Blog

The mirror is Flat

Thanks to the hard work of Armando, Marco and Runa the Magellan ASM has had its first round of flattening with the 4D interferometer in the test Tower. It took only one day from start to finish. The shell flattened very well, except in the central area which is hidden from light by the Magellan telescope’s central obscuration, so it does not matter.

The first flat of the Magellan adaptive secondary

Into the Test Tower!

Today we raised our hexapod-mounted adaptive secondary mirror (ASM) into the Arcetri test tower in Florence, Italy.  The large tower will allow us to operate the secondary at the same focal length and optical conjugates as the Magellan telescope in Chile.  We’ll use this test setup to interferometrically test the performance of our ASM and to close the loop on our full AO system.

The Arcetri Test Tower
The Arcetri Test Tower
The concave ellipsoidal ASM with a retroreflector mounted at its short conjugate is raised into the tower.
The concave ellipsoidal ASM with a retroreflector mounted at its short conjugate is raised into the tower.
A grad student magnified by the F/1.1 ASM
A grad student magnified by the F/1.1 ASM
Armando Riccardi trapped inside the looking glass!
Armando Riccardi trapped inside the looking glass!
The Ring anyone?
The Ring anyone?

92% Strehl Sloan r’ Image

The below image is our 92% Strehl Sloan r’ band image with our triplet ADC and dichroic beamsplitter in the beam.  The slight elongation of the PSF and the asymetric contrast of the fringes are due to the “zenith spike” effect of the ADC.  This effect is predicted by our models and will not manifest itself on-sky when the atmosphere will counteract the residual chromatism of the ADC.

Spot diagram showing the broadband chromatic "zenith spike" effect of the ADC in the lab.

Our Mirror is a Mirror

On March 10, 2011 the MagAO secondary shell had its frontside successfully aluminized at the University of Arizona, Steward Observatory coating facility in Tucson by Richard Sosa and Gary Rosenbaum. This also took a lot of hard work by Jason Lewis and Victor Gasho.

Magellan ASM side view
The side of our freshly aluminized 850 mm diameter adaptive secondary for MagAO. This shell is just 1.5mm thick with 585 magnets glued on the back.
The Magellan ASM
The newly coated front of the secondary.
Victor and the ASM
Project Manager Victor Gasho reflected in the secondary
Laird and the ASM
A relieved Principal Investigator Laird Close reflected in the secondary.