Galactic core · next 30 nights

Milky Way windows at Bozeman

This tracks the Sagittarius galactic core only when the Sun is at least 18° below the horizon and the core is at least 10° high. It is geometry, not a weather promise.

Best night18 Sept0.3 h of core visibility in darkness

Highest core altitude10°near 21:20

Usable nights3 / 30Moonlight and cloud still decide image contrast.

Computed local geometry

Core hours after astronomical twilight

18 Sept0.3 h54% moon

19 Sept0.3 h63% moon

20 Septnone72% moon

21 Septnone80% moon

22 Septnone87% moon

23 Septnone93% moon

24 Sept0.3 h97% moon

25 Septnone100% moon

26 Septnone100% moon

27 Septnone97% moon

28 Septnone92% moon

29 Septnone85% moon

30 Septnone76% moon

1 Octnone66% moon

2 Octnone54% moon

3 Octnone42% moon

4 Octnone31% moon

5 Octnone21% moon

6 Octnone12% moon

7 Octnone6% moon

8 Octnone2% moon

9 Octnone0% moon

10 Octnone1% moon

11 Octnone3% moon

12 Octnone8% moon

13 Octnone13% moon

14 Octnone21% moon

15 Octnone29% moon

16 Octnone37% moon

17 Octnone47% moon

21:20–21:40

This is the widest geometric window in the next month. Check the live forecast before travelling, then favor the darkest moonless portion. Check live cloud and transparency →

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Milky Way

See when the galactic core clears the horizon after dark.

−18°

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Track true darkness, including polar twilight.