This is the first image of an astronomical object I ever took with my ST-7XE camera. Last night, I mounted the telescope in ALT-AZ mode, attached the camera, pointed the telescope to Polaris, roughly focused it, and shot this 10 second exposed image. The camera was cooled to -10°C.
As this was just a simple camera check, even the telescope tracking was completely turned off.
Polaris itself is completely overexposed in this image, and the raw image contains blooming streaks above and below the star, proving that this camera indeed has a NABG sensor. You see, Astronomics initially sent me an ABG version, which I returned immediately after discovering this using a pin-hole test.
I manually cleaned the blooming streaks (some artifacts are still visible), and used non-linear histogram stretching to improve the visibility of the companion.
Polaris is a binary star at a distance of 431 light years, consisting of a bright magnitude 2 supergiant and a much dimmer magnitude 9 main sequence star, separated by about 18 arcsecs. Even though this 7 magnitude difference makes it a bit harder, I found on 2005-03-25 that I could easily resolve the binary with my 80mm refractor at a magnification of 31x.
From the original (bloomed) image, I determined that the apparent distance between the two components is 26.7 pixels. Attaching the camera directly to the focuser therefore results in a system with a focal ratio close to f/11.
The same night, I also took my first image of galaxy M82.
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