Stars over Sisters

The month of May is a great time for stargazers to search out the star patterns of spring, and one of them is our featured constellation. Boötes (pronounced Bo-OH-teez; each "o' is sounded separately) is known as the Herdsman, or Plowman. It can be found in the northern sky and is bordered by Virgo to the south, Hercules to the east, and Ursa Major to the northwest. Look for a kite-shaped arrangement of stars and you will have found Boötes.

Nobody really knows the legend of the Herdsman. Some stories have said that he was the son of Demeter (goddess of the harvest), who was destined to drive the oxen of the stars across the sky. The Big Dipper is supposedly the cart. Other tales have told the story of Boötes as the inventor of the plow, who was memorialized in the stars for his ingenuity.

The most prominent object in Boötes by far is the brilliant star Acturus. Not only is it the brightest star in the constellation, it is the fourth most luminous star in the entire sky. It is thought to be about seven billion years old (about two billion years older than the sun) and currently lies at a distance of 37 light-years. To find Acturus, follow the arc of the handle of the Big Dipper. There you will find the orange-colored star.

While deep-sky objects are relatively sparse in Boötes, one of them is a globular star cluster called NGC 5548. Discovered by William Herschel in 1784, this cluster is unusual in that its stars are loosely spread out, lacking a bright, concentrated core found in many other globular clusters. This object is located 52,800 light-years from the center of our Milky Way galaxy.

The Eta Aquariid meteor shower peaks in the pre-dawn hours of May 5. This shower occurs when the earth intersects the orbit of Halley's Comet, as debris left behind by the comet enters the earth's atmosphere and is incinerated by the heat of friction. The Eta Aquariids are so named because the steaks of light appear to radiate from near the star Eta in the constellation of

Aquarius.

Although continuing to recede from the sun after its closest approach on March 10, Comet PanSTARRS can still be seen through telescopes this month and will be in the vicinity of the North Star near the end of May.

After dominating the night sky during the past several months, Jupiter now can be found low in the west after nightfall, setting at about 10:30 p.m. by mid-month. Mercury, Venus, and Jupiter will appear in close proximity to each other from May 25 through May 27. Look for them low in the western sky. Meanwhile, Saturn is ideally placed for observation this month. Almost any backyard telescope will reveal the planet's ring and its largest moon Titan.

A third-quarter moon will occur on the first day and last day of May. In between, the moon is new on May 9, at first quarter on May 17, and full May 24.

The next opportunity to view celestial objects of the night sky through telescopes is Thursday, May 9, at the Stars over Sisters star watch. The event begins at 9 p.m. at the Sisters Park & Recreation District's Coffield Center. Call Ron Thorkildson at 541-549-8846 for further information.