The Sky of February

Dr. Wayne Wooten
Professor of Astronomy
Escambia Amateur Astronomers' Association

For February 2008, the Moon will be a waning crescent as the month begins. The waning crescent moon is passing about 4 degrees south of Venus and Jupiter on February 4th. The two brightest planets were only .6 degrees apart, about the diameter of the Moon, as Venus passed Jupiter in the dawn on February 1st. The new moon occurs on February 7th. The next two weeks find the moon waxing in the evening sky. First quarter moon sits high in the sky and half-lit at sunset on February 14th. The Waxing gibbous moon will be just a degree north of bright red Mars on February 16th. The full moon on February 20th is special, for it is a total lunar eclipse in the evening that the entire family can enjoy. The moon begins entering the Earth's dark umbral shadow about 8 PM, and is totally eclipsed by 9:10 PM Wednesday evening. Totality lasts about an hour, and the moon will take on a striking reddish color during this period; the blue light is scattered by our atmosphere, and the colors of sunset are refracted around the limb by our atmosphere on toward the moon. Bert Black's view of the partial phase, with the Earth's circular shadow covering about two thirds of the Moon, shows what to expect to see in binoculars about 8:40 PM. The Escambia Amateur Astronomers will host a public eclipse watch outside the PJC planetarium, starting about 7:30 until totality ends; bring along your own digital camera and take spectacular shots with our scopes and imagers.

While the naked eye, dark adapted by several minutes away from any bright lights, is a wonderful instrument to stare up into deep space, far beyond our own Milky Way, binoculars are better for spotting specific deep sky objects. For a detailed map of northern hemisphere skies, about February 1st visit the www.skymaps.com website and download the map for February 2008; it will have a more extensive calendar, and list of best objects for the naked eyes, binoculars, and scopes on the back of the map. Also available as the next month begins is wonderful video exploring the February 2008 sky, featuring many different objects, available from the Hubble Space Telescope website at: http://hubblesite.org/explore_astronomy/tonights_sky/.

Venus and Jupiter dominate the morning sky; telescopically Venus appears as a small, gibbous disk. She is now on the far side of her orbit, and will pass only .6 degrees north of Jupiter, the second brightest planet, on Febuary 1st. It was Galileo in 1611 who noted that Venus goes through this entire phase cycle, and correctly deduced this proved she orbited the Sun, not us. Covered with sulfuric acid clouds, her bright disk reveals no visible details in the scopes. He also noted the four moons, all in a row about Jupiter's equator, that orbit the giant planet. On February 1st, you may see them in the same telescope field as Jupiter and Venus at 10-40X in your telescope.

Red Mars is high overhead as darkness falls; it is much more distant and fainter than back near opposition last Christmas. It has been retrograding westward among the stars of Taurus' horns in January, but is now moving eastward into Gemini in February.

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 Pegasus'' 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 Andromeda's 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 Perseus' 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. East of Betelguese is the fine stellar nursery, the Rosette Nebula, which is our highlight photo this month. In the east rise the hunter's 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 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 over 300 years! While Sirius may appear brighter, in reality much more distant Canopus is far more luminous, about 10,000 times brighter than our own Sun, versus Sirius being only about 20 times brighter than our home star.

To the northeast, a reminder of Spring 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 Lion's heart is Regulus, the 'regal star', but brighter still is Saturn, just east and rising about 7:30 PM as February begins. On February 24, we pass between Saturn and the Sun, so Saturn rises at opposition, coming up at sunset and staying up all night. As we are then closest to the ringed wonder, this is the best time to observe the most beautiful object in the sky. More on it in March.

Read past issues of the Sky at Night