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The Night Sky of March

Dr. Wayne Wooten
Professor of Astronomy

For March, the moon is new on February 26th, an annular solar eclipse for South Africa, and just six new moons until our own Great American Eclipse of August 21. On February 28th, look for the crescent moon ten degrees south of brilliant Venus in the twilight. On March 1st, the waxing crescent moon passes four degrees south of red Mars. The moon is first quarter on March 4, and passes through the Hyades cluster in the head of Taurus, occulting several of the stars that make up the "V" shape of the Bullís face.

The Full Moon of March, the "Grass" Moon, is on March 12th. The waning gibbous moon passes two degrees north of bright Jupiter on March 15th, with the bright star Spica in Virgo just south of Jupiter as well; all three rise about 10 p.m. in the southeast. The Vernal Equinox occurs at 5:29 AM CST on March 20th. On the same morning, look for the last quarter moon passing three degrees north of Saturn, both rising in the SE about 12:30 a.m. The new moon is on March27th, but note that by now, retrograding Venus has already moved into the dawn sky. However, Mercury temporarily is taking her place in the evening sky, and is visible seven degrees to the lower right of the waxing crescent moon on March 29th, with Mars five degrees north of the Moon on the same evening.

Mercury moves into the evening sky at the end of March. Venus starts the month well up in the SW and very bright. On March 1st, she is magnitude -4.6, shows a 16% illuminated crescent disk 47" wide. But as she retrogrades between earth and Sun this month, she draws closer and bigger, but a more slender crescent as seen from earth. On the 15th, she is up to 57" wide, but only 4% still sunlit, and setting right after the Sun, about 7 PM. Try spotting her thin crescent with hand held binoculars during the last weeks of March in twilight. Then on March 25th, Venus is at inferior conjunction, passing just north of the Sun into the dawn sky by monthís end.

Mars is slowing losing its race with the sun, but still visible in the SW evening sky throughout the month. Jupiter is nearing opposition on April 7th, and rising earlier in the evening sky each day in March. Small telescopes will reveal the four Galilean moons, all in a row around Jupiterís equator. The bright star of Virgo, Spica, is much fainter and just south of the giant planet this month. Saturn is now in the dawn sky in Sagittarius, and rises about 1 AM by the end of March. The rings are now tilted most toward earth and Sun, and a spectacular sight in the telescope for the rest of 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 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 South East 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. Here it sits unmoving 30 degrees high in on our northern sky locally.

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. Below the hindquarters of the lion is the "Leo Trio" of galaxie. Our photo this month shows M-65 at top left, M-66 at lower left, and almost edge on NGC 6538 at the right.

If you follow the handle of the Big Dipper to the south, by 9 p.m. 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. Spike south then to Jupiter and Spica in Virgo.

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