Algol
Algol, also know as Persei (26), HR936, HD19356, SAO38592,
at R.A.= 3h08m, dec=41° is an eclipsing
binary star.
Algol's magnitude is typically 2.1, but every two days, 20 hours and 49 minutes
it dips to 3.4 for about 10 hours.
Perseus
In the below Wiki image, the red arrow marks the location of Algol in Perseus.
