Earthshine blog

Earthshine blog

"Earthshine blog"

A blog about a system to determine terrestrial albedo by earthshine observations. Feasible thanks to sheer determination.

Altair maps the stellar psf!

Exploring the PSFPosted by Chris Flynn Oct 02, 2011 08:23AM
We took a few hundred 0.4 second exposures of Altair, to measure the stellar PSF. Plot below shows Altair (green) versus our current best model (red) of the PSF based on fitting the moon. Note x axis is log(r/pixels).

The match is excellent, especially for the outer halo with its r^-3 powerlaw! Disagreement in the inner PSF (r<3 pixels, log(r)<0.5) is because Altair is very elliptical -- so the radial PSF shown here has a lot of scatter. Note that this might be due to saturation/miscentering during the coadd - we'll look at that.

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