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The Night Sky of February

Dr. Wayne Wooten
Professor of Astronomy

For February 2015, the Moon will be full moon on February 3rd; this is the "hunger" moon in Native American tradition, when most of the food stored up for winter was almost gone. The next evening, look for the waning gibbous moon to be five degrees south of bright Jupiter, rising just after sunset. Jupiter comes to opposition on February 6th, rising in the NE exactly at sunset.

The last quarter moon passes 2 degrees north of Saturn on the morning of February 12th. New Moon is on February 18th. By the 20th, the waxing crescent moon is passing 2 degrees north of brilliant Venus in the SW twilight, and it passes 1.5 degrees north of Mars the following evening. The first quarter moon is on February 25th, and it passes just north of the bright star Aldebaran in Taurus as twilight falls; in South America, it will cover the star in an occultation taking about an hour.

Mercury is low in the morning sky by monthís end, reaching greatest western elongation on February 25th. Venus dominates the SW evening sky for the next several months, and is rapidly overtaking much fainter red Mars, passing just a moonís diameter south of him on Feburary 22nd, with the crescent moon closest to the pair on the previous evening; sounds like a great photo op! Jupiter dominates the eastern evening sky, coming to opposition on the border of Cancer and Leo on February 6th.

Our photo this month show the moon Io passing in front of Jupiter, with the Great Red Spot also visible. Any telescope can show the four Galilean moons, and the belts and zones and Great Red Spot show up at 100X in larger scopes as well. Saturn is now in the claws of Scorpius, and rising about midnight by monthís end. The ringed planet will be coming to opposition on May 23rd. The rings are much more open than last year, and are open about 22 degrees now, compared to 27 degree when fully opened at Saturnís solstice in 2016; when this open, the huge reflecting surface of the ringís ice boulders will double the planetís brightness.

The constellation Cassiopeia makes a striking West in the North West. She contains many nice star clusters for binocular users in her outer arm of our Milky Way, extending to the North East now. Her daughter, Andromeda, starts with the North East corner star of Pegasusíí Square, and goes North East 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 West 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 minutes before Sirius, the brightest star in the sky. 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.

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". Note that Jupiter now sits just west of the head of Leo, and will be moving from Cancer into Leo by mid year.

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