Ricardo Salinas and Steve B. Howell
The Legend of Zorro Begins
In May, Gemini successfully commissioned Zorro, the
Observatory’s new dual-channel, dual-plate speckle
interferometer. Now permanently installed at Gemini
South, the instrument allows diffraction-limited speckle
imagery of binary stars, multiple stellar systems, Solar
System objects, and your own favorite target!
The atmosphere forgives no one. It does not matter whether you have a futuristic 30-me-
ter telescope or a more modest 1-meter telescope, your image quality will be domi-
nated and limited by the same factor: atmospheric turbulence. How can we overcome
the tyranny of the atmosphere to unleash the real potential (the diffraction limit) of a
telescope?
One solution is to circumvent the atmosphere altogether and put the telescope in orbit
— as evidenced by the breathtaking beauty of Hubble Space Telescope and other orbit-
ing astronomical observatory images, which testifies to the enormous appeal of this
solution. But as much as we would like to put Gemini in orbit, we simply can’t; this would
not only be very expensive, but above all, our technicians and engineers would really
hate their daily commute!
Reaching the Diffraction Limit from Earth
A different solution involving shorter commutes is the one given by adaptive optics. In
adaptive optics, the incoming wavefront, distorted by the atmosphere, is measured and
then corrected using deformable mirrors. One excellent example is the Gemini Multi-
conjugate adaptive optics System combined with the Gemini South Adaptive Optics
Imager, reaching near the diffraction limit in the K-band.
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GeminiFocus
July 2019