STARS

How to Find the Time by the Stars

Fig. 1 shows the stars around the northern pole of the heavens (Pole Star), and the Pointers of the Great Bear, which direct us to the Pole Star.

Fig. 1.

Since all stars appear to rise in the East and set in the West (which is really due to our earth turning round under them), the Pointers revolve once around the Pole Star in the opposite direction to the hands of a clock, once in twenty-four hours, or they swing through a quarter of a circle once in six hours; it is thus a simple matter after a little practice to judge what part of the imaginary circle they will pass through in an hour or less.

Assuming that all the stars rise four minutes earlier each night, and that the Pointers of the Plough are vertically above the Pole at midnight at the end of February, we may calculate the position of the Pointers for any hour of the night.

The First Twenty Stars in Order of Brightness

Date of rising at 9 P.M. in the East.
1. Sirius, the Dog-starDec. 4
2. (Canopus, of the Ship)
3. (Alpha, of the Centaur)
4. Vega, of the LyreApril 1
5. Capella, of the CharioteerAug. 21
6. Arcturus, of the HerdsmanFeb. 20
7. Rigel, of OrionNov. 4
8. Procyon, the Little Dog-starNov. 27
9. (Achernar, of Eridanus)
10. (Beta, of the Centaur)
11. Altair, of the EagleMay 26
12. Betelgeux, of Orion's right shoulderOct. 30
13. (Alpha, of the Southern Cross)
14. Aldebaran, of the Bull's right eyeOct. 2
15. Pollux, of the TwinsNov. 4
16. Spica, of the VirginMar. 1
17. Antares, of the ScorpionMay 9
18. Fomalhaut, of the Southern FishAug. 27
19. Deneb, of the SwanApr. 22
20. Regulus, of the LionJan. 1