In my recent photograph of the Great Nebula in Carina with 3nm Halpha filter, I have noticed an unusual looking star. After plate-solving with Aladin software it has been identified as a double object. I looked this star up on various photographs, but it always looks ‘normal’, except for my image.
The first image indicates location of this star within the nebula (right next to the cross).
The second image shows the star; left side is without any processing, right side has been processed to enhance the irregularity.
The third image is a screen shot from Aladin.
Full resolution image: http://www.astrobin.com/148715/C/
Would anyone be willing to able to help identify the cause for this irregularity?
