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Minnesota Starwatch

University of Minnesota

Minnesota Institute for Astrophysics

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Starwatch Newsletter

Minnesota Starwatch is a newsletter describing the night sky in the Midwest. Updated monthly, it is produced by the

Minnesota Institute for Astrophysics
University of Minnesota
100 Pleasant Street SE, Minneapolis, MN 55455

Minnesota Starwatch for August 2015

by Deane Morrison

Every August, even casual starwatchers go on the lookout for the Perseid meteorshower, and this year it should be good.

The shower is predicted to peak at 1 a.m. on the 13th, hours before the moon's harmlessly thin sliver rises through the dawn's early light. The Perseids build up to their peak slowly, so if that night is cloudy, try any early morning between the 11th and 14th. After the peak, however, they tend to drop off sharply. The meteors radiate from a point near the helmet of Perseus, which will be high in the northeast during the peak hour. Meteors will probably begin flying soon after nightfall, and under dark skies you could see as many as 50 per hour. Perseids are fun to watch because they tend to be fast and often leave persistent trails.

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On moonless evenings—between about the 4th and the 17th—the hours before midnight will be great for finding summer constellations.

Look low in the south for red Antares, the heart of Scorpius, and bright Saturn to the west, beyond the scorpion's claws. Facing west, you'll see brilliant Arcturus dragging kite-shaped Bootes, the herdsman, down toward the western horizon. Moving east from Bootes, we have the semicircle of stars known as Corona Borealis, the northern crown; the hourglass that defines upside-down Hercules; and the constellation Lyra with its brilliant star Vega, part of the Summer Triangle of bright stars. Turn your binoculars on the parallelogram of stars below Vega; this is the lyre of mythic musician Orpheus, whence the constellation's name.

East of Vega is Deneb, in Cygnus the swan, the second star in the triangle. And south of both, Altair, in Aquila the eagle, completes the triangle. Using binoculars, start with Altair and sight upwards, straight toward Vega. Not quite 40 percent of the way to Vega you'll find Brocchi's cluster, also known as the Coathanger. It hangs rather upside-down and comprises 10 stars: six in the rod of the coathanger and four in the hook.

Above Scorpius, use a star chart to make out Ophiuchus, the snake handler, and trace the snake from its head near Corona Borealis to its tail pointing to the Summer Triangle.

August's full moon comes on the 29th at 1:35 p.m., but it won't be visible till it rises around sunset. Algonquin Indians called this the full sturgeon moon, because the large freshwater fish is abundant this time of year, and also the full green corn moon.

NASA's New Horizons spacecraft performed a flyby of Pluto on July 14. As you've probably seen, the pictures show Pluto's mottled appearance, with a large heart-shaped area of light color, plus four mysterious dark, irregularly shaped and evenly spaced spots. Pluto's largest companion, Charon (named for the ferryman who carried souls over the River Styx to the underworld), has features that look like craters, chasms bigger than the Grand Canyon, and even a mountain inside a moat. Data continues to stream in, and no doubt many more discoveries are in the offing.

Duluth, Marshall W. Alworth Planetarium: www.d.umn.edu/planet

Twin Cities, Minnesota Institute for Astrophysics (during fall and spring semesters): www.astro.umn.edu/outreach/pubnight

Check out the astronomy programs at the University of Minnesota's Bell Museum ExploraDome: www.bellmuseum.umn.edu/ForGroups/ExploraDome/index.htm

07/21/15 Contact: Deane Morrison, University Relations, (612) 624-2346,

Find U of M astronomers and links to the world of astronomy at http://www.astro.umn.edu.