The Modernization of Behlen Observatory



On the left you can see the detector used on the telescope in the late 70's and early 80's called a photometer. It was used to measure the brightnesses of stars one at a time. To the right is a detector called a CCD (Charge Coupled Device) which was used during the late 80's and throughout the 90's. It is basically an electronic camera that measures and outputs numerically the brightnesses of (390 x 584) locations all across the field the telescope is observing. It allows one to observe several stars at once and it detects photons (particles of light) with much greater efficiency than our eyes do.


To the left one can see a liquid nitrogen dewar connected to the CCD. It is necessary to cool the detector to observe faint objects. To the right one can see the metal box which contains a readout of the CCD temperature. We start observing when the temperature reaches -100 degrees Celsius.


To the left one can see our filter bolts. These contain squares of colored glass which only allow certain colors of light through to the CCD. The bolt can slide back and forth underneath the telescope. Thus, we can measure the brightnesses of stars in different colors. To the right is a picture of our data room. Our telescope operation is highly automated requiring very little human interaction. The pointing of the telescope, the sliding of the filter bolts, and the taking of CCD frames is all done by computer.


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