Imaging the Invisible
with Grainger Observatory's stellar new robotic telescope

The spheres were in alignment this February, for the Academy's new robotic telescope was up and running just in time for science instructor Chris Harper's astronomy classes to use it on a newly discovered star. With the new telescope, Harper's students were able to collect and study digital images of Supernova 2002ap, which would have been difficult, if not impossible, to see through the observatory's other telescopes.

The Academy's Grainger Observatory is a member of the American Association of Variable Star Observers, a worldwide interface between professional and amateur astron-omers. Harper believes that "one of the great things about the astronomy program at PEA is that it is a science in which students can really make observations that are valuable to professionals in the field."

Adding the telescope to the Academy's constellation of instruments has meant a great deal of collaboration between astronomy instructors Harper and Emily James, who wrote the grant proposal and shepherded the project, their students, members of the information technology and facilities management departments, and Jerry Gunn, an outside specialist who designed the telescope's systems. The Grainger Foundation, which had made possible much of the existing observatory and its equipment, agreed to fund it.

A third dome at the observatory

A third dome at the observatory The robotic telescope makes the third and central "dome" at the observatory, though its roof is a pyramid. The eight-inch reflector telescope's automated dome, robotically controlled mount and charged coupling device (CCD) camera are all connected to the Academy network. All of these systems can be operated from a computer in the dome or from terminals in the chart house and Phelps Science CenterÑor conceivably from anywhere in the world. Operating a telescope from indoors is a novelty for PEA astronomers. When the telescope was first being tested from the chart house, one of Harper's students said it "felt like cheating" to be warm and indoors while making a mid-winter observation.

The robotic telescope has a narrower field of view than the other two large telescopes on campus. But the precision of its electronically controlled movement, its ability to automatically slew, or swivel, to and track an object in the sky and the camera's very efficient use of available light (it captures 90 percent, as opposed to the 15 percent captured by a normal camera) make it a valuable specialized tool. To find an object in the sky, the operator can select from an existing "menu" of hundreds of objects that Gunn has programmed into the system, or enter coordinates from a star chart. The robotic system automatically opens the dome and moves the telescope into position; the CCD camera makes digital images on command. A weather station in the dome detects cloud cover, wind speed, available light and temperature to prevent damage to the telescope or the dome when it is being operated remotely. While the operator does not get a live picture of what the telescope is "seeing," the digital images it takes are instantly visible on the computer.

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