Sky & Telescope - March 2024 - 50

MARCH 2024 OBSERVING
Celestial Calendar
Action at Jupiter
Antares Blinks Again
MOST OBSERVERS will have at least
one opportunity to see the Moon occult
Antares in the next few years. Perhaps
it's your turn this month. On the
morning of March 3rd, the last-quarter
Moon eclipses Scorpius's brightest star
for viewers in the southeastern U.S.
and Mexico, Central America, and the
northern third of South America. Those
outside of the occultation zone will see
a very close conjunction.
From the southeastern U.S., observers
will witness both the star's disappearance
and reappearance, but even as far
west as Des Moines, Iowa, Antares will
pop out from behind the Moon's dark
limb just after local moonrise. Be sure
to find a location with an unobstructed
view to the southeast, as the pair will
hover quite low especially at the start of
the occultation, around 2 a.m. EST.
Antares is a double star, so if you're
Minima of Algol
Feb.
UT
1
4
7
10
13
16
19
21
24
27
20:25
17:14
14:04
10:53
7:43
4:32
1:21
22:11
19:00
15:49
Mar.
1
4
7
10
12
15
18
21
24
27
30
located where the reappearance phase of
the occultation is visible, you can try to
glimpse the 5.4-magnitude companion
star, Antares B. Just before 1st-magnitude
Antares A and its glare reemerge,
carefully watch the Moon's dark limb
for the B star. Antares B is just 2.7″ west
of the primary, so it'll precede its brilliant
companion by just a few seconds.
A second occultation occurs on the
evening of March 18th. That's when the
dark limb of the waxing gibbous Moon
occults the 4th-magnitude red giant
Upsilon (υ) Geminorum, which is situated
2.4° southwest of Pollux. If you live
in the southeastern, central, or western
U.S., Central America, or western South
America, you've got a ticket for the show.
For more details about either
occultation, visit the International
Occultation Timing website at:
lunar-occultations.com/iota/.
FOR TELESCOPE USERS, March
represents the grand finale of Jupiter's
current apparition. On the 1st of the
month the planet hovers 49° above the
western horizon some 30 minutes after
sunset, but by the 31st that figure has
decreased to just 27°. Generally, when
an object has an altitude of less than
roughly 30° the steady seeing conditions
that high-magnification viewing
requires becomes exceedingly rare.
Jupiter has its conjunction with the
Sun on May 18th, after which it will
reemerge at dawn. In other words, get
your last looks in now - you won't get
as good an opportunity to inspect the
planet again until sometime in mid-July.
Any telescope reveals the four big
Galilean moons, and binoculars usually
show at least two or three. The moons
orbit Jupiter at different rates, changing
positions along an almost straight line
from our point of view on Earth. Use the
diagram on the facing page to identify
them by their relative positions on any
given date and time. All the observable
interactions between Jupiter and its satellites
and their shadows are tabulated
on the facing page. Find events timed
for when Jupiter is at its highest.
Features on Jupiter appear closer to
UT
29
12:39
9:28
6:17
3:07
23:56
20:45
17:35
14:24
11:13
8:03
4:52
These geocentric predictions are from the recent
heliocentric elements Min. = JD 2457360.307 +
2.867351E, where E is any integer. They were
derived by Roger W. Sinnott from 15 photoelectric
series in the AAVSO database acquired during
2015-2020 by Wolfgang Vollmann, Gerard Samolyk,
and Ivan Sergey. For a comparison-star chart
and more info, see skyandtelescope.org/algol.
50 MARCH 2024 * SKY & TELESCOPE
18
30
PERSEUS
38
Algol
21
the central meridian than to the limb
for 50 minutes before and after transiting.
Here are the times, in Universal
Time, when the Great Red Spot should
cross Jupiter's central meridian. The
dates, also in UT, are in bold. (Eastern
Daylight Time is UT minus 4 hours.)
February 1: 8:52, 18:48; 2: 4:44,
TRIANGULUM
34
Perseus is conveniently high in the northwest
during evening hours in March. Every
2.87 days, Algol (Beta Persei) dips from its
usual magnitude 2.1 to 3.4 and back. Use this
chart to estimate its brightness in respect to
comparison stars of magnitude 2.1 (Gamma
Andromedae) and 3.4 (Alpha Trianguli).
14:40; 3: 0:36, 10:31, 20:27; 4: 6:23,
16:19; 5: 2:15, 12:10, 22:06; 6: 8:02,
17:58; 7: 3:54, 13:49, 23:45; 8: 9:41,
19:37; 9: 5:33, 15:29; 10: 1:24, 11:20,
21:16; 11: 7:12, 17:08; 12: 3:03, 12:59,
22:55; 13: 8:51, 18:47; 14: 4:43, 14:38;
15: 0:34, 10:30, 20:26; 16: 6:22, 16:18;
17: 2:13, 12:09, 22:05; 18: 8:01, 17:57;
19: 3:53, 13:48, 23:44; 20: 9:40, 19:36;
21: 5:32, 15:28; 22: 1:23, 11:19, 21:15;
23: 7:11, 17:07; 24: 3:03, 12:58, 22:54;
25: 8:50, 18:46; 26: 4:42, 14:38; 27:
0:33, 10:29, 20:25; 28: 6:21, 16:17;
29: 2:13, 12:08, 22:04
http://www.lunar-occultations.com/iota/ http://www.skyandtelescope.org/algol
Sky & Telescope - March 2024

Table of Contents for the Digital Edition of Sky & Telescope - March 2024
