Amazing Variable Star in Constellation Cassiopeiae

February 10, 2009


Provided by: Greg Parker
Summary Authors: Greg Parker, Jim Foster

The photo above is an animation of two images of open cluster NGC7789 (in the constellation Cassiopeiae), taken over a year apart, from the New Forest Observatory, Hampshire, U.K. The star sitting just below the open cluster has changed in magnitude during this period from about magnitude 7 (brightest) to approximately magnitude 14 (dimmest). This impressive variable star (WY Cas) sure appears like it’s trying to get our attention.  According to Roger Pickard of the British Astronomical Society, WY Cas does indeed vary by something like 7 magnitudes over a period of about 18 months! A change in the brightness of a star may be due to variations in the star's actual luminosity or to variations in the amount of the starlight that’s blocked from reaching Earth. So, no aliens it seems but rather an incredibly interesting object all the same. Processing by Noel Carboni, Florida U.S.