9,096 Stars in the Sky — Is That All?

Go out on a dark night and you'd swear there are thousands of stars in the sky. Too many to count. 10,000 at least. But why guess when someone has already done the counting for you? Astronomer Dorrit Hoffleit of Yale University, well known for her work with variable stars, compiled the Yale Bright Star Catalog decades ago. It tabulates every star visible from Earth to magnitude 6.5, the naked eye limit for most of humanity.

You might be in for a surprise when you read it, though. The total comes to 9,096 stars visible across the entire sky. Both hemispheres. Since we can only see half the celestial sphere at any moment, we necessarily divide that number by two to arrive at 4,548 stars (give or take depending on the season). And that's from the darkest sky you can imagine. I don't know about you, but that number seems paltry to one's impression of an inky night in the backcountry.

At the poles, where the north and south polestars are pinned to the zenith and no stars rise or set, the same ~4,500 stars are visible every single clear night of the year. At northern mid-latitudes, the pole star is halfway up in the northern sky, allowing us to peer deeper into the southern realms of the celestial sphere. During the course of a year from latitude 45° north, we see roughly half again as many stars as we do at a particular time on a given evening. That tallies up to approximately 6,800 stars. Still pretty lean, but apparently enough to convey the impression of an intensely starry sky.
- See more at: [link to www.skyandtelescope.com]