Owner: Linden Observatory, NSW
Known as: The Evans Telescope
Upgrades: fitted a new powered ground board, full ServoCAT goto with Argo Navis and 10K encoders plus a new 27point stainless steel mirror cell with cable sling and a Feathertouch FTF2525 focuser with a 2.5″ diameter drawtube which is big enough to insert a video camera into the barrel.
On Sunday evening 8pm several WSAAG members attended Linden dark sky site for an unscheduled star test of the Evans 30 telescope. This was its first starlight since its refurbishment by Peter Read of SDM telescopes. The weather was initially dubious on the Sydney plains, but the higher altitude of Linden allowed for a slight breeze and fair seeing which improved with the evening.
Present were Rob Horvat, Gerry Flanagan, Lachlan Davis, Tony Barry, and Alan Plummer. The first task was to get used to the setup and alignment of the Argo Navis system, and the method for Goto with the StellarCAT drive. This task is straightforward, but as with everything the details do matter, and we repeated the process until confident that it could be done again in the dark.
Rob was eventually able to control the telescope remotely, with his iPad, allowing rapid and accurate slews to any part of the sky visible at the time. Gerry confirmed the settings for his iPad, and the consensus was that the iPad remote system was a significant upgrade to the ease of use and utility of the scope.
The temperature hovered around 8 degrees for the duration of the star tests, and the mirror cell, once collimated, remained in excellent alignment for the night. The new mirror cell has improved this behaviour considerably.
The list of objects that were targets was frankly astounding. It became possible to decide on a target, slew, and visualise within sixty seconds …
and this permitted the members to view M27 (the Dumbbell Nebula), M57 (the Ring Nebula), NGC 7009 (the Saturn Nebula), M17 (the Swan Nebula), NGC6514 (the Trifid Nebula), M8 (the Lagoon Nebula), eta Carinae, the globular clusters 47 Tuc and omega Centauri, Centaurus A (NGC 5128), Neptune and its 14th magnitude moon, Triton, which was a first for most of the members, Saturn and five moons, with the Cassini division being clearly visible, Albireo (the double star with one blue and one orange component), the Grus Quartet of galaxies (NGC 7552 / 7582 / 7590 / 7599), the carbon star V Aquilae, NGC 4755 (the Jewel Box), M83 (the Southern Pinwheel Galaxy) , M104 (the Sombrero galaxy), NGC 6705 (the Wild Duck Cluster), and NGC 4038 (the Antennae Galaxies).
Of these, M17 (the Swan Nebula) was especially striking, with the hairlike strands of nebulosity in the main portion being quite patently visible. The dark lane in NGC 5128 (Centaurus A) was confidently split by a thin strip of brightness which was scarcely visible in the video camera on the LX90, but easily seen with the eye on the Evans 30. Triton, the moon of Neptune, was an unexpected find, visible in the 8mm Ethos eyepiece at a breathtaking 14th magnitude. The central dark lanes in NGC6514 (the Trifid Nebula) were very well defined. Some objects were viewed several times in the night, such as NGC 7009 (the Saturn Nebula).
The video camera insert distance was measured and noted – this will require a new machined adapter to allow the Point Grey camera to fit into the draw tube some distance, but once this is done the telescope will be a formidable tool for occultations.
The test concluded at 2:50am, with cloud beginning to cover the sky to the east and a gentle breeze blowing from the west. Temperature was 7 degrees as the members left the site.
Regards, Tony Barry (WSAAG)