The Royal Holloway University of London (RHUL) is located in Egham, Surrey, about 30km west of central London. It is a prestigious research-intensive university with a rich history and a stunning campus with a strong research profile, and diverse student community of nearly 13,000 students across arts, humanities and sciences including physics and astronomy. Baader Planetarium were honoured to be chosen to supply and install a substantial upgrade to their existing telescope which resides in a metal 3.8m diameter observatory slit-type dome on the roof of their physics department’s Tolansky building.
Discussions about a telescope and accessories that would be suitable for astronomical teaching and research projects began shortly after the beginning of 2025. After a number of meetings with departmental staff the following setup was chosen:
- Telescope System:
- PlaneWave CDK17 and L-500 Direct Drive Mount mounted atop an Equatorial Wedge.
- Series 5 controller for operating the focuser, telescope fans and internal heater pads
- Series 5 focuser
- The whole telescope would be fixed on top of a Baader Heavy Pillar (BHP) Levelling flange for Planewave L-Mount 500/600, Height 10cm (#2451188 , € 535,- ) which would be attached to the top of the observatory's existing concrete pier using a Baader levelling flange base.
- An imaging system for photometry, astrometry and astrophotography :
- Moravian C3-61000 PRO CMOS Camera EC with Sensor Sony IMX455 Full-Frame (36x24mm) (#1941100 , € 7610,- ) with a Moravian External Filter Wheel with 7 positions for C1x-/ C3 Cameras (50x50mm) (#1942101 , € 719,- )
- UBVRI Bessel Filter Set 50x50mm – photometric (#2961755 , € 1225,- ) .
- For spectroscopy projects :
- DADOS Slit – Spectrograph (#2458550 , € 2360,- )
- DADOS: Baader Blaze Reflection Gratings 200 L/mm (#2458557 , € 232,- ) , DADOS: Baader Blaze Reflection Gratings 900 L/mm (#2458556 , € 253,- ) , DADOS: Baader Blaze Reflection Gratings 1200 L/mm (#2458559 , € 323,- ) for different resolutions
- The DADOS was also equipped with a Spectroscopy Barlow (#2458645 , € 370,- ) to bring the telescope to f/10 for best use with DADOS
- To image spectra a Moravian C2-7000A Mono CMOS Camera with APS-C sensor Sony IMX428 (14,4x9,9mm) (#1941500 , € 1750,- ) is attached and a Moravian C0 mono USB camera for slit viewing and guiding.
- Visual use for occasional public and outreach events :
- appropriate M68 ClickLock adaptors and 2" ClickLock® clamp to M68a – for Zeiss-Norm / M68-System (#2956268 , € 92,- )
- Morpheus® 76° Eyepiece Set (complete) (#2954200 , € 1630,- ) .
In order to avoid having to keep removing and re-mounting the imaging, spectroscopic and visual equipment, the IMP85 – Instrument Multi Port (#2451300 , € 7950,- ) was also added to their equipment list. The telescope with all the equipment was set up, balanced, adjusted and tested at our facility in Mammendorf in the summer ready to be shipped and installed later in the year.
The telescope was delivered at RHUL in early October and the installation took place just after delivery over two days and just in time for an important University-wide open day event for prospective students.
The first day involved unpacking the equipment, sorting and preparing it all ready for installation the following day. The accessories were taken to a teaching laboratory where all the necessary and most up-to-date software and drivers were installed and configured on the observatory PC and tested and the photometric filters were installed in the filter wheel. Time was also spent demonstrating the operation of various software applications to some of the staff.
The next task centered around the observatory's existing short concrete pier onto which the whole CDK400 would be mounted. Measurements of this pier made earlier in the year showed that it would be suitable to allow the Baader pier adaptor to be attached with the wedge and support the telescope. It was also found that its height was also suitable to allow the telescope to reach the minimum required altitude. The pier was then drilled and chemical anchors put in place with the Baader flange adaptor then put in position.
The last job of the day was to partly dismantle the wedge and carry it up the (very) narrow spiral staircase that leads into the observatory so it was there ready to be fitted the following day.
It was not possible to use a crane at the time of the installation so an external “transport team” who have previous experience of moving delicate heavy equipment for the department were chosen to carefully move the L-mount and telescope to the roof and into the observatory. The mount and telescope had to be moved from the ground to first floor, then into a narrow room, up a steep and narrow staircase and up through a small access door and onto the roof before being finally installed in the observatory. Measurements of the mount and telescope has been given earlier and it was found that although space was tight, both of the large heavy items should just about fit and be able to be moved onto the roof and into the observatory.
The telescope installation day started early with the arrival of the team setting up a portable gantry lifting system on the roof which would take the weight of the heavy mount and telescope (separately) and enable the items to be raised onto the roof. After discussing how to move and safely lift each item, the L-500 and CDK17 were removed from their crates on the ground floor and the journey to the roof top observatory began. The L-mount was the first to go up and after wrapping it to protect it from damage it was safely hoisted up onto the roof. The CDK17 was next where it also was safely moved onto the rooftop. After less than an hour both the mount and telescope were ready to go into the observatory.
Inside the dome, the Baader levelling flange was put in place and levelled with the wedge being attached next. The transport crew helped with lifting the L-500 onto the wedge where it was then secured. After a well deserved coffee the CDK17 OTA was then clamped onto the L-500 mount ready for the accessories to be attached.
The IMP85 was fitted to the OTA followed by the imaging system, DADOS spectroscopy accessories and then the visual items. The department’s small APO refractor telescope with imaging camera was then mounted on top of the CDK17 and positioned so the telescope was perfectly balanced in DEC. Temporary cable routing was done as the department was going to purchase an industrial mini PC a short time afterwards which would be mounted on the L-mount and also use much shorter length data cables from the various accessories.
The day ended by testing the equipment operation and tuning the mount. Time as also taken to explain further operation of the equipment such as camera operation and how to undertake the mount modelling and polar alignment.
It was great to do this telescope installation in such a nice and friendly campus environment and the whole process went very smoothly. The departmental technicians Ian Murray and Adriana Dias were great to work with and their help and support was greatly appreciated. The "moving crew" were also great to work with and very helpful. Thank you to Adriana too for the use of the timelapse and drone videos too.
Update 19/11/2025: The department obtained an industrial mini PC and shorter length data cables allowing the computer to mounted on the side of the DEC arm with modified cable routing. They have also had a recent clear night which allowed them to undertake mount modelling and get towards a good polar alignment.
