Stars over Sisters

The brilliant luminaries that shine so brightly during winter evenings are beginning to slip into the western sky, a sure sign that a change of season is at hand. To celebrate the arrival of spring, this month we are featuring the interesting constellation of Coma Berenices.

Coma Berenices (Berenice’s Hair) is a dim collection of stars located in the northern sky sandwiched between Leo on its western border and Boötes to the east. To spot it, look for the constellation’s three brightest stars Alpha, Beta, and Gamma (all shining at about fourth magnitude), that form a half square, or an inverted “L” shape. The brightest of the three is Beta Comae Berenices, a yellow dwarf main sequence star about the same size and mass as our sun, located at a distance of approximately 30 light-years.

What Coma Berenices lacks in the way of bright stars is more than compensated for by its treasure-trove of spectacular galaxies. This part of the sky contains more than 1,300 individual galaxies belonging to the northern portion of the Virgo Cluster of galaxies, plus an additional 1,000 members associated with the Coma Cluster of galaxies located much farther away.

A remarkable example of one of these objects is M64, sometimes referred to as the Black Eye galaxy. Recent evidence suggests that M64’s dark band of obscuring dust, plus the fact that the inner and outer regions of the galaxy rotate in opposite directions, can be explained by a collision between the larger galaxy and a much smaller body about one billion years ago. It is located approximately 24 million light-years from Earth.

According to sky lore, Coma Berenices is associated with the beautiful hair of Queen Berenice II of Egypt in 246 BCE. Fearful for the well-being of her husband King Ptolemy III of Euergetes as he entered an important battle, the queen promised to sacrifice her hair to the goddess Aphrodite in exchange for his safety. When the king returned home unharmed, Queen Berenice honored her vow by cutting off her hair, which was displayed in the temple of Arisone II at Zephyrium. But when the tresses disappeared the next day, the Conon of Samos, a mathematician and astronomer, claimed that Aphrodite placed her hair among the stars.

Spring in the Northern Hemisphere officially begins on Monday, March 20, at 2:24 p.m. when the sun will cross the celestial equator traveling south to north (Vernal Equinox). At this time, all locations on the earth will experience about the same amount of daylight.

The best sky show of the month will take place on the evening of March 1 when Venus and Jupiter, the two brightest planets, come into conjunction. Look for them low in the west after sunset, where they will be separated by less than one degree of arc. Still riding high among the stars of Taurus, Mars is also a prominent evening object. Although Mercury and Saturn are currently found in the morning sky, the solar system’s smallest planet will race into the evening sky later in the month.

It is difficult to overstate the significance of the cyclical effects the moon has on life here on Earth.

Our only natural satellite drives ocean tides, regulates circadian rhythms of animal life, provides varying degrees of nighttime illumination, and much more.

Humankind has learned how important it is to keep track of where the moon is in the sky.

One example of this is the custom of assigning names to the full moons for each of the 12 months of the year, which are different for various cultures and countries.

This month the full moon falls on March 7, dubbed the Full Worm Moon by Native Americans.

The Anglo-Saxons called it Lenten Moon after the Germanic Lenten for spring.

To the Celts it was the Wind Moon and Plough Moon.

In Old English, it was known as the Chaste Moon.

Become aware of how precious dark skies are to the Sisters community and learn of ways to help curb light pollution. On a clear, moonless night the canopy of stars that blaze overhead can still be awe-inspiring, but it is a sight we should never take for granted. There are many steps individuals can take to help minimize light pollution. These include closing inside drapes and blinds when it gets dark, using dimmer lights that direct light downward, turning off lights when they are not needed, and switching to warm-colored LED lights and bulbs.