Stars over Sisters 6/01/2021

Each year during the month of June, the sun ascends to its northern-most point above Earth’s equator. When this happens, we celebrate the beginning of summer. Take advantage of the warmer evenings to gaze into Central Oregon’s star-studded night sky, for there are wondrous sights to behold.

There is a strip of sky, centered on the ecliptic, that passes through twelve constellations. Called the zodiac, this piece of celestial real estate is where the sun, moon, and the solar system’s major planets are always found. One of these zodiacal stellar groupings of late spring/early summer is Libra.

Libra is situated just below the celestial equator between its zodiacal neighbors, Virgo to the west and Scorpius to the east. To find it start at the Big Dipper and follow the arc of its handle to the bright star Arcturus in Boötes. From here continue this arching path southward to Spica, the brightest star in Virgo. Libra lies approximately 15 degrees to the east. Look for it in the southeastern sky after dusk.

Unlike every other zodiac constellation, Libra does not represent an animal or character, but instead an object. The four major stars that comprise Libra form a sort of lopsided geometric shape, which denotes a set of weighing scales (the meaning of the word “Libra” in Latin). Libra was thought of as a balanced constellation, and the Romans associated it with steady seasons and an equal amount of day and night.

But the ancient Greeks knew this part of the sky as Chelae, or “claws,” and considered it part of Scorpius the Scorpion. In fact, the two brightest stars in Libra are Zubeneschamali and Zubenelgenubi, Arabic for the northern claw and southern claw, respectively.

Not only is Libra devoid of bright stars, but there’s a scarcity of deep-sky objects as well. The brightest of them is NGC 5897, a respectable globular cluster with a diameter of over 170 light-years lying about 40,000 light-years from Earth. The other three objects are all dim

galaxies.

This year’s summer solstice arrives on June 20 at 8:32 p.m. PDT. At that time, the sun will stand directly above the Tropic of Cancer, resulting in the longest period of daylight of the year in the Northern Hemisphere.

On June 11, Venus and a slender crescent moon will meet in Gemini, providing an attractive evening sight. Mars is there too, a little higher and farther to the east as it begins cruising through Cancer. By the end of the month both Venus and Mars will lie near the Beehive Cluster.

Saturn in Capricornus the Sea Goat rises shortly after midnight local time, while Jupiter in the neighboring constellation of Aquarius appears an hour later. Catching sight of Mercury this month will be difficult; just too close to the sun.

Early in the month the moon will be on the wane until June 10 when the new moon arrives. The face of the moon will then progressively brighten, culminating in the Full Strawberry Moon on June 24.

This month’s tip to help reduce the growing problem of light pollution in our community is to shield your outdoor lights so that the fixtures only direct light where you need it. By talking to your neighbors about what you’ve done, you will serve as an example of how to properly use outdoor lights and suggest they do the same.