M 27 - first light image for 4" air-spaced APM-Apo
L(L-HA)-R(R-Ha)-G(G-O3)-B
this image renders a shake-down for a new brand of apo: APM air-spaced triple apo with TS-focuser TSFOCR3
the focuser provided in the test-kit is very reliable for visual use and probably stable enough for a light camera (OSC from SX e.g.), but obviously it was overloaded with the weight of flattener, FLI and CCD-camera, as you can probably tell by looking at the full size image: the image train was slightly tilt, therefor the stars to the left are sharp, to the right they are not...(no deconvolution was applied to the starfiled - only the nebula). nevertheless, the performance of the lenses is quite promising. further tests are scheduled once a more stable focuser is provided by the company. Being discovered by Charles Messier in 1764, M27, aka "the dumbbell nebula" is a well renown planetary nebula (PN). It is located in the constellation "vulpecula" somewhat close to the "summer triangle". M27 is one of the largest PNs in the northern hemisphere holding about 6.7 arcminutes in diameter (it appears about 6 times larger than jupiter) and M27 is quite luminous as it shines at 7m6 (blue), so you can find it easily in a regular bino. Its abolsute diameter is about 2.5 light years (the brightest parts). Change for the image I acquired with my 9" scope (link provided above), you can see the outer shell structure which make the PN even larger (15 arc minutes - resulting in some 5.5 to 6 light years; about 6 times the diameter of the Oort-cloud to give a comparision to our solar-system). According to Chudowitchera some of the brighter parts of that nebula expand at a relative velocity of 6 arc seconds per century, allowing estimations of age: some 3-4000 years. Though M27 is some 1200 Light years away from earth even the faint outer shells can be observed in a large amateur telescope, utilizing narrow band filters. particularly the greenish structures, which render huge masses of oxygen, are easily visible, as the human eye's sensitivity peaks in green. |