back M 27

Object: M 27 - Dumbbell Nebula
Imager: Dipl.-Ing. Johannes Huwe
Date & Location: 7. april 2003, NMSkies
Optics / Telescope: Celestron C14 SCT, SBIG ST1001E
Focal length f/ratio: 3910 mm @ f10 (no guiding)
Exposure: 20 min total, LRGB
L = 5 (1x5) min, binning 2x2
R = 5 (1x5) min, binning 2x2
G = 5 (1x5) min, binning 2x2
B = 5 (1x5) min, binning 2x2
Software: Camera control and image reduction with CCDSoft, RGB Combine in MaxIm DL, processed with Photoshop
Comments: Image Preview - Image prozessing not finished.
Conditions: Extrem windy (8-25 mph).
Object Info: The Dumbbell Nebula M27 is a planetary nebula. Estimated age of 3000 to 4000 years, i.e. the shell ejection probably would have been observable this time ago (it actually happened earlier as the light had to travel all the distance of perhaps about 1200 light years).

Adopting the distance of 1200 light years, the intrinsic luminosity of the gaseous nebula is about 100 times that of the Sun (about -0.5 Mag absolute) while the star is at about +6 (1/3 of the Sun) and the companion at +9..9.5 (nearly 100 times fainter than the Sun), all in the visual light part of the electromagnetic spectrum.
That the nebula is so much brighter than the star shows that the star emits primarily highly energetic radiation of the non-visible part of the electro-magnetic spectrum, which is absorbed by exciting the nebula's gas, and re-emitted by the nebula, at last to a good part in the visible light.

Apparent Dimension 8.0x5.7 arc min.