Saturday, November 9, 2013


Well, I took my own advice from our last post.  Last night was the last night of the first engineering run of ARGOS, the Advanced Rayleigh guided Ground layer adaptive Optics System. It will allow making artificial guide stars to partially correct atmospheric turbulence.  Since it won't be in use again until next Spring, Melinda and I took off for the Willcox area - where the observatory is readily visible and closer than the view we got from Mount Lemmon Wednesday...

But also more visible, the moon had grown 2
days brighter and partially affected the visibility.  While we were about half the distance (about 20 miles due south) to the Large Binocular Telescope, the brighter sky partially hid the beam, though I was convinced that I could barely see it naked eye.  It was, of course, evident in binoculars from the fallow field where we set up...  These wide-field images, while apparently illuminated as bright as day in the long exposures, approximates the view of the laser - I could follow it in binoculars nearly up to Polaris as shown here.  The bright sodium lights at left is the prison Fort Grant, a mere 6 miles (and a mile below) the Observatory.  The picture at right shows the 2 lenses I had set up - a 70-200 zoom at left shooting 60 second exposures, and the William Optics 11cm APO refractor at right taking 2 minute exposures.  Clicking on either will load the full-size images and the laser will be visible...  Both of these pictures were taken with the Canon 10-22 zoom, the one at left near 20mm, the one at right near 10mm...

Both setups took nice images of the
mountaintop.  The wider 200mm showed a wider field of the mountaintop and caught several cars going up and down the mountain, though not in this particular frame at left.  It is a 60 second exposure at F/3.5, and shows the LBT structure and the twin beam, one for each of the primary mirrors of LBT.  The shot at left is from the 11cm F/7, so 770mm of effective focal length and is a 2 minute exposure.  It shows not only the LBT structure and laser scattering from the interior of the building, but to the left of it is the moon reflecting off the dome of the Vatican Advanced Technology Telescope (VATT), a 1.8 meter (72") telescope also built at the Mirror Lab.  Dimly visible between them (if you look at the full image) is the Sub-Millimeter radio Telescope (SMT).  Each beam actually consists of 3 beams that map out  the turbulence over a wider field of view, but they can't be resolved from 20 miles.  For more close-up pics, info and links, visit the LBT news blog.

It is fun seeing the developments in this product of the Mirror Lab and the first two 8.4 meter mirrors that I had a hand in polishing.  It would be great being on site during the next round of testing - will have to ask some favors and see if I can be up there next Spring!

1 comment:

Steve West said...

Great job catching the lasers. Really cool.