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My first night laser spotting, July 27, 2002

Bob Havner


The 20-watt sodium laser seen making a beam from the dome of the Shane 3-meter telescope.

 

Tonight was my first night as a laser spotter for Lick Observatory. The adaptive optics system at the Shane 3 meter telescope utilizes a 20-watt sodium laser to put a false star in the sky. The system uses the star to compensate for atmospheric disturbances, creating sharper, clearer images of the objects observed.

The laser has the potential to temporarily blind a pilot should his aircraft accidentally fly into the beam. That's where laser spotters come in. It's our job to watch for low flying aircraft that frequently fly over the observatory. If a plane should come close to the beam we are responsible to notify the control room and if necessary shut down the beam.

I arrived at the Shane at 10:00 ready to go. Kostas Chloros is in charge of the laser team and who we are in contact with inside the telescope control room. Kostas gave me instructions on how to operate the communications system and the "kill" switch. After instructing Tina Kurth, the other spotter, we were ready to go. Kostas told us the direction that the beam would be pointing and, after we gave him the all clear, the yellow beam pierced the night sky.

The run lasts from 11:00 p.m. till 5:00 a.m. I brought my scope to take advantage of any down time and to see the guide star. As I looked along the beam I could see a tiny yellow "star" just beyond the end of it. To verify if it was actually the guide star, Kostas momentarily put the beam off-wavelength causing the star to blink out for a few seconds while the beam remained. Several people came over to see the guide star through the scope including Geoff Marcy who was speaking at the Music of the Spheres night at the main building. Geoff and his team are leaders in the discovery of extrasolar planets.

There were a few breaks throughout the night and the weather was fantastic. I was wearing only pants and a tee shirt till about 2:30 a.m. The observing was limited to only bright objects due to the bright Moon. At about 3:30 a.m. Saturn rose between Copernicus and Kepler Peaks. At the next break Kostas and Tina came over to see it. There was a very short run after that and it was time to shut down. The night flew by and dawn was beginning to show in the east. There was a room reserved for me at one of the dorms where I got a few hours sleep before heading down the mountain.

It was a great night.

 


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