By Mike P. Usher
Tonight the two brightest constellations in the zodiac are rising high in the south. Sagittarius is associated with a centaur carrying a bow, while Scorpius is a scorpion of course. These two constellations lie in the direction of the center of our galaxy, and as a consequence this area is almost literally stuffed with clusters and nebulas.
The chart tonight shows deep sky objects down to 8th magnitude – within the range of 9×50 binoculars. A dotted circle shows the location of an open cluster, a circle drawn with a solid line is a nebula, perhaps with a star cluster associated with it. A circle with a cross inside marks the spot of a globular cluster. Brighter objects tend to have names and Messier catalog numbers, fainter objects tend just to have an NGC number. A handful are bright enough to see with the naked eye as faint hazy patches hardly distinguishable from the Milky Way. Although the dwarf planet Pluto is labeled (just to be complete), there is no chance at all of spotting it even with your binoculars. It’s only visible in a very large amateur telescope by a observer holding a detailed star chart.
For the stargazer without binoculars this region is still full of visual treats. Scorpius is one of a handful of constellations that actually look like the object they are supposed to represent, in this case a scorpion. Antares looks like the red heart of a scorpion – or perhaps an eye staring back at you. Neighboring Sagittarius contains a famous easy to see asterism, a teapot made up of roughly equally bright stars. The exact center of our galaxy is just to the right of the teapot’s spout although our view is blocked by many large clouds of dust that infest this region.
The Milky Way itself is at it’s brightest and broadest point in this region. At a dark sky site you can see it suddenly flare to perhaps twice it’s normal width. In a long exposure photograph, of perhaps a minute, you can see the great central bulge of our home galaxy obscured here and there by dust clouds.
Mr. Usher is President of the Everglades Astronomical Society which meets the second Tuesday each month at 7 PM in the Norris Center, Cambier Park, Naples.