Stoking the star-maker machinery
We had the sky, up there, all speckled with stars, and we used to lay on our backs and look up at them, and discuss about whether they was made, or only just happened – Jim, he allowed they was made, but I allowed they happened; I judged it would have took too long to make so many – Mark Twain, Adventures of Huckleberry Finn, 1884.
Karen A. Newman
They’re making stars in Chile, Huck,
and it did take a long time – about 10 years – but overnight on Jan.
21-22, there were five new stars in the Southern sky. You wouldn’t have been
able to see them with your eyes, but they were there.
Forgive me for mixing my cultural references, but with apologies
to Joni Mitchell and Mark Twain, their words just seem to fit. The team at the Gemini
South telescope in Chile successfully propagated a 50-W laser producing five laser
guide stars, as we reported at Photonics.com on Feb. 2. The new constellation will
be used to sample atmospheric turbulence for the Gemini Observatory’s GeMS
GeMS, for Gemini Multi-Conjugate Adaptive Optics System, will
allow relatively wide-field imaging at extremely high resolution over an exceptionally
large portion of the sky. The system is expected to provide very sharp images of
similar quality to those obtained from space. For an explanation of multiconjugate
adaptive optics and how it differs from adaptive optics, see the MCAO primer at
the Gemini Observatory website (http://sciopsedit.gemini.edu).
Those of us who marveled at the beginnings of space exploration
in the second half of the past century still gaze up at the night sky and wonder
how the stars came to be. It is exciting to think that the work going on at the
Gemini Observatory may bring us closer to an answer for Huck and Jim, and for all
According to the Gemini South team, technical tests of the laser
and the GeMS will continue throughout 2011 and are expected to be available for
scientific use next year. The days ahead at Chile’s Aura Observatory are sure
to be filled with exciting events that will be anticipated and celebrated, and we’ll
look forward to amazing images and new knowledge about our universe in the years
Looking ahead just a little, you will find Photonics Media this
month at OFC/NFOEC in Los Angeles on March 6-10; at Pittcon in Atlanta on March
13-18; and at Automate in Chicago on March 21-24. I myself will be at Automate,
checking out all the latest advances in machine vision. I hope to see you there.
- adaptive optics
- Optical components or assemblies whose performance is monitored and controlled so as to compensate for aberrations, static or dynamic perturbations such as thermal, mechanical and acoustical disturbances, or to adapt to changing conditions, needs or missions. The most familiar example is the "rubber mirror,'' whose surface shape, and thus reflective qualities, can be controlled by electromechanical means. See also active optics; phase conjugation.
- atmospheric turbulence
- Irregularities and disturbances in the atmosphere that are of particular interest because they induce random temporal and spatial phase and amplitude fluctuations that destroy the optical quality and the coherence properties of laser beams.
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