A circumpolar eclipsing variable with a deep (2.5 magnitude) eclipse.
The primary eclipse occurs when the fainter star in the system passes in front of the brighter star.
The eclipses are “flat-bottomed”, indicating that a total eclipse is taking place.
The orbital period of U Cephei is approx 2.493 days. Hence, if you see an eclipse on a particular night, another will be visible at a similar time of night 5 nights later.
|Extreme brightness range||6.7 – 9.3|
|More typical range||always the same|
|Period of variation||2.493 days|
|Frequency of observation||Every 30 minutes during an eclipse|
|Observe using||50mm binoculars will suffice for most of the time, but larger binoculars may be required during the deepest part of the eclipse|
|Visibility||Can be observed all year round (although there may be a spell during the spring and/or summer when no eclipses are falling during the hours of darkness)|
The following finder charts show the location of U Cephei. You can follow its brightness changes by comparing its brightness with that of the labelled comparison stars on the second chart.