The NMSU 1m is an F/6 alt-az Ritchey-Chretien telescope located at the Apache Point Observatory. It was constructed by the AutoScope corporation, although the company went out of business before they really completed the project.

The 1m dome is the small dome located closest to the 3.5m dome. We currently have a rotating tertiary with instruments at the two Nasmyth ports: NA1 has a 2048x2048 LN2 cooled CCD camera on a instrument derotator, while NA2 has a single-object multi-color photometer that uses a combination of PMTs and APDs as detectors, along with a aperture-viewing camera; the photometer is not on a rotator.

The 1m is normally run in robotic or remote mode. This manual describes the interactive command set used for interactive observing, and provides some notes on scripts used for robotic observing.


As of 2008, there is a rotating tertiary that can be directed on either of the Nasmyth ports.


There is an imaging camera on an instrument derotator at the NA1 port. This camera uses a E2V 2048x2048 CCD that is cooled in a LN2 dewar. The electronics were supplied by Bob Leach of Astronomical Research Cameras. The pixels are 13.5 microns on a side, giving a pixel scale of approximately 0.46 arcsec/pixel.

The camera is mounted behind a guider box and filter wheel. The filter wheel holds 10 2x2 inch filters; UBVRI, ugriz, Washington CM, DDO51, and some narrow band filters belonging to Rene Walterbos are available.

The guide box has a Finger Lakes Instrumentation CM2-1 camera with an E2V 1024x1024 CCD in it. The guide camera is located on a radial stage and is pointed at a diagonal pickoff mirror that is itself located on a stage on top of the radial stage to allow independent focussing of the guider.


At the NA2 port, a single-object, multi-channel (UBVRI) photometer has been built at NMSU. This uses photomultiplier tubes for UB and avalanche photo-diodes for VRI. Light from the telescope hits a diagonal mirror with a small hole in it that allows light into the photometer. The rest of the field is imaged using an APOGEE 7P camera which has a 512x512 SITe CCD; the pixel scale is about 1.6 arcsec per pixel. There are no filters in front of this camera. It is used for object acquisition and subsequent guiding (on a field star).


In the 1m control room at APO, there is currently one computer: command1m, a Dell 3.2 Ghz Pentium D PC, which runs the Linux operating system. command1m is the main computer used for operating the 1m. A variety of software, including IRAF, xvista, TeX/LaTeX, etc. is available. On command1m, users should use the tcomm account; for the current password, check with Jon Holtzman. The normal mode of observing is that a VNC server is run on command1m , and all of the observing programs are run out of this server. See section 2.2 for instructions on how to start/kill the VNC server and how to connect to it.

Another computer, ccd1m, is located in the computer room in the main building. This computer controls the NA1 camera via a custom card and fiber optic connection, the guide camera via a USB port (through a fiber extender to the dome), and 3 remote video Webcams (through USB ports).

Dome computers

In the dome, there is a rack which holds the telescope control hardware. The left side of rack holds the main power switches for the telescope/dome, the telescope motor controllers, the guider/tertiary motor controllers, and the weather station. The right rack holds two PCs which control the telescope/guider and the APOGEE photometer acquisition camera. The two PCs are:

There is a single monitor and keyboard in the rack that can be used with either computer, but the cables need to be plugged into the computer you want to look at.

Emergency telescope control

There are two emergency stop buttons in the dome: one on the pier across from the door, and another small which controls the power strip at the top of the left side of the power rack. Please identify the locations of these buttons before using the telescope. Hitting this button will kill power to the telescope and dome motors and should immediately stop the telescope and dome. This should be done if there is ever any question about whether the telescope is moving safely, or is about to run into something or someone. If the situation requires that you hit the emergency stop button, you must contact Jon before restoring power and using the telescope; after hitting the stop button, the telescope will be lost and not be aware of the fact that it is lost, which can be a very dangerous situation. Hopefully, you will never need to hit this button.

Emergency stop is also available through computer control using the power program which is automatically started when the telescope control suite (tcomm) is started.

If you kill the motor power with the dome open, the dome will automatically close (so long as there is site power). Note that the software will not be aware that the dome has closed if this happens.

WARNING about manual telescope motion

Although it is possible to move the telescope manually, this should not be done if it can be avoided. Always move the telescope using computer control, unless instructed otherwise. The reason for this is that it is possible with an alt-az telescope to have cable wrap-up problems, which can be avoided only if the software accurately can keep track of where the telescope is. If the telescope is moved manually, the software won't know about it, and it may then command moves which will cause trouble. This is especially true for the rotator, which has no limit switches at all, and consequently its state of wrap is monitored by software only.