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The Night Sky of June

Dr. Wayne Wooten
Professor of Astronomy

For June the waning gibbous moon passes 1.6 degrees north of Mars in the morning sky on June 3rd. Look how bright Mars appears this morning, and then wait a month until the moon passes above Mars again on July 1st. By then, the earth is overtaking Mars, making it much closer, bigger, and brighter than it appears this morning. It will be more than twice this bright in July! The moon is third quarter on June 6th, and new on June 13th. On June 15th, the waxing crescent moon is to the lower right of brilliant Venus in evening twilight, and by the 16th, it lies just to the upper left on Venus. So the afternoon of June 16th, if it is clear, will be a fine time to catch Venus and the moon in afternoon daylight, about 30 degrees east of the Sun.

The moon is first quarter on June 20th. June 21st is the summer solstice, the longest day, about 14 hours in Pensacola, and even longer at more northern latitudes. This event occurs at 5:07 AM CDT, and marks the northernmost point of the Sun on the ecliptic as we revolve around it annually. The waxing gibbous moon is just north of Jupiter on June23rd, another chance to catch a planet in daylight if the skies are clear enough in late afternoon. Jupiter is fainter than Venus, so this is a far more difficult challenge, but I have done it a few times. The full moon, the Honey Moon, passes just north of Saturn on June 28th, and returns to pass north of Mars again at month’s end. Again, look at how much brighter Mars appears than on June 3rd!

This June Mercury is too close to the sun to observe. Venus dominates the western evening sky, and should be easily found in daylight on June 15th, letting the crescent moon guide you. Telescopically it is a gibbous bright disk, 80% sunlight now. No other details are noted with amateur scopes alas. Mars is in Capricornus, rising in the east at about midnight at the start of June, and around 11 PM by month’s end. Its disk is still small, but getting bigger and brighter by night as the Earth overtakes it. The two planets are closest and brightest at opposition on July 26th, when Mars rises at sunset. We have note seen Mars this close since August 2003.

Jupiter is well placed for evening observers in Libra. It was at opposition on May 5th, and is now weel up in the SE as twilight falls. Any small scope will also spot its four Galilean moons. The Great Red Spot is unusually red now, and should also be spotted among its clouds at 100X with even small scopes. But the most beautiful object in the sky is Saturn, which comes to opposition in Sagittarius on June 27th. Look closely for its large moon Titan, and also perhaps for smaller moons Dione, Rhea, and Tethys. Download the program Stellarium at www.stellarium.org and you can zoom in on the planets to find the layout of the moons of Jupiter and Saturn at any moment.

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. 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.

Spike south to Spica, the hot blue star in Virgo (with Jupiter now to its upper right), 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. This rich cluster is one of the top telescopic sights in good sized scopes. 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 rises in the NE as twilight deepens. Twice as hot as our Sun, it appears blue-white, like most bright stars. Its constellation, tiny Lyra, looks like a parallogram just south of Vega, but was the harp of Orpheus in Greek legends.

In the southeast, Antares rises about the same time as Vega does, in the brightest of all constellations, Scorpius. Antares appears reddish (its Greek name means rival of Ares or Mars to the Romans) 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! Saturn lies north of the stinger tail of Scorpius, on the border of the teapot shape of Sagittarius rising in the SE after sunset.

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