Sun Cycle : It Has Observatory Workers on the Spot

After more than 53 years of getting up close and personal with the sun, the solar telescope at Griffith Observatory was overdue for a major overhaul. In 1991, the 11-year cycle of sun spots will peak, and the telescope--installed when the observatory was opened in 1935--is being readied to take full advantage of the event.

The solar telescope is a triple-beam coelostat with three drive mirrors tracking the sun. These drive mirrors reflect the sun’s image through a series of other mirrors down to the observatory’s lobby and onto a ground glass screen.

The telescope’s overhaul includes applying new coats of aluminum to its mirrors, replacing drive motors, painting towers, lubricating and adjusting the dome’s shutters and rewiring a control box.

Observatory officials project that the work will be completed in August.

Astronomers are already noticing bigger sun spot eruptions, three years before the activity reaches its peak. With the solar telescope, visitors to the observatory will be able to see some spots as large as 300,000 miles long.