 a.m., the bright light
of Capella has risen, while off to its
right is the lovely Pleiades star cluster,
not far from the Moon. In the next few
hours, Aldebaran and the Hyades also
appear. However, you'll have to wait
until a little after 3 a.m. for Orion to
fully clear the east horizon. For many of
us, Perseid night often provides our ﬁrst
view of Orion since mid-spring. It's also
the ﬁrst chance we'll have to check the
brightness of Betelgeuse.
Morning twilight begins to interfere
with Perseid observing soon after 4:30
a.m. I'm almost always too tired by then
to stay up any longer and watch the
heliacal rising of Sirius.
¢ FRED SCHAAF welcomes your letters
and comments at fschaaf@aol.com.
sk yandtelescope.org * AUGUST 2 02 0

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Sky & Telescope - August 2020

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