Observatory Equipment

Location

Lat: S 35º 09' 44.700" + 2.359m
Lon: E149º 06' 36.030" + 1.365m
Elevation: 660.26m + 2.851m
(Result of 3000 averaged measurements via GPS)

Telescope

Meade 14" LX200GPS (0.35m)

The telescope is mounted on a Mitty Evolution 14 wedge (see below) which in turn is mounted on the supplied Giant Field Tripod.  I had considered a pier, but the Giant Field Tripod is very big, very heavy and very stable.  Each tripod foot is seated on it's own concrete pier dug 18" into the ground and isolated from the observatory floor.  The setup is so stable that I have not had to adjust polar alignment in over 8 years.

This telescope has f/10 optics and a 2" SCT back.  It is fitted with the standard Meade Zero Image Shift microfocuser which has been able to support the weight of focal reduced, filter wheels and SBIG Cameras.

Guide Scope

Meade 4" 1020 Telephoto Lens (0.102m)

This is a vintage 'scope' circa 1982/83 was made in Japan.  I found it in a Ted's camera store in their second hand window and bought it immediately when I saw it had a standard Meade SCT back.  This lens has done an excellent job over the years as my guide scope.  It has a very smooth helical focuser and I have fitted it with a Meade f/6.3 Reducer to increase it's FOV for the relatively small chip on the Starlight Xpress MX716 ccd that I use as a guider.

Spectrograph

Littrow Design Spectra L-200 Spectgrograph

This is a medium resolution f/200 spectrograph supplied with a 600 l/mm grating.  The design has been tested with 1200 l/mm gratings so it can reach the low end of high resolution.  The Spectrograph as supplied in Kit form by Ken Harrison but has suffered a couple of flaws - mainly the T threads for the Camera and Telescope mounting plates.  They weren't cut large enough and so do not support the multitude of T Thread adapters out there.  Ken is working hard to solve this problem.

See details of the construction and calibration of the L200 here.

Losmandy Guide Scope Mount

Losmandy Guide Scope Mount

Prior to installing this mount I just used a couple of lengths of aluminium angle bolted together and screwed to the 2 scopes.  It proved stiff enough for all my work over a period of 8 years but with the purchase of the spectrograph, I needed to use the guide scope as the pointing and alignment mechanism so I needed something that would allow me to easily adjust the guide scope to the FOV of the main scope.  The Losmandy accessories are very well engineered but also very heavy and I had to add an additional 5kg of weight to re-balance the scope.

Wedge

Mitty Evolution 14 wedge

In order to do any imaging, the fork mounted SCT needs to be 'equatorially' mounted.  This means a wedge of some sort.  The Meade 14" is a large and heavy telescope and standard Meade Wedges are not up to the task.  I came across the handmade Mitty Wedges whist waiting for my Meade scope to arrive from the states.  It is a very well engineered wedge with all the appropriate adjustments and turned out to be very easy and smooth to setup.

Cameras

I started with a Meade LPI back in 2001 when I had the 8" LX90 (and I still have the LPI though I don't use it anymore)  I quickly moved to a 'proper' camera an purchased a Starlight Xpress MX516.  The FOV was tiny and not very productive so I upgraded to an MX716 (ST-7 sized).  An SBIG ST-8 'dropped' into my lap in 2005 when I won my first Gene Shoemaker NEO grant, and this became the observatories mainstay for many years.  Over the ensuing years I bought and sold a second MX716 and an SBIG ST-9.

In 2011, with the money from another Gene Shoemaker Grant, I purchased an SBIG STL1001e.  Now I am after another small, sensitive CCD with small pixels to use with the Spectrograph, most likely an Atik 314L+.  It seems to be most suited to the specifics of the L200 and considerably smaller (in physical size and more importantly weight) to the ST-8.

SBIG STL1001E with integrated Filterwheel

A large format, professional grade CCD camera from SBIG.  The STL1001e has a 1024x1024, 24micron CCD chip with a peak QE of a little over 70%.  This configuration allows me to operate the camera at near f/10 on the 14" SCT (with the Meade Microfocuser attached the result is actually f/9.4) resulting in a 25.4 arcmin square field at 1.48 arcsec/pixel resolution.  First light for this camera was 23 April 2011. Although the Camera has an integrated filter wheel, 2" UBVRI filters are very expensive so none are fitted as yet.  However, par focal Custom Scientific V, R and C filters are on order.  Mind you there appears to be a serious construction flaw in this camera given the filterwheel circuit board joint 'popped' off the circuit board when the camera face plate was removed.  This isn't an isolated incident either (I know one owner who has had this happen 3 times and a lot of other users came out of the woodwork when I posted the issue on the SBIG user forum) but SBIG quickly came to the party and is sending a replacement part.  I did some testing on the old part and the design is sound, as long as the solder joints are robust so the issue seems to be with the quality of construction rather than the design.

SBIG ST-8E with CFW8 Filterwheel

Although a Parallel interface camera, the ST-8E has been the mainstay of the HHO for more than 5 years.  To cater for automation, the camera and CFW8 filter wheel were fitted with a Meade F/3.3 Focal Reducer resulting in an f/4 imaging system.  The resulting field curvature was a drawback but since it is a parallel camera, full frame image downloads took too long (59 seconds) so sub frame imaging was introduced to combat the vignetting and the download times.  As a result, reasonable images were obtained with only an average 20 second delay at 1148 x 768 px.  The only other issue was that during image download, the camera took over all the computers CPU cycles and as a result accuracy of system time was grossly affected (I found instances where the system clock was off by 200+ seconds at the end of a nights run - even with internet time synching operating.  This, and the relatively slow image download times made the camera useless for NEOCP followup work.

Imaging System & Control

Connecting it all up

My aim has always been - "Plug and Play".  So when I put the observatory together I wanted to keep it all simple so this is how it all goes together:

All the hardware and software is off the shelf, commercially available software. In some instances Serial to USB converters are required and used to support some of the older hardware (like connection from Computer to the LX200GPS base and connection from the computer to the Star2000 guider control box).  The Star2000 just connects from the LX200 port to the LX200GPS Autoguider port.  The Computer connection just plugs into the primary RS-232 port on the LX200GPS.  The cameras are connected to the Computer via the Parallel port (SBIG) and USB port (SX).  That's it - plain and simple.  BUT, take care.  Those long cable runs between the computer, power, telescope, cameras etc can easily snag and tie your system into knots.  Make VERY sure that you have them all policed and positioned such that it is impossible for anything to snag else you risk burning out you telescoped drive(s)/electronics or in a worst case, toppling your telescope.  For months I ran an IR webcam inside the observatory linked to a monitor in the house so I could keep the scope under surveillance until I was sure the scope would not run into any problems.

Computer et al

Literally anything will do as long as it has the connections to support your software and hardware.  Remember, some modern cameras have very large images so your hardware may need a lot of RAM to cater with large format images.  If you want to observe remotely then you can use WiFi if the distance between the Observatory and house is not great but for reliability, you may wish to lay LAN cable.  LAN cable is cheap so the biggest expense is just digging that 18" deep trench.  Reliable power is also important.  Batteries are OK but can run down and are affected by cold.  I run 240vac from the house to the observatory in the same channel I dug for the 2 LAN cables, 2 phone lines and an RCA line (RGB + Audio).  So my observatory runs a 12v, 15amp power supply that feeds the scope and dew heaters.  The cameras have their own supplies as does the computer and monitor.  I also have a combination of AC and battery (solar charged) lighting.

For time based imaging, a reliable (and fast - for low latency) internet connection is also preferable.  To cater for my version of ACP (Single Internet user) I also have a static IP on my internet line so that I can connect to the observatory from anywhere I can get an internet connection (including my iPad from anywhere it can get a WiFi or 3G phone connection)