NGC 6302 (also called the Butterfly Nebula,
or Caldwell 69) is a bipolar planetary nebula in the
constellation Scorpius. The structure in the nebula is among the
most complex ever observed in planetary nebulae. The spectrum of
NGC 6302 shows that its central star is one of the hottest stars
in the galaxy, with a surface temperature in excess of 200,000
K, implying that the star from which it formed must have been
very large. The central star, a white dwarf, was recently
discovered using the upgraded Wide Field Camera 3 on board the
Hubble Space Telescope. The star has a current mass of around
0.64 solar masses.
