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    Perspectives | American Journal of Neuroradiology  
    


















    


























    
  
  




    
    

  

      


    

      

  
  
  

    

  

    

  

                
    

      

  

    

  
      
  
  

    


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Perspectives
  
    	
Jeffrey S. Ross

  
    	
American Journal of Neuroradiology April 2023,  44 (4) 357; DOI: https://doi.org/10.3174/ajnr.P0133 

  
  
  



  


  
  



  
      
  
  

    
Figure
The Helix nebula (NGC 7293) is a poorly named “planetary nebula” located in the constellation of Aquarius, and sometimes referred to as the “Eye of Sauron.” Planetary nebulas have nothing to do with planets and were erroneously named because they seemed to resemble gas-giant planets with the equipment of the time (circa 1824). The dying of a star causes the ejection of its outer gaseous layers and leaves behind a white dwarf star (center of the eye). This image was acquired as a series of 96 5-minute exposures (8 hours) using red, green, and blue filters. The telescope was a 12.5” Ritchey-Chretien telescope, f/9 on a Paramount ME mount situated in Australia. The camera was an Apogee Alta U16 CCD with Astrodon filters. The images were processed using PixInsight, Photoshop, and Topaz Labs Adjust AI and DeNoise AI.
  


  
  



  



    

  



  

                
    

      

  

    

  
      
  
  

    


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