Let there be light

And there was light.

It took us about a week of a very tedious and boring work, but we finally managed to get it done: all of the optical elements (that is: the two mirrors) of the payload are now aligned (well, sort of…). The springs used to  adjust the secondary mirror have been removed, and replaced with peelable washers (I’ll dedicate a specific post to those ones, they deserve it…). Everything is now hold in place by three brand new FHC M3x8 screws, coming straight from the observatory warehouse. By the way, I wonder how many PhD student at LESIA know this place…

With all the optics properly aligned, it it time to get the first serious image of the Point Spread Function (aka PSF) of the PicSat instrument. According to the theory, the PSF should be very close to a 2d gaussian of about 5 or 6 microns (Full Width at Half Maximum).

Starting scan:

[====================] 0%  (the piezo actuators are now purring)

[====================] 50%

[====================] 100%


Annnnd… here it is! Oh, wait a minute, is it really an 8×12 micron spot that I see here? And is that a secondary lobe over there?

I knew we should have gone for a Cassegrain!

The image of a point source (a single star), as seen by the fiber in the focal plane of the PicSat telescope.

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