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Starwatch NewsletterMinnesota Starwatch is a newsletter describing the night sky in the Midwest.
It is updated monthly, and is produced by the |
Minnesota Starwatch for June 2006
By mid-month, at 10 PM CDT, the constellation of Bootes, a kite-shaped figure with the red giant star Arcturus at the bottom, will be overhead, and Scorpio, with the bright red supergiant star Antares at its northern tip, will be just east of the meridian in the south. See if you can tell with your naked eye how extraordinarily red these stars are compared to their neighbors.
Arcturus is the second brightest star in the northern hemisphere and is a swelled-up, evolved star called a red giant. This is a phase that the sun will enter in about 5 billion years when it exhausts its hydrogen fuel in its core. At that time, the outer envelope of the sun will expand to engulf the orbit of Earth, and its luminosity will rise by a factor of 10,000. Antares is a massive star 400 light years away that has also exhausted most of its internal nuclear energy source. When its fuel becomes exhausted, sometime within the next few million years, earthlings may be treated to a spectacular sight as Antares erupts in a supernova explosion. The explosion, caused by the rapid gravitational collapse of the fuel-exhausted core, will cause Antares to become 10 billion times as luminous as the sun, and even at Earth it will appear to be twice as bright as the full moon! Within a year, the ejected shell will be big enough to be seen easily with a small telescope, and the explosion will be seen reflected off nearby interstellar dust clouds for many years. Of course, even if the explosion happened yesterday, it will not be seen on Earth until the year 2392 due to the light travel time!
For most of June the five planets Saturn, Mars, Mercury, Venus, and Jupiter will be visible. One of the more spectacular displays of Saturn, Mars, and Mercury will occur roughly an hour after sunset near June 17th low in the western sky; Saturn and Mars will be separated by less than one-half of a degree (roughly two fingers held at arms length), with the globular cluster (a collection of 1000s of stars gravitationally bound in a small region of space) M44 (sometimes known as the Beehive cluster) approximately 1˝degree to the west of the two planets. With a pair of modest binoculars, one should be able to get all three objects within the field of view! Full moon will occur on June 11th, with last quarter occurring on the 18th, thus the skies will be moderately dark when viewing this exciting arrangement of celestial sources.
Jupiter and its moons, always a nice target for binoculars, will blaze bright in the southern sky just after dust. Jupiter will be moving westward from the bright star Alpha Librae (in the faint constellation Libra, the Scales). Late in the month, after June 26th, all four Galilean moons should be visible just west of the disk of Jupiter and easily resolvable with 10x binoculars.
For the early risers at the lake cabin, Venus is a morning star all month rising in the eastern sky about two hours ahead of the sun.
Como Planetarium is offering fun family shows about astronomy on a limited basis; please call 651-293-5398 for more info!
The Minnesota Starwatch is produced by the University of Minnesota Astronomy Department.