Image Credit
& Copyright: Mike
Selby and Roberto
Colombari
NGC 3199 lies about 12,000
light-years away, a glowing cosmic cloud in the nautical southern
constellation of
Carina. The nebula is about 75
light-years across in this narrowband,
false-color view. Though the
deep image reveals a more or less complete bubble shape, it does look very
lopsided with a much brighter edge along the top. Near the center is a Wolf-Rayet star,
a massive, hot, short-lived star that generates an intense stellar wind. In
fact, Wolf-Rayet stars are known to create nebulae with interesting
shapes as their powerful
winds sweep up surrounding interstellar
material. In this case, the bright
edge was thought to indicate a bow shock produced as the star plowed through a
uniform medium, like a boat through water. But measurements have
shown the star is not really moving directly toward the bright edge. So a more
likely explanation is that the material surrounding the star is not uniform,
but clumped and denser near the bright edge of windblown NGC 3199.