Dumbbell Nebula (M 27)

clic for 32% size 1200 x 860 (440 kB)

clic here for 50% size 1773 x 1271 (660 kB)

 

About this Image

The Dumbbell Nebula M27 was the first planetary nebula ever discovered, back in the year 1764 by Charles Messier. This planetary nebula is certainly the most impressive object of its kind in the sky, as the angular diameter of the luminous body is nearly 6 arc minutes.
The central star of M27 is quite bright at mag 13.5, and an extremely hot blueish subdwarf dwarf at about 85,000 K. A faint outer shell spans to 15 arc minutes across, mainly visible at H-alpha and O-III wavelengths. The nebula is apparently expanding at a rate of 6.8 arc seconds per century leading to a calculated age of approx. 4000 years.

By comparing images of the Dumbbell Nebula M27, Leos Ondra has discovered a variable star situated apparently in the very noth-western outskirts of the nebula which he called Goldilocks' Variable. The period of this variable star is estimated at 213 days.
The distance to this nebula is approx. 1250 light years.
North is up.

More information:
Global Kinematics of M 27: 1.
Goldilocks variable: 2.

Below you see a crop on the center of the above image in 32/80% size.

clic for 80% size 1520x1430 (580 kB)

 


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 Ha, LRGB
Date July 16 - 17, 2006.
Location Wildon/Austria
Sky Conditions mag 5 sky, raw FWHM 1,8"
Exposure Ha = 120 minutes (30 minute sub-exposures),
L:R:G:B = 60:30:30:30 min (10 minute subs)
Processing Image aquisition in Maxim 4.11; Calibration and color combine in CCDstack;
H-alpha incorporated into red channel; final processing in Photoshop CS2;