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The Night Sky of March

Dr. Wayne Wooten
Professor of Astronomy

For March 2013, the Moon will be just south of Saturn at waning gibbous on March first, rising about 9 PM. The last quarter moon rises about midnight on March 4th. Sunday, March 10th finds us springing forward to CDT. It is also perihelion for Comet PANSTARRS, which may be prominent in the evening skies for the rest of the month as it passes closest to the sun and travels almost due north into our evening skies. More on that later! The new moon occurs on March 11th, and it will be interesting to see if the comet and waxing crescent moon are both visible just after sunset in west on March 12th. The moon passes 1.5 degrees south of Jupiter on March 18th, and is first quarter the following night. The Spring or Vernal Equinox occurs at 6:01 AM CDT on March 20th. The Full Moon, the Grass Moon, occurs on March 27th. The waning gibbous moon passes 3.4 degrees south of Saturn on March 29th. Sunday, March 31st is Easter Sunday, early this year since the Paschal Full Moon occurred just after the Vernal Equinox, and the following Sunday is traditionally Easter Sunday.

It is a poor month to be observing the planets. Mercury, Venus, and Mars all lie too close to the sun for easy observing in March. Venus reaches superior conjunction, behind the Sun, on March 29th. Jupiter is bright and high overhead in Taurus at sunset as March begins, and now back in direct motion, moves eastward above the bright star Aldeberan by midmonth. Small scopes reveal its four large Galilean Moons, and larger scopes show the belts and zones on the giant planetís disk, as well as the Great Red Spot, and even shadow transits as the moons pass in front of Jupiter and casting their shadows on the planetís rapidly rotating cloud tops. Finally, Saturn is still in the morning sky in Virgo, but will come to opposition in the evening sky on April 28th, so those who stay up late can observe it rising in the east about 10 PM in mid March, and about 9 PM at the end of the month.

Hopefully Comet PANSTARRS will become as bright as Comet Hale-Bopp did in the March and April skies of 1997. The finder chart is for the latitude of Pensacola, and shows the comet in evening twilight, about an hour after sunset from March 12-22. The cometís tail will be pointing away from the Sun, and the dust tail trailing to the left as the comet rounds the sun. The brightness or magnitude of the comet is quite unpredictable, and it may be brighter or fainter than in my chart, but the cometís position should be about right based on its now well established orbit. If it is as bright as first magnitude next to the crescent moon on March 12, as shown here, it will a fine photo opportunity for anyone with a digital camera, tripod mounted, set in night shot mode. Even at second or third magnitude later in the month, its tail should be a nice object to observe with binoculars for the rest of March and into April. But an even brighter comet is heading toward us in 2013 as well. Some expect Comet ISON in the December morning skies to become the best and brightest comet seen by anyone alive today. So letís hope that PANSTAARS is a nice opening act for an even greater spectacle later this year!

The constellation Cassiopeia makes a striking W in the NW. South of Cassiopeia is Andromedaís hero, Perseus. 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 in the northwest. 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; it is directly above us as darkness falls in early March. 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 southern 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 are 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 as darkness falls. 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, look for the bowl of the Big Dipper rising, with the top two stars, the pointers, giving you a line to find Polaris, the Pole Star. Look for Mizar-Alcor, a nice naked eye double star, in the bend of the big dipperís handle, rising by 7 PM at the start of March. If you take the pointers of the Big Dipperís bowl to the 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". The folk wisdom that "March comes in like a Lion" probably refers to the head of Leo rising just after sunset in early March.

If you follow the handle of the Big Dipper to the south, by 9 PM you will be able to "arc to Arcturus", the brightest star of Spring and distinctly orange in color. It color is an indication of its uniqueness. It large speed and direction through the Milky Way suggests it was not formed with our Galaxy, but is a recent capture from the Sagittarius Dwarf Galaxy, a smaller satellite galaxy now being assimilated by our huge spiral galaxy. Many of its lost stars, like Arcturus, follow a band across the sky at about a 70 degree angle to our galactic plane. Arcturus is at the tail of kite shaped Bootes, the celestrial bear driver chasing the two bears from his flocks.

By 9 PM, many more galaxies will be following as the Virgo Supercluster, just above Saturn now, rises in the east. This huge cluster of over a thousand galaxies is centered about 60 million light years away. The brightest star of Virgo, Spica, lies just east of the center of the cluster, and its rise just after sunset marks the time of year for spring planting in folklore. Time to get your peas in the groundÖ.

March goes out like a lamb, not just from Easter tradition, but because Aries the Ram is setting in the west by the end of March. Many of our sayings and traditions have astronomical origins.

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