By Mike P. Usher
Periodically the question is asked about how a stargazer can take pictures of the night sky. To get really good pictures, it takes some thousands of dollars and a few hundred hours of practice and study; however, that being said, it’s possible to take fairly decent pictures to share among friends and family without too much trouble. To do so you need two things: a camera capable of making time exposures and a tripod. The quality of the photos depends on the size of the camera lens and sensitivity of the imaging chip.
Point the camera at an interesting area of the sky, open up the lens all the way, and trip the shutter. Start with ten seconds; that should make the planets and the brightest stars visible. You can expose your picture up to about a minute, longer than that and the stars turn into tiny streaks due to the Earth’s rotation. By all means, experiment! Old fashioned film cameras can be used, but you probably would be forced to develop and print your own film as today’s automatic processors would skip over your negatives, thinking they are blanks.
Fomalhaut is a first magnitude star in the constellation Piscis Austrinus, the southern fish, one of the original 48 constellations. In ancient times Aquarius was usually depicted as emptying his water jar into the mouth of the fish. Fomalhaut is called the lonely star as it is the only first magnitude star visible in the sky during early Autumn in northerly latitudes (but not Marco!).
Fomalhaut is a close neighbor of the Sun being only some 25 light years away. Interestingly it has a faint companion star which is easily visible in binoculars. You may wish to wait a couple of days until the too bright Moon is out of the way. Draw an imaginary line from Fomalhaut to the star at the other side of the open mouth of the southern fish. About two thirds of the way along the line there are a pair of stars – Fomalhaut’s companion is the one on the left. (The other star is nearly a thousand light years further away.) It’s an interesting lesson in the brightness range of stars; here we have two stars at virtually identical distances yet Fomalhaut is over a hundred times brighter than its companion.
As long as we are looking at this part of the sky, take a look at Grus, the crane; a noticeably brighter constellation than Piscis Austrinus. Grus is a modern constellation; in ancient times its component stars were part of the southern fish. There are no binocular objects worth mentioning in Grus.
See you next time!
Mr. Usher is President of the Everglades Astronomical Society which meets the second Tuesday each month during the summer at 7:00PM in the Books-A-Million, at the Mercato, Naples.