NGC 5307: A Symmetric Planetary Nebula
Some stellar nebulae are strangely symmetric.
For example, every major blob of gas visible on the upper left of
NGC 5307 appears to have a counterpart on the lower right.
This picture taken by the
Hubble Space Telescope
was
released last week. NGC 5307 is an example of a
planetary nebula with a spiral shape.
Spiral planetary nebulae
are thought to be caused by a bright central
white dwarf star
expelling a symmetric
wobbling jet of rapidly moving gas.
It takes light about 10,000 years to reach us from NGC 5307, and about 6 months just to go from one side to the other.
In contrast, light takes only about 8 minutes to reach
Earth from the
Sun.