Opinion
Back to the Scorpion
Thursday, August 13, 2009
Let's see now, where was I? Oh yes, Scorpius. Scorpius is one of the few constellations that actually looks like what it represents, a scorpion. The three third-magnitude stars making up its head are lined up running north to south just above the southern horizon.
The fish hook or "J"- shaped body of the constellation continues south of the head almost touching the horizon then turns up and to the left completing the fish hook shape. A very clear, very flat southern horizon will be needed to observe the entire constellation because it is so low.
Just below the stars marking the head, look for a bright, reddish star marking the heart of the beast. That is Antares, the "Rival of Mars," so named for its color. A view through binoculars or a small telescope will confirm the color. When Mars passed near Antares in August of 2001 the color comparison was quite obvious.
Using your binoculars, look just below Antares for a modestly bright globular star cluster called M4. It is named so because it is the fourth object cataloged by French comet hunter Charles Messier in his famous list of things that are not comets.
Follow the line of stars down to where they turn east to make up the hook. Use your binoculars and look for what astronomy writer Terrence Dickenson calls the "Jewel Box of Scorpius." It is a really nice star cluster labeled NGC 1231. It is one of my favorites. A vast background of stars with a bright cluster in the center. It is a better sight in a telescope.
Having said that, I must say this. This Jewel Box in Scorpius is not to be confused with the other Jewel Box, NGC4755, located in the constellation Crux in the southern hemisphere. It is the brightest "star" in the constellation and without optical aid does look like just one single star. But in binoculars or a telescopes the true nature of the cluster becomes obvious.
Crux, or the Southern Cross, is near the location of what would be the south pole.
Continue along the hook until you reach the end and you will find what looks like a double star. This is the "stinger" of the scorpion, Shaula. Shaula is indeed a double star, but the pair are so close together it is impossible to separate them with amateur equipment. The other star's name is Lesath and is located 522 light years from Earth. Shaula is 709 light years from us. They are what is called an optical double.
Use your binoculars and look slightly left and above the stinger for two more star clusters, Ptolemy's Cluster. M7, and M6 the Butterfly cluster. Further up and to the left about 10 degrees will find two of the major players of the night sky, the Lagoon Nebula, M8, and the Trifid Nebula, M20. They will be in the same field of view in your binoculars as bright, slightly elongated fuzzy blobs.
SKY WATCH: Here is something to get your observing blood roused up. The moon will be occulting, covering up, the Pleiades star cluster again on Thursday. Start looking at about 2 a.m. in the east. The entire pass will last until about 5:30. Since the moon will be a small crescent, its light won't block out the view. Another conjunction will be on Sunday, with the moon and Mars getting together. Start looking at about 4-5 a.m. You can use them to find the first object Charles Messier placed in his catalog, M1, the Crab Nebula. It is a supernova remnant of a star that exploded in 1054. It is about 1 degree to the lower right of Mars. A telescope will be needed. The next morning, Monday, a thin lunar crescent will cozy up to Venus in the early morning hours. Start looking at about 5 a.m.
NEXT TIME: More astronomical blathering.