44 FEBRUARY 2020 • SKY & TELESCOPE
Mercury
Saturn
Uranus
Neptune
10 "
Feb 1 10 20 29
1215 9
11529
15
15
Venus
Jupiter
Mars
FEBRUARY 2020 OBSERVING
Planetary Almanac
The Sun and planets are positioned for mid-February; 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). “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.
The table above gives each object’s right ascension and declination (equinox 2000.0) at 0h Universal Time on selected dates,
and its elongation from the Sun in the morning (Mo) or evening (Ev) sky. Next are the visual magnitude and equatorial diameter.
(Saturn’s ring extent is 2.27 times its equatorial diameter.) Last are the percentage of a planet’s disk illuminated by the Sun and
the distance from Earth in astronomical units. (Based on the mean Earth–Sun distance, 1 a.u. is 149,597,871 kilometers, or
92,955,807 international miles.) For other dates, see skyandtelescope.com/almanac.
PLANET VISIBILITYMercury: low in the west-southwest at dusk through the 17th •
Venus: high at dusk, sets mid-evening •Mars: rises around 4 a.m., reasonably high in the south-
southeast b y dawn •Jupiter: low at dawn •Saturn: very low at dawn starting on the 7th
PLANET DISKShave south up, to match the
view in many telescopes. Blue ticks indicate the
pole currently tilted toward Earth.
PEGASUS
Rigel
Betelgeuse
CANIS
MAJOR
PISCES
Sirius
ORION
Pleiades
CANCER TAURUS
Pollux
Castor
Procyon
Arcturus
CORVUS
GEMINI
VIRGO
BOÖTES
LIBRA
Spica
LEO
HYDRA
Vega
HERCULES
CYGNUS
SCORPIUS
OPHIUCHUS
Antares
SAGITTARIUS
AQUILA
ERIDANUS CETUS
ARIES
Regulus
ECL
IPTI
C
LOCAL TIME OF TRANSIT
RIGHT ASCENSION
DECLINATION
+30°
+40°
–10°
–30°
–40°
0°
+20°
+10°
10 am 8 am 6 am 4 am 2 am Midnight 10 pm 8 pm 6 pm 4 pm 2 pm
+20°
+10°
+30°
+40°
0°
–20°
–30°
–40°
18 h 16 h 14 h 12 h 10 h 8 h 6 h 4 h 2 h 0 h 22 h
EQUATOR
Jupiter
Saturn
Uranus
Neptune
Mercury
Venus
Mars
13
Feb 8– 9
19
16
Feb 1
28
4
44 FEBRUARY 2020 • SKY & TELESCOPE
Date Right Ascension Declination Elongation Magnitude Diameter Illumination Distance
Sun^120 h 55.0m –17° 23′ —–26.83^2 ′^28 ′′ —0.985
29 22 h 44.6m –7° 58′ —–26.83 2 ′ 18 ′′ — 0.991
Mercury^121 h 53.6m –14° 05′ 14° Ev –1.0 5.6′′ 85% 1.192
10 22 h 40.0m –7° 48′ 18° Ev – 0.7 7.0′′ 55% 0.965
20 22 h 48.4m –4° 14′ 12° Ev +2.1 9.4′′ 11% 0.712
29 22 h 16.6m –6° 55′ 7° Mo +4.2 10.7′′ 3% 0.630
Venus 123 h 30.7m –4° 07′ 40° Ev –4.1 15.3′′ 73% 1.090
10 0 h 08.9m +0° 35′ 42° Ev –4.2 16.2′′ 70% 1.030
20 0 h 50.5m +5° 47′ 43° Ev –4.2 17.4′′ 67% 0.960
29 1 h 27.5m +10 ° 17′ 44° Ev –4.3 18.6′′ 63% 0.896
Mars 117 h 12.7m –22° 59′ 52° Mo +1.4 4.8′′ 93% 1.948
15 17 h 54.4m –23° 37′ 57° Mo +1.3 5.1′′ 92% 1.835
29 18 h 36.5m –23° 34′ 61° Mo +1.1 5.4′′ 91% 1.721
Jupiter^118 h 58.2m –22° 43′ 28° Mo –1.9 32.5′′ 100% 6.067
29 19 h 22.7m –22° 05′ 51° Mo –2.0 34.1′′ 99% 5.780
Saturn 119 h 46.8m –21° 09′ 17° Mo +0.6 15.1′′ 100% 10.972
29 19 h 59.5m –20° 37′ 42° Mo +0.7 15.5′′ 100% 10.745
Uranus^152 h 03.4m +12 ° 0 2′ 67° Ev +5.8 3.5′′ 100% 20.171
Neptune 15 23 h 14.8m –5° 57′ 22° Ev +8.0 2.2′′ 100% 30.847
February Sun & Planets