light-years, it is the closest known planetary nebula. determination method: SHA-1 described at URL: https://noirlab.edu/public/images/noao-02179 URL: https://noirlab...
light-years, it is the closest known planetary nebula. determination method: SHA-1 described at URL: https://noirlab.edu/public/images/noao-02179 URL: https://noirlab...