February opens with the winter constellations well-placed in the sky as darkness descends. Brilliant stars abound in mid-winter, dominated by Sirius, the brightest star in the night sky. In early February, 11 of the brightest 25 stars in the entire night sky are visible around 9pm MST (8pm MST in late February).
Once darkness sets in, the Orion and Perseus arms of our galaxy, appear as a faint, narrow cloud of stars, spanning the sky from the northwest to the southeast horizons, passing through numerous constellations, including Cygnus, Cassiopeia, Perseus, Auriga, Gemini, Orion, Monoceros, Canis Major, and Puppis.
While not as glorious as the ‘summer Milky Way’ (located toward the center of our galaxy), the winter Milky Way is still a sight to behold on a dark night and one that can’t be enjoyed by many in the US, due to light pollution.
February Night Sky Spotlight:
Orion is one of the most well-known constellations in the sky, named for a hunter in Greek mythology. This month, it’s visible for much of the night.
Orion’s body is depicted by a large rectangle of bright stars. The lower right star is the blue-white Rigel, the seventh brightest star in the night sky.
Diagonally opposite Rigel is red-orange Betelgeuse, marking one of Orion’s shoulders. Betelgeuse is known
as a semi-regular variable star, meaning that its brightness waxes and wanes over a somewhat predictable period. A bright star in its own right, Betelgeuse varies between being the fifth and 23rd brightest star in the night sky.
Betelgeuse is a red giant, a cooling star that‘s burned through its hydrogen and is nearing the end of its stellar life. If our Sun was replaced by swollen Betelgeuse, the Earth would not exist because Betelgeuse’s width would extend to the orbit of Jupiter.
Two years ago, Betelgeuse was in the news because it dimmed significantly and then didn’t brighten when expected (it has since returned to ‘normal’ behavior). The prevailing theory is that the dimming was caused by a large dust cloud, expelled from the star.
In the middle of the rectangle depicting Orion’s body are three fairly bright stars forming a rough line. This is Orion’s belt. A line extended downward from the belt stars roughly points to dazzling, blue-white Sirius. A line drawn in the opposite direction roughly points to red Aldebaran, the brightest star in neighboring Taurus.
Just below Orion’s belt is his sword, consisting of a compact row of four ‘stars.’ The brightest of these appears indistinct. It’s not a star, it’s a giant cloud of dust and gas, known as the Orion Nebula. The nebula is a stellar birthplace of about 700 stars.
Above Betelgeuse is a group of faint stars that form Orion’s club-wielding right arm. A portion of the Milky Way runs through the upraised arm and club. Beginning at Orion’s opposite shoulder (the star Bellatrix), is a faint curving line of stars that denotes Orion’s shield (some artist renderings show Orion holding an animal pelt instead of a shield). A compact triangle of stars between and just above Betelgeuse and Bellatrix marks the hunter’s head.
February Night Sky Planets:
The plethora of planets seen earlier this winter have, for the most part, departed the evening sky. Mars is still visible in Aries after dark, but it’s noticeably fainter than it was several months ago, since the distance between Earth and Mars is increasing.
At the beginning of February, Venus, Saturn, and Jupiter create a short conga line, but are difficult objects to find in the brightening dawn. By month’s end, Saturn and Jupiter have moved farther west of the Sun and are easily viewed in the early dawn, joined by elusive Mercury. Venus has moved closer to the Sun and isn’t visible.
February Night Sky Events:
February 5: Midwinter.
February 10: The waning crescent Moon joins Saturn, Jupiter, Venus, and Mercury in Capricorn, in the ESE, just before sunrise. Binoculars will be needed to find these objects in the strong glare of dawn.
February 11: New moon.
February 18: The first quarter Moon passes just below Mars in the constellation Aries. Notice how the Moon pulls away from Mars as the evening progresses. The two objects will be visible until they set together, just after midnight.
February 24: The waxing gibbous Moon passes close to the Beehive Cluster in Cancer. Binoculars will be needed to view the open cluster in the strong moonlight.
February 27: Full moon occurs at 1:19am MST in the constellation Leo.
– Eric Saltmarsh