The Dahamm 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 ┬Ám 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 Hα.

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.

attached ThAr lamp

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.

attached ThAr lamp

Last modified: 2022 May 16