This is NGC 2362, an open cluster in Canis Major. The cluster has also been given the odd name of “The Mexican Jumping Star”. The bright star at the center is Tau Canis Majoris a 4th magnitude double variable star. It is an eclipsing binary, which means the two stars orbit around one another and the brightness varies as the stars of different brightness pass in front of each other, from our perspective.
This was taken with a full moon only about 30 degrees away, rising in the eastern sky. I was also trying out my AutoGuiding system on my 125mm Orion Refractor, which worked out just fine, as you can see, with the nice round stars that resulted in this image.
Canon 60D at the prime focus of the KPO 18″ Reflector. 30 subframes of 60 seconds each (due to the full moon) gives a 30 minute integrated exposure time. Captured and stacked in Nebulosity, processed in PhotoShop and finished in Aperture.
Click on the image for a larger version.