Seeing Stars

If you do not have clouded skies tonight you might be able to see lots of stars. Like Daniel who is camping somewhere in Utah. In fact, he should be able to see seven stars in the little dipper. It is available all year to any of us in the northern hemisphere. Catalina, in Oakland, will not have such great seeing. Perhaps two or three stars in the little dipper. It, seeing the number of stars you can count in the little dipper is a quick and easy measure of “seeing”, a quality measurement for the night sky. It helps to go look and count after you have been in the dark for a while. Twenty minutes or so. Years ago I used to give annual talks on “seeing” and how to judge it. Amateur astronomers are very interested in the quality of the skies they are looking through when looking for the “dim and fuzzy” items in the sky. Each region of the sky will have groups of stars with defined boundaries. They are defined by known, bright stars. Count the stars in the group and all the stars you can see inside the triangle or box and you will have an index to the quality of the sky. This does vary by what part of the sky you are looking at or the distance between the horizon and the zenith. The absolute amount of darkness is one measure of the night’s seeing. There is the amount of steadiness, what gives stars their twinkling.

If you like to look at stars, you are, unfortunately, hosed. An image of the USA from the sky, say from the view of a satellite or the International Space Station, you can see so much light leaking from the ground that you can recognize cities, interstate highways, and precious few dark places.

I am waiting for it to get dark to see what I can see of the little dipper. And … I saw zero stars. It is cloudy outside tonight. Hopefully, you can if you have seen see at least a couple or three.

— MichaelRpdx

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