Last updated 14 Sep 2017

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Equipment Upgrade June 2005

The Meade 12" (0.3-m) LX200GPS Schmidt-Cassegrain telescope installed in May 2002 was replaced with a Meade 16" (0.4-m) LX200GPS SMT Schmidt-Cassegrain telescope during June 2005.

The 12" telescope was dismantled on 5th June 2005 (but see below for an update) as a replacement pier and equatorial wedge was delivered, ready for the expected delivery of the 16" in the coming week.

The top of the original 1-m high old pier and the old wedge can be seen here in a photograph of the 12" telescope from Oct 2002:

The new 16" telescope is of more massive construction and the forks holding the optical tube assembly are longer, dictating that the original 1-m high pier needed to be replaced with a shorter pier, to reduce the overall height of the 16" telescope to match the height of the 12" telescope.

The original position of the 1-m high 12" pier can be seen as the circular ring in the centre of the floor (with the pier itself moved to the far wall of the observatory). The new 0.6-m high pier is shown to the left (south) in approximately the position required for the 16" telescope to be positioned in the centre of the observatory dome, with the overhang to the north of 0.75-m taken into account (though this was subsequently revised to 0.55-m overhang).

Here the old pier and wedge (left) has been placed alongside the new shorter pier and wedge (right) to show the difference in size of the two assemblies:

Originally due at the end of May 2005, delivery of the new 16" telescope was delayed by the shipping company and on 7th June 2005 the expected delivery date was put back to the week commencing 20 June 2005, so in the interim the 12" telescope, pier, wedge and electrics were re-commissioned over 7th and 8th June, allowing further astrometry to be obtained from 8 June 2005 until the night of 22/23rd June 2005. During 23rd June 2005 the 12" was finally decommissioned.

Update 26th June 2005

The 16" telescope was finally delivered on Thursday 23rd June 2005 and with the help of Peter Gallon from Telescope House who supplied the new telescope, the 12" and its pier were removed, the new pier was secured to the observatory floor and the new fork assembly attached to the new wedge.

The lower part of the forks is shown above, the top part being integral with the optical tube assembly (OTA) which was added later (see below).


Peter Gallon (right) and Peter Birtwhistle after lifting the OTA onto the forks.

Below, the 16" is shown, having been connected to power, the CCD and pc and is ready for polar alignment and other adjustments, such as Periodic Error Correction (PEC) in the RA axis (which compensates for any slight mechanical imperfections in the worm gear) and training the Meade Smart Mount (which allows for better pointing accuracy by removing any systematic pointing errors).

Final commissioning of the 16" to accurately align the polar axis using stars was done using PoleAlignMax and by training the internal RA drive Periodic Error Correction setting.

First light was achieved on 27 June 2005 with an image of M51 and unknowingly picked up a pre-discovery image of a Type-II supernova 2005cs on the rise!


 

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