Ring Nebula (M 57)

clic for 50% size 1554 x 1160 (175 kB)

 

About this Image

The very well known Ring Nebula (M 57) is a showpiece of a planetary nebula, situated in the constellation of Lyra.
The bright shell (60" x 80"),radiates from UV in the center to the greenish Oxygen and Nitrogen and finally red H-alpha light in the oval shell. It is enveloped by a larger very faint mainly red halo from its earlier stellar winds, extending up to 300".
The mass of the nebula has been estimated to amount 0.15 solar masses, while the 16 mag central star is believed to be of about 0.7 solar masses. Its dynamical age calculated from its expansion rate is about 7,000 years. The distance to this nebula is approx 2,300 light years. To the north-west of M 57 there is the mag 14.3 background galaxy IC 1296. North is left.

Below you see a crop on the center of the above image in 120% size.

Even below you see a first trial on the faint outer shell with 1 hour of additional H-alpha exposure in 60% size.

 


Technical Details
Optics

16" cassegrain in secondary focus at f/10

Mount MK-100 GEM
Camera SBIG STL-11000M at -15C, internal filter wheel
Filters Astronomik LRGB
Date May 02, 2005.
Location Wildon/Austria
Sky Conditions mag 5.5 sky, raw FWHM 2", temperature 15 C
Exposure L:R:G:B = 5:15:15:15 minutes (5-minute sub-exposures), 2x30 minutes for H-alpha
Processing Image aquisition, calibration and LR deconvolution in Maxim; color balance, curves, unsharp mask in Photoshop; Noise reduction by Neatimage;