Sky & Telescope - April 2023 - 47

+30°
+40°
+20°
Jupiter
0°
Neptune
-20°
-10°
-30°
-40°
Saturn
Apr 16
CETUS
Fomalhaut
10 am
CAPRICORNUS
8 am
13
SAGITTARIUS
6 am
10
SCORPIUS
4 am
2 am
Midnight
LOCAL TIME OF TRANSIT
10 pm
8 pm
6 pm
4 pm
2 pm
LIBRA
CORVUS
HYDRA
CANIS
MAJOR
-30°
-40°
The Sun and planets are positioned for mid-April; the colored arrows show the motion of each during the month. The Moon is plotted for evening
dates in the Americas when it's waxing (right side illuminated) or full, and for morning dates when it's waning (left side illuminated). " Local time of transit "
tells when (in Local Mean Time) objects cross the meridian - that is, when they appear due south and at their highest - at mid-month. Transits
occur an hour later on the 1st and an hour earlier at month's end.
that Mars actually eclipsed Epsilon on
April 7, 1976 - a much-anticipated
and very rare event that attracted the
interest of amateur astronomers and
research groups around the world. And
this evening the planet and star are as
close as they've been since that fateful
meeting 47 Aprils ago.
This time, Mars will approach to
within 9′ of the star at 2:09 p.m. EDT.
By the time twilight starts to fade in
North America, the planet's eastward
motion will have carried it a little
farther from the star - something more
Moon
Apr 23
Dusk, April 20 - 23
30 minutes after sunset
like 13′. You should have no problem
seeing both objects without optical aid,
but binoculars will greatly enhance the
view. Mars is quite close to the star on
the preceding and following evenings,
but this really is the best night. And you
don't want to miss out - Mars won't be
this close to Epsilon again until 2055.
SUNDAY, APRIL 23
Whenever Venus serves as the Evening
Star, you're guaranteed at least one
striking conjunction with the Moon
each month. Sometimes two. Just as
twilight begins to fade tonight, cast
your gaze toward the west-northwest
to see a pretty, earthlit lunar crescent
standing some 5° upper left of brilliant
Venus
Aldebaran
Moon
Apr 22
Moon
Apr 26
Pleiades
TAURUS
Moon
Apr 21
Moon
Apr 25
Mars
Mercury
Moon
Apr 20
Looking West-Northwest
Moon
Apr 24
GEMINI
Pollux
Castor
Moon
Apr 27
April 24 - 27
9 pm
Venus. That's splendid. But what makes
this evening's sight extra special are the
supporting players, which include Mars
and the bright stars of winter marching
toward the horizon. Although we've
opted to highlight this date, in fact
the lunar crescent is nearly as close to
Venus on the preceding evening, so you
really have two opportunities to catch
these luminaries together. Indeed, if you
are on the West Coast, the gap between
the Moon and Venus is actually smaller
on the evening of the 22nd.
TUESDAY, APRIL 25
Before the month wraps up, Mars and
the Moon have one last duty to perform.
Tonight, they meet in Gemini,
some 8° below the constellation's two
brightest stars, Castor and Pollux. The
waxing lunar crescent sits less than
3° right of Mars in what is the closest
Moon-planet pairing this month.
In some respects, this event echoes
last December's very close conjunction
(or, occultation, depending on your
location) but is much less spectacular.
Back then, the Red Planet was at opposition
and gleamed brilliantly at magnitude
-1.8 while the Moon was full.
Still, taken for what it is, tonight's sight
is nevertheless very attractive, set as it
is within the luminous Winter Hexagon
and with Venus nearby for extra luster.
Looking West, high in the sky
¢ Consulting Editor GARY SERONIK has
been keeping an eye on the sky long
enough to recall the previous time Mars
and Epsilon Geminorum met.
sk yand tele scope .o r g * APRIL 2023
47
ERIDANUS
0h
22h
20h
CYGNUS
PEGASUS
PISCES
AQUARIUS
AQUILA
HERCULES
OPHIUCHUS
April
5 -6
18h
Vega
16h
14h
BOÖTES
Arcturus
VIRGO
LEO
1
ORION
Regulus
Procyon
CANCER
EQUATOR
Sirius
Rigel
Betelgeuse
Uranus
TAURUS
0°
-20°
-10°
12h
RIGHT ASCENSION
Castor
Pollux
27
Mars
10h
8h
GEMINI
6h
AURIGA
Apr
24
4h
Venus
Pleiades
ARIES
+30°
+40°
Mercury
+20°
DECLINATION
E
C
L
I
P
T
I
C

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Sky & Telescope - April 2023

Table of Contents for the Digital Edition of Sky & Telescope - April 2023