Friday, August 16, 2013


     On Wednesday August 14 amateur Japanese astronomer Koichi Itagaki discovered a nova in the constellation Delphinus.  He noticed a star in a photograph that wasn't in a similar photograph he took two nights earlier.  This was not a supernova which is the cataclysmic destruction of a star 8-15x more massive than the Sun.  A supernova is preceded by the collapse of the star under its own weight because it has spent too much of its fuel and gravity overcomes the outward pressure generated by the fusion process that stars use to burn. The last supernova in our galaxy that was visible to the naked eye from Earth occurred in 1604.  A supernova can briefly outshine the cumulative brightness of all the other stars in its own galaxy as it becomes 100 billion times brighter than the original star was during its lifetime.  When the red giant star Betelgeuse, in the constellation Orion,  goes supernova it will shine in our sky as bright as our sun does.
    Nova Delphinus 2013 was just an ordinary nova that occurs when the gravitational pull of a white dwarf star in a binary star system steals mass from its companion.  The extra mass causes a runaway nuclear fusion reaction and results in a rapid increase in luminosity of the white dwarf star.  The degree of brightness increase is on order of 10,000-1,000,000 times.
   Tonight I was able to photograph the nova from my yard.  It is the brightest star near the center of the photo below.  It is shining at about 5th magnitude,  which is dimmer than dimmest stars that I can see from my suburban yard. 

    Although the star appears no different than the surrounding stars, I was able to identify it by comparing it to a star map downloaded from Sky and Telescopes website.  Link.....Sky and Telescope Nova Press Release    In the photo below I highlighted the star groupings that I compared to the downloaded map, in order to find the nova.  My photo shows stars dimmer than the star map does.

added black lines to show star groups highlighted in my photo

The graph below indicates that the nova is already starting to fade.


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