The MODS Squad: Searching for Distant Stars

Astronomer Rick Pogge breathed a sigh of relief when the MODS1 (Multi-Object Double CCD Spectrographs/Imagers) Unit was safely crane-lifted from its basement home, loaded on a truck and shipped to Mt. Graham, Arizona, in early May. He and his team had been working on it for a decade.

The MODS project is Ohio State’s major contribution to building the Large Binocular Telescope (LBT). Ohio State is one of five international partners on the LBT project, which, when fully-operational, will be capable of image sharpness 10 times that of the Hubble. “What this means to astronomers is incredible,” Pogge said. “We will be able to see deeper into the Universe than we thought could be possible.”

Earlier in the week, the LBT Corporation announced a major breakthrough using adaptive optics. Pogge, who will be in Arizona until the end of June, is quick to disavow credit, “I have no involvement in that work. I’m just an impressed bystander and future user of the system. The results they showed on the star cluster are spectacular and hold up a great deal of promise for what the telescope can do. What the Adaptive Optics system does is follow how starlight is distorted by atmospheric turbulence, and then uses actuators to distort the secondary mirror of the telescope to compensate.

“What I’m doing up here is working on MODS1 re-assembly in the lab, a mostly messy technical task with lots of tedium and rolling about on the floor getting at bolts and cables and such—very far removed from the beautiful adaptive secondary work outlined in that press release.”

MODS1 will be installed on the telescope in September and science operations will begin in the spring of 2011. Back in the basement, work has already begun on MODS2, a mirror-image of MODS1. “This should only take a year or so to build as most of the kinks have already been worked out, or they should have been,” Pogge laughed.

When finished and installed, the MODS instruments will work in tandem to exploit the full 11.8-meter effective aperture of the twin LBT mirrors. Real workhorses, capturing light reflected by the LBT mirrors, MODS will allow astronomers to analyze distant stars and galaxies.