Astroimages by Friedhelm Hübner

50N8O?

50° North, 8 Hours East, these are approximately the coordinates on earth where I live and where I do astronomy as a pastime.

As a member of our local club, the Amateur Astronomers of the Rheingau (AAR), I have the privilege to use the club's observatory on the Rheinberger Hof, a farm near the little village of Presberg. Presberg is situated north of the Taunus-ridge on an elevated plain at an altitude of 380 meters, surrounded by the valleys of Groloch, Wisper and the Ernsbach. This "mesa" is the westernmost location usable for astronomy that can be reached from my home without crossing the Rhine. Driving distances increase seriously in order to get farther away from the Rhine-Main-area.

Conditions

The Rheingau is situated on the western edge of the greater Rhine-Main-area, an agglomeration of 2,500 km² with about 2.2 million inhabitants, numerous towns and cities, the Frankfurt airport and industrial areas with the corresponding light pollution.
Air pollution improved considerably since the 1970s, so transparency often is quite good despite the high humidity caused by the river Rhine, but light pollution and the growth of the light pollution domes increased massively. Contrails are more and more responsible for thin cloud-decks during phases of fair weather.
In spite of the proximity to the greater Rhine-Main-area at the site of the AAR-observatory in an average night the milkyway is clearly visible, in the zenith finely structured; M31 almost always can be seen with the naked eye. But in the east fainter objects below 50° elevation disappear in the glow, in the south it is the same below 30° elevation. So the summer milkyway-objects in Sagittarius or Scorpion are seldom seen to advantage.
In an average night I would rate our skies according to the Bortle Dark-Sky Scale a 4 (Rural/suburban transition), in a rare good night it gets a 3 (Rural sky).

Astrophotography

After I realized that my favourite deep sky-objects could be extracted again from the orange-grey murk with the help of digital cameras and image-processing tools, I changed from solely visual observing to photography.
I started with a DSLR, a Canon EOS 300D attached to 4- and 6-inch-optics, and a long and still ongoing fight with and against complex equipment started. For a long time the goal was only getting an ever growing complex system to work as it should do in my opinion. Sometimes I succeeded, there are images.
Since the summer of 2008 I use a SBIG ST10XME CCD-camera and try to keep up with the challenge again. It's still far from perfection, but it keeps getting better.

In March 2009 the first long exposures with a 13-inch Newton were produced, in December 2009 a 26-centimeter Newton was put into service, and the last acquisition in November 2010 was a 10"-Ritchey-Chrètien.