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The Night Sky of April

Dr. Wayne Wooten
Professor of Astronomy

For April 2014, the Moon will be new moon on March 30th. The waxing crescent moon passes 5.3 degrees south of Jupiter on April 6th. The moon is first quarter on April 7th. The full moon, the Egg Moon, occurs on April 15th, and will see the moon moving through the earthís umbral shadow between 1-4:30 AM for a total lunar eclipse. The moon will be moving through the southern portion of our shadow during the next hours and half, and start leaving the shadow about 3:30 AM. By 4:30, the moon will be moving completely out of our dark shadow.

During totality, the bright blue star Spica in Virgo to the lower right of the red moon, and much brighter Mars will be to the top right of the eclipsed moon. On April 17th, the waning gibbous moon passes 1.2 degrees south of Saturn; this will be an occultation for observers in the southern hemisphere. April 20th is Easter Sunday, late this year since the Full Moon in March happened before the Vernal Equinox, and we had to wait for the April1 5th full moon for the next Sunday to be Easter. The last quarter moon is on April 22nd, which corresponds with the Lyrid meteor shower in the morning hours. The waning crescent moon passes 4 degrees north of Venus in the dawn sky on April 25th. The new moon on April 29th will produce an annular solar eclipse, but only for a tiny region in Antarctica.

Mercury is not well placed for viewing now, but Venus dominates the dawn sky. On April 1st, she is 54% sunlit, 22" of arc across, and mag. -4.3, and by the end of the month, she pulls farther away from us, now only 16" across, down to mag. -4.1, and appears 66% sunlit. She will do behind the Sun in a few months, and return to the evening sky at the very end of this year.

Mars comes to opposition on April 8th, as the earth overtakes Mars and passes between Mars and the Sun. This is the closest and brightest Mars has been in a decade, so it will be bright red and easily visible in the SE, rising about sunset in the SE. It reaches 15" across, and mag. -1.5 at best this year.

Jupiter is still well up in the western evening sky as April begins, but gets lower in the sky and closer to the sun each evening. It lies south of the two bright stars of the Gemini, Castor and Pollux. Its four moons are a treat with any small telescope, and larger scopes will reveal a lot of detail in Jupiterís clouds, including its famed Great Red Spot.

Saturn rises in the SE about 9 PM as April begins, and reaching opposition on May 10th. The ringed wonder is at its best in the east in Libra This is the best time to observe the most beautiful object in the sky. When viewed with a telescope, the rings are open 21 degrees open, to reach their greatest tilt of 27 degrees wide at its solstice in 2017, and Titan and several smaller moons fall on either side of the most beautiful telescopic sight in the sky. In addition to its glorious rings, Saturn hosts a huge moon, Titan, visible in most any telescope, and several smaller ones needing at least a 6" scope to spot.

Yellow Capella, a giant star the same temperature and color as our much smaller Sun, dominates the northwestern 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.

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.

To the northeast, look for the Big Dipper rising, with the top two stars of the bowl, 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. Take the pointers at the front of the dipperís bowl south instead to the head of Leo, looking much like the profile of the famed Sphinx. The bright star at the Lionís heart is Regulus, the "regal star".

Now take the curved handle of the Big Dipper, and follow the arc SE to bright orange Arcturus, the brightest star of the spring sky. Recent studies of its motion link it to the Sagittarius Dwarf Galaxy, a companion of our Milky Way being tidally disrupted and spilling its stars above and below the plane of the Milky Way, much like dust falling away from a decomposing comet nucleus. So this brightest star of Bootes the Bear Driver is apparently a refugee from another galaxy!

Now spike south to Spica, the blue-white gem in Virgo rising in the SE. Mars lies a little to the west of Spica in April, and is much brighter than anything else in the SE evening sky at opposition this month. Virgo is home to many galaxies, as we look away from the obscuring gas and dust in the plane of the Milky Way into deep space. To the southwest of Spica is the four sided Crow, Corvus.

To the ancient Greeks, Spica was associated with Persephone, daughter of Ceres, goddess of the harvest. She was abducted by her suitor Pluto, carried down to Hades (going to Hell for a honeymoon!) and when Jupiter worked out a compromise between the newlyweds and the angry mother-in-law, the agreement dictated Persephone come back to the earthís surface for six months of the year, and Mama Ceres was again placated, and the crops could grow again. As you see Spica rising in the SE, it is time to "plant your peas", and six months from now, when Spica again disappears in the sunís glare in the SW, you need to "get your corn in the crib"Ö.so was set our calendar of planting and harvesting in antiquity. In the arms of Virgo is a rich harvest of galaxies for modern astronomers

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