Gemini's twin stars dominate April's skies
POSTED: Tuesday, April 06, 2010
If you have been following along with this monthly column, you should be able to identify the constellations of Orion, Taurus and Leo. This month's highlighted constellation is Gemini, the Twins. Gemini can be found to the north of Orion, in between Taurus and Leo. Gemini is visible throughout the month in the evening sky. Look for the bright twin stars Castor and Pollux high in the western sky after sunset, then watch them slide toward the horizon as the evening progresses.
In Greek mythology, Castor and Pollux were identical twin brothers with a unique difference: Pollux was immortal while Castor was human. This came about because their mother had already conceived Castor with her mortal husband when the god Zeus impregnated her with the immortal Pollux. The twins had many adventures, including one that ended in Castor's death. Devastated at the loss of his brother, Pollux begged Zeus to make him mortal. Zeus allowed the twins to be together forever as stars in the sky.
In Hawaiian these stars are sometimes called Na Mahoe, meaning “;the twins.”; The stars Castor and Pollux are used in Hawaiian celestial navigation and are part of the “;Canoe Bailer of Makalii”; star line.
The Gemini North Observatory on Mauna Kea is named after the Gemini constellation. Gemini North has a twin telescope, Gemini South Observatory, in Chile. Both are 8-meter optical/infrared telescopes that can collectively observe the entire sky. The part of the sky that is not visible from Hawaii can be seen in Chile, and vice versa.
VISIONS OF VENUS
Venus blazes in the evening sky throughout April. At an apparent magnitude of 3.91, Venus is brighter than any natural object in the sky other than the sun and moon. Look toward the west after sunset and you can't miss this beautiful planet. Venus and Mercury can be seen close together at the beginning of the month. After Saturday, Mercury moves steadily toward the horizon and then disappears from view. Try to observe the thin crescent of the waxing moon in between Mercury and Venus just after sunset on April 15. The next night the moon pops higher in the sky, only about four degrees away from Venus. On April 24 enjoy the sight of the Pleiades in conjunction with Venus.
LYRID METEOR SHOWER
Early risers might enjoy observing this year's Lyrid meteor shower since the peak occurs before dawn on the morning of April 22. Meteors also might be visible late on the night of April 21, but the waxing gibbous moon will provide some light competition until it sets at 1:47 a.m. The Lyrids typically aren't one of the year's best meteor displays, but a careful observer might see as many as 20 meteors an hour during the peak time.
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Nancy Alima Ali manages the Hokulani Imaginarium at Windward Community College. E-mail your comments or questions to .(JavaScript must be enabled to view this email address). For a schedule of Imaginarium offerings, visit aerospace.wcc.hawaii.edu/imaginarium.html.