The 0.9-meter telescope is a Cassegrain telescope mounted on an off-axis asymmetrical mounting and used on the east side of the pier. This telescope is at present only used for direct imaging with a dedicated 2048x2046 CCD detector. A CCD-based autoguider, which looks at a small off-axis field, is permanently installed. From Feb 1 2003 the 0.9-m is one of the CTIO small telescopes being operated by the SMARTS Consortium.
Classical observing only. Historically, there has also been service observing, but this is not available due to financial constraints.
Since 2000, the 0.9-m has been equipped with a dedicated 2048x2046 Tek2K CCD detector. Please refer to the Tek2K instrument page for CCD characteristics.
The standard filter size for the 0.9m CFCCD is 3x3 inch. The filters are mounted in two filter wheels which each can hold up to 8 filters. Usually, 2 positions in each wheel are taken up by a color balance filter (for dome flats) and the "clear" position. We also have a single wheel which can hold up to five 4x4 inch filters. This filter wheel can be installed in place of one of the 8-position wheels.
See the Filter list for more information on the available filters.
For projects that require accurate timing information, here is a quick overview on how the time ends up in the image headers:
There are two different header entries relating to time, UT and UTSHUT. UT is read from the TCS. While there is a GPS receiver that displays accurate Universal Time in each telescope's console room, this information is currently not communicated to the TCS automatically, but instead has to be manually entered at the beginning of each night. The absolute accuracy is therefore at best ~1 sec. In addition, the TCS clock often drifts by a considerable amount during the night and is therefore not reliable for both absolute and relative timing.
UTSHUT is taken from the ARCON controller's clock, which is synchronized against the SUN data acquisition computer's clock every time ARCON is started up. After that it runs on the controller's internal clock. The UTSHUT timestamp is the time when the shutter opens and should provide the most accurate timing information currently available. The SUN computer's clock is synchronized with the time reported by the US Naval Observatory and other internet sites (the details of this process are given here). Occasionally, e.g. after a power outage or network problems, this synchronization process fails and it is important to check the accuracy of the SUN clock at various times during a run by visually comparing it to the GPS time display.
To check for the correct UT time on the web, try this link to the USNO Master Clock .