Explanation: 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.
(Text from apod.nasa.gov/apod/ap050728.html)
This photo was taken may 2011 in Khlepcha observatory near Kiev, Ukraine.
Equipment:
reflector S&K 200 mm. f/5, Mount WhiteSwan-180, camera QSI-583wsg,
Tevevue Paracorr. Off-axis guidecamera Orion SSAG.
LRGB filter set Baader Planetarium.
L: 15x600 sec., RGB: 5x600 sec. each filter, all unbinned.
North up.
Processed Pixinsight and Photoshop CS5.