This is a followup to the previous post on the V and B band PSFs.

Here is the stellar profile of Arcturus, shown in B (blue) and V (green). Clearly the B band light has a different core to the PSF than V.


Arcturus data were taken on the night of 2011-03-22. The files used are

align_stacked_2455643.4800437Arcturus-B-FILTER.fits align_stacked_2455643.4891739Arcturus-V-FILTER.fits

Oddly, the V band data are affected by what we called “shutter bounce” — a non-axisymmetric feature to the right (along crows in the CCD) of the PSF, but the B band data show no sign of such a bounce (the PSF profile can be exceedingly cleanly centered, unlike V band). No explanation for this for the moment!

Here are the other bands, all compared to V (green symbols):


PDF version here:


pdf

Here are the same profiles, this time with the data averaged into radial bins. The solid green line is the V band profile in each case.

VE1 and V are very similar — but this is what we would expect. IRCUT is not too far off V either.. the B and in particular the VE2 filters differ significantly from V. The difference between VE2 and all the other filters is huge, so we need to look into that next!