Big Dumb

Abell 39, about 7000 light years away, is a ghostly remnant of a Sun-like star and one of the largest existing spheres in the Milky Way. Six light-years across, it was once a sun-like star’s outer atmosphere expelled thousands of years ago. The nearly perfect spherical nature of Abell 39 allows astronomers to accurately estimate how much relative material is actually absorbing and emitting light. Observations indicate that Abell 39 contains only about half of the oxygen found in the Sun, an intriguing but not surprising confirmation of the chemical differences between stars. The central star is also offset from the center of the 2.5 light year diameter bubble by about 0.1 light year  - somehow the cloud that was ejected is thought to have been asymmetric, but for unknown reasons. Several galaxies millions of light years away can be seen through and around the spectral nebula.

Gate of the Hroraq