Stars over Sisters 5/11/2022

This month we highlight the largest constellation in the 12-member zodiacal family, namely Virgo the Maiden. In fact, the only constellation that is bigger is Hydra the Female Water Serpent. Being a zodiacal resident ensures that the sun, moon, and all the planets pass through Virgo at regular intervals. Its zodiacal neighbors are Leo to the west with Libra on its eastern border.

Although the stars in Virgo are not very bright, the lone exception is Spica, which shines at a magnitude of 0.97. Here is how to find Virgo: Follow the curve of the Big Dipper’s handle down to the southeast until you come to the bright star Arcturus in Boötes. Continue the arc to the next bright star, which is Spica. There’s a mnemonic phrase to help you remember: “Follow the arc to Arcturus, then speed on to Spica.”

But Virgo is not the place to view star clusters, diffuse nebulae, or planetary nebulae, because there aren’t any. Instead, it is home to the Realm of Galaxies. Astronomers estimate that within the bowl-shaped asterism in Virgo are more than 5,000 galaxies, some of which spill northward into Coma Berenices. In Virgo alone, 11 galaxies are listed in Messier’s catalog.

Perhaps the most visually stunning galaxy in Virgo is M104, the Sombrero Galaxy. This nearly edge-on galaxy displays a bright white core encircled by thick dust lanes, likely the site of star formation. Most astronomers believe a massive black hole exists at M104’s center. This object lies at a distance of 28 million light-years.

In Greek mythology, Virgo is associated with Dike, the goddess of justice and daughter of Zeus and Themis. Because she was born mortal, she was placed on earth to rule over human justice during the Golden Age of a never-ending spring. But when Zeus defeated his father the Silver Age began with the beginning of changing seasons. Despite Dike’s repeated warnings, humans started to forget the gods. Angered by this, Dike left the earth and went to live among the stars.

Perhaps the celestial highlight of the month is the total lunar eclipse on May 15. For those of us here in Central Oregon, the eclipse begins before the moon even rises. In fact, when the moon does rise at 8:18 p.m. local time, totality will begin only 11 minutes later. The length of totality will span a full 85 minutes, with the maximum eclipse occurring at 9:11 p.m.

Jupiter and Mars will come into conjunction in Pisces on May 29.

As we already know, the Full Flower Moon will be eclipsed by Earth’s shadow on May 15. Then, from the third quarter moon on May 22 through the end of the month, the moon will vacate the evening skies and allow for taking a shot at some of those galaxies in Virgo!

Here’s this month’s dark-sky preservation tip:

Make outdoor lighting controlled. Put lights on a timer or motion sensor so they can be off when not needed or in use. Dark skies are important for ecological health. It helps with migration, seasonal changes in plants, and it supports organism health and growth.