Stars over Sisters

Perhaps the most visually impactful constellation of summer is Scorpius. There are at least two reasons for this. First, the arrangement of its brightest stars actually does resemble a scorpion, complete with claws, heart, tail, and yes, even the stinger. Secondly, because the Milky Way runs through this part of the sky, many dazzling star fields are found here.

While Scorpius can be seen on the southeastern horizon at about midnight as early as May, its full visual potential isn't on display until the months of July and August. To find the celestial arachnid this month, look about 17 degrees above the southern horizon at nightfall to find Antares, a bright, orange-colored star that denotes the scorpion's heart. You're there.

Though often referenced in modern day pop-culture, Scorpius is of ancient origin. The Babylonians were the first to recognize the collection of stars, and its given name was a result of the shape it took. Alternatively, some nautical cultures identified the pattern of stars as a longshoreman's hook. From our location here in Central Oregon, nearly all the constellation can be viewed; for latitudes north of +80 degrees none of it can be seen.

There is a plethora of lore associated with the constellation. In mythology, Scorpius was a scorpion sent by the goddess Gaia, protector of Earth, to humble the vaunting hunter Orion who proclaimed he could defeat any beast. Due to its small stature, Orion didn't spot the creature and stepped on it. While Scorpius was instantly crushed, Orion fell victim to its venom soon after.

Due to its position adjacent to the Milky Way, Scorpius is home to a wealth of spectacular deep sky objects. Globular cluster M4 was discovered in 1746 by Swiss astronomer Jean-Philippe Loys de Cheseaux. Lying at a distance of 6,000 light-years, it is the closest globular cluster to our solar system. In 1781 French astronomer Charles Messier discovered M80, a globular cluster located 33,000 light-years away. It is regarded as the densest cluster of its type.

Photo courtesy NASA/ESA/Hubble

The Butterfly Nebula is a bipolar planetary nebula located at a distance of 3,800 light-years in the constellation of Scorpius.

One of the most interesting objects in Scorpius is NGC 6302, a bipolar planetary nebula, known as the Bug or Butterfly Nebula because of its shape. A dying star that was once about five times the mass of the sun is at the center of the nebula, shedding material in its outer atmosphere into nearby space, forming a gaseous envelope. This body is about 3,800 light-years away.

Two of the year's finest events will grace our skies this month. The first is the Pereid meteor shower, which will peak on the evening of August 11 and the morning of August 12. Between 50 and 75 meteors per hour are expected. A first quarter moon sets around midnight, so it's likely observers will see more shooting stars from midnight to dawn on August 12.

Then on Wednesday morning, August 14, the planets Mars and Jupiter will come into conjunction, and appear to be separated by less than 0.3 degrees in the sky. To witness this event, face to the east between 4 and 5 a.m. The action takes place in the constellation of Taurus.

With wildfire season upon us here in Central Oregon, make the most of your stargazing opportunities! Take advantage of smoke-free nights to stargaze. If it's smoky in Sisters when the meteor shower and conjunction arrive, consider seeking out a less smoky location, if possible.

Dark Sky Tip: Use responsible lighting practices to illuminate your property at night. Excessive lighting contributes to increasing light pollution that is unhealthy to humans and animals.