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.
