Continuing a Cook's Tour of constellation Scorpius

This week we continue our Cook's Tour of the constellation Scorpius.

Located in the south about an hour after local sunset, look for the distinctive backwards "J" or the fishhook shape of the constellation. The head is marked by three second-magnitude stars in a straight up and down line.

The top star is named Graffias, Arabic for the "Claw," and is a double star, a telescope is needed to split them. It is also named Beta Scorpii.

The next star down is named Dschubba and it is also a double star and slightly variable in brightness.

The next star down does not have a name, except for the one given on star charts as Pi Scorpii. It is a 2.9 magnitude eclipsing binary. That means one of the stars orbits in line with our direct sight and therefore dims Pi Scorpii when it passes in front.

The next star down the body is the bright reddish Antares, "the Rival of Mars." Binoculars show its red color, which is why the ancients' named it as Mars' rival.

Since you have your binoculars on Antares, look just to the stars right for a faint patch of stars, the globular star cluster M4, also called the Cat's Eye. It can be seen with just the eyes alone from a very dark-sky location, however, it looks best using binoculars.

The real planet Mars is just to the right of the Scorpions' head and will be in the same Field Of View (FOV) with Antares from August 21-31. So don't miss this opportunity to compare the two close up.

From Antares the body of the "Beast" continues down close to the horizon where it makes a hook to the left.

For a real astronomical treat put your binoculars on this hook.

There you will find a spectacular open cluster of stars with the rather non-interesting name of NGC 6231. It has also been called the "Northern Jewel Box," because of the variety of star colors in its members.

Binoculars work best, because a telescope will enlarge it too much and you won't get the full enjoyment of all the bright colors. It is located some 6,000 light-years from earth.

SKY WATCH: Full moon Tuesday, July 19. For a binocular-challenge, try to find the outer gas-giant planet Neptune, after 12:30 am, MDT, on Saturday, July 23, when it is about one-degree to the moon's right. It may be difficult to see the planet since the moon is just past being full, but it is a nice challenge. For another challenge, try hunting for the other outer gas planet, Uranus. After 2:30 am on the morning of July 26 start looking in the east where the moon has just risen. While the moon is dimmer, so is the planet. For a location help, put the moon at the 6:00 position in your FOV, the planet will be at the 12:00 position. Since you are in the area, look for the very nice Pleiades star cluster (M45) to the moon's lower left. These "Seven Sisters" are riding on the shoulder of Taurus, the Bull. Both are a harbinger of autumn.

NEXT WEEK: The Cat's Eyes and the Stinger, and more astronomical blathering.