Explanation:
The lovely, symmetric planetary nebula
cataloged as MWP1 lies some
4,500 light-years away in the northern constellation
Cygnus the Swan.
One of the largest
planetary nebulae
known, it spans about 15
light-years.
Based on its expansion rate
the nebula has an age of 150 thousand years,
a cosmic blink of an eye
in the 10 billion year life of a sun-like star.
But planetary nebulae represent a very brief final phase in
stellar
evolution, as the nebula's central star shrugs off
its outer layers to become a hot white dwarf.
In fact, planetary nebulae ordinarily only last
for 10 to 20 thousand years.
As a result, truly
ancient MWP1
offers a beautiful
challenge to astronomers studying the evolution of its central star.
