Re: On clear night with out a telascope how many stars are visable?

G’day!
Sorry it took so long to respond, I was collecting some additional data on this subject from People Who Would Know…

How many countable stars are visible without a telescope?

Your answer would strongly depend on who you asked, but the general consensus amongst astronomers is that on a moonless night with a totally clear sky and no real light sources for at least ten miles in any direction (this means things like cities and streetlights and searchlights, more on this later) you could count between 3,000 and 5,000 stars.

Now comes the interesting part of the answer...that's right, it's a discussion!

There are a number of factors that go into that total mentioned above. How good your personal eyesight was, near- or far-sightnedness, flaws in your glasses could muck things up a little too...

Ambient light is the greatest reduction factor in stargazing, meaning the light from nearby objects such as streetlights, searchlights, and nearby cities. Not only does it lower the number of stars you can see, but the nearby light will not let your eyes become acclimatized enough to the darkness for the best stargazing.

An interesting note: There is a group called the International Dark-Sky Association which actually fights for cost-efficient and effective lighting of buildings and roads, lighting that does not destroy the dark skies needed for proper stargazing. A very good case in point is the Griffith Park Observatory in Los Angeles, California. It’s more of a museum now than an observatory, really. The light from Los Angeles, Hollywood, and the San Fernando Valley have rendered the telescope almost totally useless for anything more than viewing the Moon, Venus, Mars, Jupiter, or Saturn.

Want to know a good way to see if where you are is a good enough place for stargazing? There is a small cluster of bright stars called the Pleiades (which is surrounded by Taurus, Auriga, Perseus, Triangulum, and Aries) high up---if you can count seven of the stars, the area's good enough...if you can see a blue haze behind at least seven stars, you’re in really good shape, if you can’t see the star group, you’re not going to have a good time stargazing that night.

I hope this will help you. There are a number of very good astronomy sites on the Web that can give you more details. Two I like are: Sky & Telescope and Astronomy magazines.

Good luck!
Be seeing you,
Steve Laybourn
Camel Herder, Edmark Corporation