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The Night Sky of February

Dr. Wayne Wooten
Professor of Astronomy

For February 2017, the Moon will be first quarter on February 3rd. The moon is full on February 10th. In native American tradition, this is the "hunger moon", when almost all the stored harvest had been depleted.

The waning gibbous moon passes 3 degrees north of bright Jupiter on February 15th, with both rising about 10 PM in the SE. The last quarter moon rises about midnight on February 18th. The waning crescent moon passes four degrees north of Saturn in the dawn on February 20th. The moon is new on February 26th, and passes in front of the sun for those in South Africa, but we will have to wait until August 21, 2017 when the new moon will cover 82% of the Sun as seen from Pensacola at 1:37 PM CDT. The waxing crescent moon makes a fine pair with brilliant Venus at dusk on February 28th, with Venus ten degrees north of the moon.

Mercury is too close to Sun for easy observing this month. Venus dominates the evening sky for the next few weeks, but will be lost in sunís glare soon. It gets bigger in the telescope as it overtakes Earth, but the phase changes from 40% sunlit on February 1 to only 17% crescent at monthís end. Mars was overtaken by faster moving Venus at the end of January, and is getting lost in the sunís glare by monthís end. Jupiter dominates the late evening eastern sky, and passes 4 degrees north of Spica in Virgo on February 23rd. The ringed planet Saturn will be coming to opposition on June 15nd, and is now north west of the teapot of Sagittarius in the morning sky. Itís rings are open about 27 degrees now, fully opened at Saturnís solstice this year; when this open, the huge reflecting surface of the ringís ice boulders will double the planetís brightness.

The constellation Cassiopeia makes a striking W in the NW. She contains many nice star clusters for binocular users in her outer arm of our Milky Way, extending to the NE now. Her daughter, Andromeda, starts with the NE corner star of Pegasusíí Square, and goes NE with two more bright stars in a row. It is from the middle star, beta Andromeda, that we proceed about a quarter the way to the top star in the W of Cassiopeia, and look for a faint blur with the naked eye. M-31, the Andromeda Galaxy, is the most distant object visible with the naked eye, lying about 2.5 million light years distant. Overhead is Andromedaís hero, Perseus, rises. Between him and Cassiopeia is the fine Double Cluster, faintly visible with the naked eye and two fine binocular objects in the same field. Perseus contains the famed eclipsing binary star Algol, where the Arabs imagined the eye of the gorgon Medusa would lie. It fades to a third its normal brightness for six out of every 70 hours, as a larger but cooler orange giant covers about 80% of the smaller but hotter and thus brighter companion as seen from Earth.

At Perseusí feet for the famed Pleiades cluster; they lie about 400 light years distant, and over 250 stars are members of this fine group. East of the seven sisters is the V of stars marking the face of Taurus the Bull, with bright orange Aldebaran as his eye. The V of stars is the Hyades cluster, older than the blue Pleiades, but about half their distance.

Yellow Capella, a giant star the same temperature and color as our much smaller Sun, dominates the overhead sky. It is part of the pentagon on stars making up Auriga, the Charioteer (think Ben Hur). Several nice binocular Messier open clusters are found in the winter milky way here. East of Auriga, the twins, Castor and Pollux highlight the Gemini. UWF alumni can associate the pair with Jason and the Golden Fleece legend, for they were the first two Argonauts to sign up on his crew of adventurers.

South of Gemini, Orion is the most familiar winter constellation, dominating the eastern sky at dusk. The reddish supergiant Betelguese marks his eastern shoulder, while blue-white supergiant Rigel stands opposite on his west knee. Just south of the belt, hanging like a sword downward, is M-42, the Great Nebula of Orion, an outstanding binocular and telescopic stellar nursery. The bright diamond of four stars that light it up are the trapezium cluster, one of the finest sights in a telescope.

In the east rise the hunterís two faithful companions, Canis major and minor. Procyon is the bright star in the little dog, and rises before Sirius, the brightest star in the sky. Midway between them is the fine Rosette Nebula, a great Valentineís present for your beloved.


The Rosette Nebula

Sirius dominates the SE sky by 7 PM, and as it rises, the turbulent winter air causes it to sparkle with shafts of spectral fire. Beautiful as the twinkling appears to the naked eye, for astronomers this means the image is blurry; only in space can we truly see "clearly now". At 8 light years distance, Sirius is the closest star we can easily see with the naked eye from West Florida.

When Sirius is highest, along our southern horizon look for the second brightest star, Canopus, getting just above the horizon and sparkling like an exquisite diamond as the turbulent winter air twists and turns this shaft of starlight, after a trip of about 200 years!

To the northeast, a reminder that spring is coming; look for the bowl of the Big Dipper to rise, with the top two stars, the pointers, giving you a line to find Polaris, the Pole Star. But if you take the pointers south, you are guided instead to the head of Leo the Lion rising in the east, looking much like the profile of the famed Sphinx. The bright star at the Lionís heart is Regulus, the "regal star". Fitting for our cosmic king of beasts, whose rising at the end of this month means March indeed will be coming in "like a lion".

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