Just 35 Stars in the Sky!

You might be in for a surprise when you read it, though. To answer the question, “How many stars in the sky?” 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.

While the total number of naked eye stars may seem unimpressive, consider what happens to the sky in and around cities, where most of us live. From the suburbs, the magnitude limit is around +4 for a worldwide total of about 900 stars or half that for your location. If we set the city limit at magnitude +2 (stars similar to the Big Dipper in brightness) we’re left with just 70 stars worldwide, or 35 stars visible from say, downtown Chicago or Boston.

Friendly @physicists compiled a nice catalogue to store all the visible stars in the sky for us all to analyze in python or excel:

http://cdsarc.u-strasbg.fr/viz-bin/Cat?V/50

…and on any night, typically 2-3 of those are planets.

I still remember first viewing Saturn and Jupiter through simple binoculars and seeing some of the moons lined up across those planet’s equators.

4 Likes

I had a similar experience. Years ago for the first time seeing the rings of Saturn and watching the brighter moons of Jupiter as they changed position from one night to the next. That and visiting a dark, high elevation place in Arizona and seeing the night sky from there.

2 Likes

I have often wondered what Huygen must have been thinking when he observed Saturn changing into all sorts of shapes.

image

It’s amazing the knowledge we take for granted in today’s world.

4 Likes

Well, if the skies are clear you can see Jupiter and Saturn in the early evening tonight. Jupiter leads Saturn by roughly 30 deg currently.

1 Like