Wednesday, August 28, 2013

How many stars can you see?

One of our plans that unfortunately never made it into the 1st version of the app was to provide users with feedback on how many stars they can probably see, based on their measurement. We provided a little table in the app store info, but in case you'd like something finer, here's an expanded table. Just go to your info, and find the magnitude of the faintest star you were able to see. Then check this chart to see approximately how many stars you can see in the sky:

magnitude: stars in sky
0: 2
0.5: 5
1: 8
1.3: 10
1.5: 12
1.75: 15
1.9: 20
2: 25
2.5: 50
2.89: 75
3.13: 100
3.54: 150
3.8: 200
3.97: 250
4.6: 500
4.94: 750
5.17: over 1000

In reality, you probably can't see quite as many stars as the table would indicate, because light pollution gets worse near the horizon, and the distance through the atmosphere increases, making it harder to see faint stars. But it's a reasonable rough guide.

No comments:

Post a Comment