Algol, the brightest and most famous eclipsing binary star, will go into eclipse Monday night, the evening of Jan 27.
At 9:46pm EST, it will be shining at 3rd magnitude, three times fainter than its usual brightness outside eclipse.
Algol is the lower vertex of a celestial triangle formed with the planet Jupiter and 1st magnitude star Capella above it.
This online Stellarium chart shows Algol in relation to Jupiter and Capella. To use the chart, face to the northwest.
Eclipses happen every 2.87 days. To watch Algol fade from normal brightness, start around 7pm or so.
