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Sky Test

StarDate: 
June 30, 2013

The planet Saturn will snuggle close to a faint star over the next couple of weeks. Trying to find the star will tell you how dark your skies are.

As long as the sky is clear, you shouldn’t have any trouble at all finding Saturn. It’s about halfway up the southern sky at nightfall, and glows with a slightly golden hue. It outshines all but one other planet and two stars at that hour.

The star Kappa Virginis stands just above Saturn. Unlike Saturn, though, it’s so faint that you need a dark sky to see it.

Astronomers measure the brightness of planets and stars with the magnitude scale, in which brighter objects have smaller numbers. Right now, Saturn shines at a magnitude of 0.5. Kappa Virginis, on the other hand, is at about 4.2 — just three percent as bright as Saturn.

If you live in the center of a brightly lit city, there’s almost no chance that you’ll see Kappa Virginis. The glow from city lights overpowers all but a handful of stars and planets. You might be able to see the star from a relatively dark suburb, but you’ll need to find a spot with no streetlights or porchlights and give your eyes some time to adjust to the darkness.

The best view comes from a dark country location with no artificial light sources at all. Under these conditions, a person with especially good eyesight can see stars down to sixth or seventh magnitude — just a fraction of a percent as bright as Saturn — a planet that’s a brilliant target under any skies.

 

Script by Damond Benningfield, Copyright 2013

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