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The Night Sky of June

Dr. Wayne Wooten
Professor of Astronomy
Escambia Amateur Astronomers' Association

For June 2009, the Moon will be full on June 7th, so the first week finds the moon waxing in the evening sky. This is the Flower, Strawberry, Rose, or "Honey" moon, depending on the culture. On June 13th, the waning gibbous moon will pass three degrees north of Jupiter. The Moon will be a waning crescent in the morning sky, passing 8 degrees north of Venus, then six degree north of Mars, on the morning of June 19th. New moon will be on June 22, the day after the summer solstice. The beginning of summer occurs at 12:45 AM on June 21, the longest day of the year, with about 14 hours of daylight for the Gulf Coast. The waxing crescent moon passes 6 degrees south of Saturn on June 27st, with the moon reaching first quarter on June 29th.

While the naked eye, dark adapted by several minutes away from any bright lights, is a wonderful instrument to stare up into deep space, far beyond our own Milky Way, binoculars are better for spotting specific deep sky objects. For a detailed map of northern hemisphere skies, about May 29th visit the www.skymaps.com website and download the map for June 2009; it will have a more extensive calendar, and list of best objects for the naked eyes, binoculars, and scopes on the back of the map. Also available as the next month begins is wonderful video exploring the June 2009 sky, featuring many different objects, available from the Hubble Space Telescope website at: http://hubblesite.org/explore_astronomy/tonights_sky/.

The only planet now in the evening sky is Saturn, just west of overhead. Saturn's rings are almost closed now. If the image is steady, look for the split in the two bright rings, the Cassini division, and the fainter crepe ring closer to the planet than the bright A and B rings. You may also see some belts and zones on the planet's disk. The largest, Titan, will be seen in any small telescope, but others will need larger scopes to spot. EAAA member Ed Magowan took this photo of the thin rings and disk detail in late April with a 9.25" telescope.

The winter constellations are being swallowed up in the Sun's glare, but you might spot Sirius low in the SW as June begins. Sirius vanishes into the Sun's glare by mid-June, and this sets the period as "Dog Days", when Sirius lies lost in the Sun's glare. In reality, Sirius is about 20x more luminous than our star, but also lies eight light years distant, while our star is eight light minutes away from us.

The brightest star in the NW is Capella, distinctively yellow in color. It is a giant star, almost exactly the same temperature as our Sun, but about 100X more luminous. Just south of it are the stellar twins, the Gemini, with Castor closer to Capella, and Pollux closer to the Little Dog Star, Procyon. By the end of June, all the winter stars, like Sirius, are vanished behind the Sun.

Overhead, the Big Dipper rides high. Good scouts know to take its leading pointers north to Polaris, the famed Pole Star. For us, it sits 30 degrees (our latitude) high in the north, while the rotating earth beneath makes all the other celestial bodies spin around it from east to west.

If you drop south from the bowl of the Big Dipper, Leo the Lion rides high. Saturn lies just west of the bright star Regulus, the heart of the King of Beasts. Note the Egyptian Sphinx is based on the shape of this Lion in the sky.

Taking the arc in the Dipper's handle, we "arc" SE to bright orange Arcturus, the brightest star of Spring. Cooler than our yellow Sun, and much poorer in heavy elements, some believe its strange motion reveals it to be an invading star from another smaller galaxy, now colliding with the Milky Way in Sagittarius in the summer sky. Moving almost perpendicular to the plane of our Milky Way, Arcturus was the first star in the sky where its proper motion across the historic sky was noted, by Edmund Halley.

Spike south to Spica, the hot blue star in Virgo, then curve to Corvus the Crow, a four sided grouping. It is above Corvus, in the arms of Virgo, where our large scopes will show members of the Virgo Supercluster, a swarm of over a thousand galaxies about 50 million light years away from us.

To the east, Hercules is rising, with the nice globular cluster M-13 marked on your sky map and visible in binocs. Several other good globular clusters are also shown and listed on the best binoc objects on the map back page.

The brightest star of the northern hemisphere, Vega (from Carl Sagan's novel and movie, "Contact"), rises in the NE as twilight deepens. Twice as hot as our Sun, it appears blue-white, like most bright stars. But to the south, Antares rises about the same time in Scorpius. It appears reddish (its Greek name means rival of Ares or Mars to the Latins) because it is half as hot as our yellow Sun; it is bright because it is a bloated red supergiant, big enough to swallow up our solar system all the way out to Saturn's orbit!

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