NGC 2438
NGC 2438 is a planetary nebula about 3,000 light years away in the constellation Puppis. It was discovered by William Herschel on March 19, 1786.
NGC 2438 appears to lie within the cluster M46, but it is most likely unrelated since it does not share the cluster's radial velocity. The case is yet another example of a superposed pair, joining the famed case of NGC 2818.
Long exposures have shown that this planetary nebula has an extended double halo, while the more easily visible portion probably dates to the death of the red giant in its center.Central star
The central star of this planetary nebula is a 17.7-magnitude white dwarf, with surface temperature of about. It is one of the hottest stars known.Gallery
