[Bluearrowll]

What's in the sky tonight?
October 8, 2012

-Even as the stars begin to come out in twilight, Cassiopeia is already higher in the northeast now than the sinking Big Dipper is in the northwest. Cassiopeia's broad W pattern is standing on end.

-Mars (magnitude +1.2, in Libra) remains low in the southwest in evening twilight. Don't confuse it with twinklier orange Antares ("Anti-Mars") to its left. The gap between them shrinks from 11° to 7° this week. They're nearly the same brightness.

Astro Picture of the Day:
October 8, 2012

Source:
Ghostly in appearance, Abell 39 is a remarkably simple, spherical nebula about five light-years across. Well within our own Milky Way galaxy, the cosmic sphere is roughly 7,000 light-years distant toward the constellation Hercules. Abell 39 is a planetary nebula, formed as a once sun-like star's outer atmosphere was expelled over a period of thousands of years. Still visible, the nebula's central star is evolving into a hot white dwarf. Although faint, the nebula's simple geometry has proven to be a boon to astronomers exploring the chemical abundances and life cycles of stars. In this deep image recorded under dark night skies, very distant background galaxies can be found - some visible right through the nebula itself.