Quote:
Originally Posted by gb44
Very interesting Stephan.
The interferogram is pretty bad. Surely that mirror wouldnt have passed at the QC stage in the factory. Maybe the marks show it went back and forth but scraped through in the end. Could have resulted from bad annealing.
GlennB
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I don't know what the cutoff point for the factory QC was, but the RMS value of the wavefront error seems better than one tenth of a wave, or 45nm, which may have been deemed acceptable.
If you open up the image and cover the bottom right of the interferogram, where the maximum departure is, the rest is not too bad. The wiggles don't seem to be more than one quarter of a fringe.
The anomaly will produce flares on brighter stars but it should not produce elongated stars because it represents a small portion of the total area of the aperture.