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The Night Sky of March

Dr. Wayne Wooten
Professor of Astronomy

For March 2014, the Moon will be new on March 1st. It waxes in the first two weeks of March, and reaches first quarter, half lit in the evening sky a week later, on March 8th. Our week is in fact based on observations of the quarter phases of the moon. Sunday, March 9th finds us springing forward to CDT. On March 10th, the waxing gibbous moon passes 5 degrees south of Jupiter, well up in the NE evening sky. The Full Moon, the Grass Moon, is on March 16th, and while it misses the earthís shadow this month, it will be totally eclipsed next month, on the morning of April 15th. More on that in the April column. The waning gibbous moon is found 3 degrees south of rapidly brightening red Mars on the evening of March 19th. Contrast the color of the bright planet with blue white Spica, to the upper right of the moon 9 PM in the SE. The last quarter moon rises about midnight on March 24th.

The Spring or Vernal Equinox occurs at 11:57 AM CDT on March 20th. The waning crescent moon passes 3.6 degrees north of brilliant Venus on March 27th. The second new moon of March occurs on March 30th.

It is a great month to be observing the planets. While Mercury and Venus lie in the

morning sky, Jupiter dominates the NE evening sky, and Mars is brightening rapidly as the earth overtakes it, and rising earlier and earlier in the evening sky, and will come to opposition on April 8th, rising in the east exactly at sunset then. On March 1st, Mars rises about 9 PM, is magnitude -0.5, and appears 12" of arc across in telescopes. But as we overtake Mars, it appears to lose ground and retrogrades to the west, toward Spica, and by the end of the month, it has moved due north of Spica, risen in brightness to magnitude -1.4, and swollen to 15" of arc across. It will be better to wait to observe the planet when it is higher in the southern sky, about midnight, for the best seeing conditions to pick out the polar caps and surface detail with scopes at high magnification. This April brings Mars closer to the earth than it has been for several years.

Jupiter is bright and well up in the NE in Gemini at sunset as March begins. 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 May 10th, so those who stay up late can observe it rising in the east about 11 PM in mid March, and about 10 PM at the end of the month. The rings are tilting more open, so Saturn will be brighter this spring than last 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. The pair are associated with Jason and the Golden Fleece legend, for they were the first two Argonauts to sign up on his crew of adventurers. Jupiter sits south of the famed pair in March 2014.

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 and among the youngest known stars.

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. 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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