Image data acquisition remotely byImmo Gerber and Dietmar Hager at Tao.

Image processing by Dietmar Hager: CCD Stack, Maxim DL, Registax (Wavlelets), CCD Stack (Deconv.), CCD Sharp, PS CS3

9" TMB folded Apo @ TAO - ST 11k apprx. 70 h @ -20° cent. All frames 1x1 binned. Dark, Bias and (Sky)Flat corrected.

Seeing conditions during HA-data acquisition below average, transparency very good. Seeing conditions for R, G average. Seeing conditions for B and L fine. Transparency in RGB very good. Moon present while imaging L and B.

The Crescent Nebula, aka NGC 6888, is a very well renown and most intriguing object located in the constellation "swan" in the northern hemisphere. At an apparent size of about 18 by 13 arc-minutes it is a very pale nebula. Even in a moderate amateur telescope you cannot see this nebula. One would need absolute dark skies (or narrow band filters) and a decent "light buckett" to glimpse the nebula visually. It's absolute diameter is some 25 by 18 light years. Gazing at NGC 6888 means we are looking 4700 Years into the past.

NGC 6888 renders a nebula coming from the blueish star at the center. And this is known to once have been a super-giant star. That means the star has had a giant mass! Small stars like our sun dwell some Billions of years with their fule. Super Giant stars are kind of play-boys, as they deplete their fule at "full speed". And in this particular case the central star qualifies for being summed upon the socalled "Wolf Rayet" stars. After only a coule of Million years the fule is almost used up and the star is standing right before a significant change: it is gonna go supernova quite soon,...spoken in cosmmological terms, though. So, at present we are looking at a star that vents its outer layers into space at terrific speed and therefor the star sustains severe loss of mass. The gas is holding lots of oxygen and hydrogen,...just before the individual big "bang" of the WR-star.

Read an intruiging story about the Crescent-nebula written by Tammy Plottner from UT.