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The Macalester College Observatory
The Macalester College Observatory is a science-grade facility. Our 16-inch reflecting telescope, custom-designed and built by DFM Engineering, points and tracks elements of the night sky with remarkable, repeatable precision. This telescope, furthermore, that can be used for meaningful scientific research projects. In all respects it looks and acts just like the large (2 to 4-meter) telescopes at the national facilities (e.g., Kitt Peak National Observatory). It is computer controlled and computer driven so that at all times you can know exactly where the telescope is pointing and exactly how well the telescope is tracking. Also, the observatory dome is automated so that the telescope is always pointing out of the slit. The operating system parallels those used to operate the large telescopes so that students trained on this system will experience observing as though they were at a national facility. Nevertheless the observer is still responsible for watching the weather! The telescope is also interfaced with TheSky IV (Software Bisque). TheSky includes every celestial object down to the 20thmagnitude, and the telescope can automatically move to whatever object you point at and click on (assuming it's above the horizon and in the seasonal sky). What this means is that now we can look at the stars instead of looking for them! Currently, we have an SBIG ST-8 CCD as our imaging camera (Santa Barbara Instruments Group, CA). A science-grade CCD camera is a microscopic layer of silicon divided into rows of pixels. Each pixel records photons of light received as an electrical pulse, which is then read at the end of the exposure. Our CCD is divided into 1530 rows and 1020 columns, gives us 1,560,600 pixels with which to build an image. The ST-8 CCD has an active area of 13.8 by 9.2 mm, which allows us to take images with a larger field of view. Using CCDOPS (Software Bisque), we can expose the camera, capture an image, and then reduce and analyze it by computer. A CCD camera is necessary for any decent astronomical imaging in our urban site; not only is the CCD very sensitive to scant amounts of light, it also has additional features such as co-adding several images to improve the signal-to-noise of an image and dividing out sky background light. TheSky and CCDOPS are run on a Pentium II 450 MHz PC computer. This computer is not located in the observatory itself; instead it is located in the astronomy lab room one floor below. This has the advantage that observers can stay warm on those freezing cold Minnesota winter nights, but we also have a Cybex connector and additional monitor, keyboard, and mouse in the observatory which run off the PC computer for those few nice warm fall and summer nights (as well as the obvious necessity of setting up at the beginning of the night). TheSky and CCDOPS run under Windows98, but our PC computer also runs under Linux and has a JAZ drive and HP color printer as peripherals. The telescope runs from its own computer which is linked to the PC. |
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 From Telescope installation 1998.
NASA image of the Hubble Deep Field, imaged in f450, f606, and f814. Copyright NASA. |
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