Sky & Telescope - November 2024 - 48

BOB KING
NOVEMBER 2024 OBSERVING
Celestial Calendar by Bob King
A Trio of Lunar Occultations
This month the Moon passes in front of Neptune, the Pleiades, and Spica.
be seen. While binoculars may reveal
the main stars, a telescope will provide
the best view of the event.
From many locations across North
Spica shines just to the east (left) of the first-quarter Moon shortly before being occulted
on July 13, 2024. From Duluth, Minnesota, the event occurred during twilight, but the star
was easily visible in binoculars before sunset. The crescent Moon will hide Spica again
on November 27th during the early morning hours.
Y
ou probably don't read this magazine
for the latest astrology news.
Still, you might be interested to know
that aficionados of the subject and
other related spiritual beliefs celebrate
Occult Day in November. Amateur
astronomers can " join in " by watching
the Moon occult Neptune on November
11th, the Pleiades on November 15-16,
and Spica on November 27th.
The fun begins the evening of the
11th when the dark limb of the 10-dayold
gibbous Moon eclipses 7.8-magnitude
Neptune for most of the U.S.
(except the northwest), eastern Canada,
Central America, and Greenland. From
many locations it will take the Moon
about 6 to 8 seconds to cover the distant
planet's tiny, 2.3″-diameter disk.
Observers in the eastern third of North
America, Central America, and northern
South America also get an appetizer:
Roughly 90 minutes before the
Neptune occultation, the Moon eclipses
5.5-magnitude 20 Piscium.
48 NOVEMBER 2024 * SKY & TELESCOPE
Despite the brilliance of the
80%-illuminated Moon, a small scope
should suffice to extract Neptune from
the lunar glare - at least at disappearance.
The ice giant's reappearance on
the bright limb will be considerably
more challenging! Use magnification
upwards of 200× to contrast Neptune's
bluish disk next to the bone-white
lunar landscape. For an extensive list
of cities and times for the planet's
disappearance and reappearance, visit
the International Occultation Timing
Association's dedicated web page
https://is.gd/IOTA_Neptune.
When the full Beaver Moon gleams
over frosty forests on November 15-16,
it'll be concealing a secret. Nearly
hidden within its light is one of the
sky's most beloved star clusters, the
Pleiades. But instead of glittering - in
the words of Alfred, Lord Tennyson -
" like a swarm of fireflies tangled in a
silver braid, " the dipper-shaped group is
awash in moonlight and struggling to
and Central America, the Moon will
occult several of the cluster's brightest
stars, including Merope, Alcyone, Electra,
and Atlas. Observers in the eastern
half of the U.S. witness this multi-star
occultation in the early morning hours,
while in the Pacific Time Zone it begins
around 10 p.m. local time on the 15th
and concludes after 1 a.m. on the 16th.
Due to the Moon's proximity to
Earth, it exhibits significant parallax,
which causes its path across the cluster
to vary depending on your location.
To find out which stars you can see
occulted, simulate the event using a
stargazing app such as Stellarium to step
through the event with the software set
to your specific location.
For me, the peak occultation
experience is witnessing a bright star
or planet disappearing or reappearing
along the smoky, earthlit side of a
crescent Moon. Lunar glare is minimal
and the ability to clearly see the
approaching (or departing) limb adds
a three-dimensional quality to the
scene. Observers across more than half
of both the U.S. and Canada will have
this sight delivered on a silver platter
on the morning of the 27th when the
13%-illuminated waning lunar crescent
blots out 1st-magnitude Spica. Both the
bright-limb disappearance and dramatic
reappearance at the dark limb are
visible from the Midwest and the Eastern
U.S., but even observers as far west
as Denver, Colorado, can watch the star
reemerge shortly after moonrise.
For full details, go to IOTA's website,
https://is.gd/Spica_Nov27.

https://www.is.gd/IOTA_Neptune https://www.is.gd/Spica_Nov27

Sky & Telescope - November 2024

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