Astronomy: July is the season of Scorpius – Longmont Times-Call

Posted: July 2, 2017 at 9:54 am

(Daniel Zantzinger / Skywatcher's Guide)

It is perhaps indisputable that skywatching July's warm summer nights is the most comfortable, spectacular and awe inspiring outdoor activity going.

The trick, the essence of summer's night skywatching, lies in first rooting in the core concentration of stars in the south, and then slowly climbing the galactic arms toward zenith and beyond.

Whether you're using your eyes, binoculars, telescopes, scientific journals and/or telescope-directing websites, there's more than enough out there to stimulate the imagination, provoke wonder and astound the senses.

For many skywatchers, this is a great time to head away from the city lights into the hills; to the high country with its deep and darkened valleys; to our state parks and national monuments; and to someone else's sparsely populated, protected properties.

This is the season of the scorpion, the swan, the deeply troubled Hercules and myriad other sidereal (star-like) residents of the Milky Way. Moreover, each one of these house crystalline and nebulous denizens of their own, who in turn hold in their embraces secrecies unfolded only to skywatchers making the effort to look for them.

Find fishhook-shaped Constellation Scorpius, "the scorpion," low and due south at 11 tonight (July 1) and around nightfall on the 31st. To its east is teapot-shaped Constellation Sagittarius, "the centaur archer," and to its north is Constellation Ophiuchus, "the serpent-bearer." Saturn, having reached opposition just two weeks ago, is well positioned here for viewing until the end of August.

These areas of space are so rich that if you figuratively speaking were to draw your last breath right after careful and thorough examination of them, you will have died having a life fulfilled with few regrets.

The moon is bright here in the month's first 10 days or so, so it's best to get serious July 16 and thereafter.

Darker skies mean better views. Longer expanses of time between ocular exposures to white light after a minimum of 12 minutes mean better viewing ability. Use red flashlights. Avoid looking at car headlights, or you'll have to start the clock all over again. A good dose of Zen patience and measured breathing provides for you a better overall experience. Speak minimally, and your companions will have a better overall experience.

When you're staring at Sagittarius, you're gazing in the direction of the galactic core, that is, toward the center of the Milky Way. Most of the wow factor in the southern sky is from here toward zenith.

From our line of sight, three arms of the spiral barred (striped) galaxy intersect at the Scorpius/Sagittarius border. This allows us to observe not only millions of stars, but also diffuse nebulae M8, M17 and M20; and the relatively young and open star clusters M6, M7, M21, M23 and M25 circulating with the disc. These clusters have a few hundred to several thousand stars.

Scorpius and Sagittarius and our southern sky's hemisphere for that matter is home to an abundance of globular star clusters, spherical concentrations of several hundreds of thousands of much older and denser stars that dwell in the galaxy's outer halo.

With the naked eye, find red giant star Antares, the "rival of Mars," the heart of the scorpion, an irregular star that slowly pulses from magnitude 0.6 to 1.6. Train the telescope 1.3 degrees west to M4 to find one of the two closest globular clusters to the solar system.

Clocking in at 12.2 billion years old, M4 has some 13 billion-year-old white/degenerate dwarf stars invisible to earthbound skywatchers that are among the oldest known stars in the Milky Way galaxy. In 1995, the Hubble Space Telescope photographed white dwarf PSR B1620-26 with a planet with a mass of 2.5 times that of Jupiter.

With binoculars and/or a motorized telescope, crawl up the galaxy's arms into Constellation Cygnus, "the swan,"to the Great Globular Cluster (M13) in Constellation Hercules at zenith, and then into the great beyond.

The moon is full at 10:07 p.m. July 8, and is called the Full Thunder Moon.

The rest is here:

Astronomy: July is the season of Scorpius - Longmont Times-Call

Related Posts