Sunday, February 26, 2012

Owl nebula

       Just another name for the spooky object staring at us from the Ursa Major, Owl Nebula is a glimpse in the future. The... far future. Billions of years from now, our Sun will get much larger, entering the asymptotic giant branch stage, where stars oscillate and eject a lot of their mass through stellar winds, somewhat like the much more massive Wolf-Rayet stars. It all ends with a lot of gas surrounding a small white dwarf star, which is hot enough to excite it in to the glowing business (tens of thousands of degrees Kelvin). 

     It might be a bit sad, as this is the peaceful death of a star (unlike supernovae, which usually help giant molecular clouds collapse and form more stars), silently contributing to the chemical enrichment of our own Milky Way and other galaxies. And it all ends in ~ 10 000 years, a rather short moment compared to the lifetime of the progenitor stars. 

      2600 light years away (or about 24597373900000000 kilometers :P), 3 light years across (so it's 3.3 arcminutes wide as seen from Earth), quite low surface brightness. And it's watching you.

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