Stars over Sisters

As we're finally starting to see temperatures rise and clearing skies become more frequent, there are a few celestial sights you should look for during your nightly stargazing this spring. Let's begin by locating Corvus, our featured constellation for May.

Corvus, Latin for "crow," or "raven," is a small constellation that is best seen during the first half of May. From our latitude, it will stand 25 degrees above the southern horizon at about 9 p.m. local time. Look for a misshapen square of four reasonably bright stars that lies just southwest of Virgo, a well-known border constellation. Named by the International Astronomical Union, these stars are Alchiba, Algorab, Gienah, and Kraz.

Shining at a magnitude of 2.6, Gienah is the constellation's brightest star. It is a young blue-white colored giant star that is 4.2 times more massive, and shines 355 times brighter than the sun. Gienah lies at a distance of 154 light-years.

Corvus is home to several galaxies, but none are more visually impressive than the interacting galaxies of NGC 4038 and NGC 4039. This cosmic collision is causing an exceptionally high rate of star forming activity to occur in both galaxies. Eventually these two galaxies will merge to form a single large elliptical galaxy. The galaxies are about 45 million light-years from Earth.

One mythological legend, that is commonly encountered when researching Corvus, attempts to explain why crows and ravens have their distinct black feathers. As the story goes, Corvus was originally a sacred, white-colored, bird in Greece. Apollo told Corvus to watch over one of his pregnant lovers, named Coronis, but after a while, she fell out of love with Apollo and met someone else. When Corvus told Apollo this, he became angry that Corvus didn't interfere to stop her. As punishment, Apollo cursed Corvus, turning its white feathers a charred black color.

In another story, Apollo asked Corvus to fetch water in a chalice for a sacrifice, but on the way, Corvus stopped to eat some figs. Days later Corvus returned with an empty cup, carrying a snake (Hydra) in its talons. Corvus claimed the snake took the water from the cup, but Apollo saw through the lie and in anger flung Hydra, the cup (Crater), and Corvus into the sky. The cup is kept just far enough out of reach so the bird would be forever thirsty, which is said to be why ravens and crows can't sing like other birds.

The Eta Aquarid meteor shower is active between April 19 and May 28, and peaks on the night of May 4 and predawn hours of May 5. This event is best seen from the Southern Hemisphere because the radiant is positioned higher in the sky than it is for observers north of the equator. From here up to one meteor per minute is expected. According to the May issue of Astronomy magazine, meteor rates won't exceed about a dozen per hour in the Northern Hemisphere. The good news is that moonlight will not interfere with meteor watching since New Moon occurs on May 8.

Of the five naked-eye planets, three of them will be morning objects. During the first half of the month, look to the east to see Mercury, Mars, and Saturn lined up in the predawn sky. Jupiter is the lone evening planet hovering just above the western horizon until mid-month when the sun overtakes it. Venus is too close to the sun to be viewed.

On May 23, the Flower Full Moon will arrive. So, take some time to nurture yourself and your garden that night as the moonlight is believed to have great healing energy for the body and plants.

This month, to help others enjoy these beautiful events, make sure to turn your outdoor lights off when not in use, if possible. Not only will this serve to reduce local light pollution, but it will also save you money on your electric bill!