Glenn Chaple's observing basics: A view to an eclipse
November 2006: Examine Algol, Perseus' winking mystery star.
Here's a little astronomical riddle for you: Which star in the late-autumn sky winks at us once every 2 days, 20 hours, and 49 minutes? Each wink lasts about 10 hours. If you identified the mystery star as the eclipsing binary Algol (Beta [β] Persei), you're right!