My first Magazine Sky & Telescope - 02.2019 | Page 46

FEBRUARY 2019 OBSERVING
Planetary Almanac
PLANET VISIBILITY Mercury: visible at dusk after the 12th • Venus: visible at dawn
all month • Mars: visible at dusk, sets before midnight • Jupiter: visible at dawn all month •
Saturn: visible at dawn all month
Mercury
Feb 1
10
28
19
February Sun & Planets
Venus
Date Right Ascension Declination Elongation Magnitude Diameter Illumination Distance
1 20 h 56.1 m –17° 19′ — –26.8 32′ 28″ — 0.985
28 22 h 41.8 m –8° 15′ — –26.8 32′ 18″ — 0.990
1 21 h 03.9 m –18° 56′ 2° Ev –1.5 4.8″ 100% 1.397
10 22 h 06.6 m –13° 22′ 8° Ev –1.3 5.1″ 96% 1.312
19 23 h 04.7 m –6° 17′ 15° Ev –1.1 5.9″ 80% 1.144
28 23 h 45.7 m +0° 20′ 18° Ev –0.4 7.4″ 44% 0.903
1 17 h 44.6 m –20° 49′ 45° Mo –4.3 19.2″ 62% 0.869
10 18 h 28.7 m –21° 13′ 44° Mo –4.2 17.8″ 66% 0.935
19 19 h 13.5 m –20° 52′ 43° Mo –4.2 16.7″ 69% 1.000
28 19 h 58.5 m –19° 44′ 41° Mo –4.1 15.7″ 72% 1.063
1 1 h 15.8 m +8° 20′ 69° Ev +0.9 6.1″ 89% 1.527
15 1 h 51.4 m +11° 58′ 64° Ev +1.0 5.7″ 90% 1.647
28 2 h 25.1 m +15° 04′ 60° Ev +1.2 5.3″ 91% 1.758
1 17 h 06.0 m –22° 14′ 54° Mo –1.9 33.6″ 99% 5.859
28 17 h 23.1 m –22° 32′ 77° Mo –2.0 36.1″ 99% 5.461
1 19 h 03.6 m –22° 11′ 27° Mo +0.6 15.2″ 100% 10.928
28 19 h 15.2 m –21° 53′ 51° Mo +0.6 15.6″ 100% 10.645
Uranus 15 1 h 48.5 m +10° 38′ 63° Ev +5.8 3.5″ 100% 20.282
Neptune 15 23 h 06.8 m –6° 44′ 19° Ev +8.0 2.2″ 100% 30.867
Sun
Mercury
28
Mars
1
15
Venus
28
Jupiter
Mars
15
Jupiter
Saturn
Saturn
15
Uranus
Neptune
The table above gives each object’s right ascension and declination (equinox 2000.0) at 0 h 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.
10"
PLANET DISKS have south up, to match the
view in many telescopes. Blue ticks indicate the
pole currently tilted toward Earth.
+40°
18 h
16 h
14 h
12 h
10 h
RIGHT ASCENSION
Vega
+30° CYGNUS
BOÖTES
HERCULES
+20°
Castor GEMINI
Pollux
4 h
2 h
0 h
Feb 19 – 20
Venus
Saturn
EC
26
Spica
Jupiter
LIP
C
TI
SAGITTARIUS
Sirius
CORVUS
ERIDANUS
HYDRA
6 am
4 am
2 am
Midnight
ARIES
Mars
PISCES
Uranus
Rigel
10 pm
8 pm
+40°
+30°
+20°
+10°
Feb 9
Neptune
Mercury
CETUS
CANIS
MAJOR
–20°
6 pm
LOCAL TIME OF TRANSIT
4 pm
2 pm
–40°
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.
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FE B RUA RY 2 019 • SK Y & TELESCOPE
0°
–30°
SCORPIUS
8 am
12
EQUATOR
ORION
Antares
–30°
TAURUS
Procyon
23
LIBRA
–10°
CANCER
Betelgeuse
VIRGO
AQUILA
10 am
Regulus
22 h
PEGASUS
Pleiades
15
OPHIUCHUS
–40°
6 h
LEO
Arcturus
+10°
0°
8 h
15
1