and Sunset Times for
Sunrise and sunset times are calculated for a flat horizon.
Actual times may vary depending upon the surrounding
landscape. The period of daylight lengthens by one hour
and four minutes during February. Twilight extends daylength
by several hours. Civil twilight provides adequate light
for movement and begins about one-half hour before sunrise.
Nautical twilight reveals shapes but not detail and begins
approximately one hour before sunrise. Astronomical twilight
illuminates the sky with a faint glow. It occurs about
one and one-half hours before sunrise. The same progression
applies to dusk.
February begins with a waning crescent moon in the early
morning twilight. On February 3, the fading crescent rises
with Jupiter and Venus in the southeastern sky along the
tail of Scorpius. On the morning of February 4 a very faint
crescent hangs directly below the two planets. After New
Moon on February 6, the moon returns to the evening sky.
On Februaary 13 a first quarter moon approaches very near
the Pleiades. On February 15 a gibbous moon moves to within
one degree of Mars after midnight. The Full Moon rises
on February 20 at 5:51 pm. A total lunar sclipse begins
at 6:00 pm. On February 25 a waning moon moves across the
sky after midnight below Spica in Virgo. On February 29
look for the last quarter moon in the southeastern morning
sky near bright orange Antares in Scorpius.
The first stage of the lunar eclipse of February 20 will
have begun by the time the full moon rises above the cliffs
surrounding Moab. However, the entire period of totality,
the 51 minutes when the moon is totally darkened by the
Earth’s shadow, will be visible as long as skies
are clear. The moon enters the partially illuminated region
of the Earth’s shadow, the penumbra, at 6:00pm as
the sun is setting in the western sky (the beginning of
civil twilight). At 6:43pm (halfway through nautical twilight)
the moon should be in full view as it begins to disappear
into the umbra, the dark central shadow cast by the Earth
onto the moon. Totality begins at 8:00pm in a dark sky
(one-half hour after the end of astronomical twilight)
and lasts until 8:51pm. By 10:09pm the moon will have moved
out of the umbra. At 11:17pm it moves out of the penumbra
and the eclipse is complete. Viewers must be east of the
Rocky Mountains to see all stages of the eclipse.
The Hyades and the Pleiades feature prominently in the winter
sky. Locate the Hyades by identifying the five stars
that form the V of the bull’s head in Taurus. Look
10 degrees (width of your fist at arm’s length)
northwest of the Hyades to locate the 6 visible stars
of the Pleiades. Although they are easily recognized
star patterns, they are not constellations. They are
known as asterisms. Asterisms may be a sub-part of a
constellation or derived from neighboring constellations.
Common asterisms include the Great Square of Pegasus,
the Big W of Cassiopeia, the Northern Cross in Cygnus,
and the Summer Triangle of Aquila, Cygnus, and Lyra.
Most asterisms are composed of stars that appear in the
same region of the sky but are not near one another in
distance. The Pleiades and the Hyades are unusual because
they are star clusters, groups of stars that move together
and have a common origin in time and space. The Hyades,
151 light years from Earth, contain several hundred stars.
At 625 million years old, these stars are only one-eighth
the age of our five billion year old sun. (Aldebaran,
the brightest star in Taurus, is not part of the Hyades
star cluster.) The Pleiades is 440 light years away with
more than 1,000 stars that formed only 100 million years
Jupiter - rises within minutes of Venus
in the early morning twilight of February 1; the two
planets appear one-half degree apart (less than the width
of your little finger held at arm’s length), their
closest approach for the year; Jupiter precedes Venus
in the morning sky for the remainder of February; located
in Sagitarius in the southeastern sky at dawn shining
brighter then most stars at magnitude -1.9.
high in the night sky throughout February,; moves eastward
through Taurus; on February 13 compare the red planet’s
color to the orange light of nearby Aldebaran; continues
to fade in brightness as Earth rapidly moves away along
its inner orbit.
visible after February 24 from a high vantage point at
morning twilight about five degrees (three fingers widths
held at arm’s length) above the horizon; in conjunction
with Venus on February 27; shines at magnitude 0.2, less
bright than Jupiter which is higher in the morning sky.
rises with Leo in the evening sky; situated near the moon
during the lunar eclipse on February 20; reaches opposition
(nearest point to Earth) on February 24 when it shines
like a full moon at magnitude 0.2, as bright as Rigel at
brilliant morning star (magnitude -3.9) can be used to
tell time throughout February; rising between 5:30 am and
5:45 am, Venus should clear the surrounding cliffs soon
after 6:00 am; in conjunction with Jupiter on February
WHY THERE ARE NO
Stars that burn hot and fast appear blue. Main-sequence stars
with average lifespans and moderate temperatures appear white
or yellow. Expanding giants and supergiants have cooler surface
temperatures and appear orange to red. The light emitted
by a star usually covers a range of wavelengths that indicates
its temperature. Any stars that emit light in the green range
would also emit light in the adjacent yellow to blue range.
The color-receptors in our eyes perceive this mix of wavelengths
as yellow to white. Use the key at the upper left of the
star chart to discover the array of colors displayed in the
CONSTELLATIONS OF FEBRUARY
The winter sky features an
array of star colors. Blue stars are Rigel in Orion,
Regulus in Leo, and major stars of the Pleiades.
White stars are Sirius in Canis Major, Procyon
in Canis Minor, and Castor, one of the twin stars
in Gemini. Pollux, the brighter twin, shines yellow-orange.
Aldebaran, in Tauras, shines orange. Betelgeuse,
at the tip of Orion’s club, shines. red.
Hold the star
chart high above your head and match the compass
directions to the direction you are facing.
Adjust the star chart by orienting Ursa Major (Big
Dipper) to match its position in the sky.
The star chart
approximates the night sky from astronomical twilight
to midnight. As the night and the month progress,
the constellations will shift toward the northwest.
Primary Sources: USGS, U.S. Naval