Roughly how many stars are clearly visible to the naked human eye on a clear night in the northern hemisphere?

Answer 1

About 4 thousand more or less.

Answer 2

The limit of visibility for the human eye is usually taken to be magnitude 6.0, although this can be much less for those with poor vision, and a little better for those with exceptional vision. But given that value, and after combining double stars, there are a total of 5034 stars in the celestial sphere of mag 6.00 or brighter, according to the Yale Bright Star Catalog. (There are 9096 entries in the whole catalog, but many of those are dimmer than 6.00, and many are doubles.)

Given that about half are below the horizon at any one time, that would leave about 2517 stars above the horizon, at mag. 6.0 or brighter -- IF the Earth had no atmosphere.

But of course that's not the case. In fact, the Earth's atmosphere absorbs some light no matter how clear it is. If we assume the absolutely ideal case -- zero aerosols, which means no dust, no vapor, no cloud droplets at all -- the remaining atmosphere still absorbs about 0.13 magnitudes per airmass. When you look straight up, you're looking through 1 airmass; at an altitiude of 30°, you're looking through 2 airmasses; and right at the horizon, you're looking through about 38 airmasses.

So at a minimum, after accounting for atmospheric extinction, you could only see a star with a pre-extinction magnitude of 5.87 or brighter in the ideal case (at the zenith). That takes us down to 4398 stars in the celestial sphere right there. And most stars are not on the zenith; the average star is seen through 2 airmasses, which would allow only stars with magnitudes of 5.74 or brighter to be seen. That takes us down to 3763 stars in the celestial sphere. Of those, about half would be below the horizon, so the final answer is:

Roughly 1881 stars visible with the naked eye at any one time, under ideal conditions.

Thanks for an interesting question. Starred.

Answer 3

There are only 9096 stars which can be seen with the naked eye, and at any given time about half of them are below the horizon.

Answer 4

If you are going to look from a dark countryside, then you will see around 3000 or something and if from townside,

around 100.

Answer 5

2000 to 2500

Answer 6

stars change position, even in the northern hemisphere, so the answer is rough. thousands to say the least.


you know, after all the books i read, i never found that tidbit of information. thanks for piqueing my interest

Answer 7

Count them yourself because there are many stars that are born every minute . Roughly , there are 797,234,146,074 million stars according to 2007 census .There are about 4 million stars per person . So, check the population and multiply it with 4 million.

Answer 8

I think it depends on how close you are to a big city.

Answer 9

hundreds and maybe if you were far from civilization, a few thousand

Answer 10

there are about sextillion star in the universe i don't know how many u can see 1,000,000,000,000,000,000,000