α Cam: Observatory

The Dahamm Observatory

My observatory is a movable mount carrying a C11 SCT. A Littrow spectrograph Lhires3 attached to the telescope with a strengthening aluminium profile. When in use the mount rests firmly on three paving stones.

my movable mount — The very sturdy mount was designed and assembled by a friend.

The polar alignment is made with the Pol-Drift Align feature in phd2. A qhy-5-ii with a 75mm lens is mounted on the prism rail just below the front of the C11. With a coarse visual orientation of the mount to Polaris the Pol-Drift Align feature is a quick and easy method to suffinciently align the polar axis of the mount.

The LH3 is equipped with a 35 µm wide slit, this is 2.6 arc seconds in the sky. A grating of 2400 lines per mm gives the resolution of around 12,000 at H_α.

A hole in the mount of the spectrograph gives access to the light path in front of the slit of the LH3. Here a ThAr holow cathode lamp is inserted to give wave length calibration all over the visual spectrum. On the right you see a Raspberry Pi piggypack mounted an the LH3 with some hook-and-loop strips.

This Raspberry Pi does the whole work. Collecting spectra and guiding the telescope i.e. hold the object star on the slit. The science camera is a Atik460EX operated with the indi software. An old QHY5 is connected to phd2. All software is remotely controlled via xpra from two elderly laptops running current ubuntu releases.