Polarization Standards for IRCAL

For calibration you should also observe an unpolarized standard star. I've been using the list on this UKIRT web page but any nearby star should be unpolarized (i.e. no interstellar polarization). The UKIRT list is in 1950 coords and they're all high proper motion stars, so look up the new coords from SIMBAD or you can waste ten minutes trying to find a star in completely the wrong spot. The observation of the unpolarized standard star should be unsaturated - and can actually be done open loop since we're just doing aperture photometry on it.

There are also Serkowski polarized standards available on the same web page. I haven't found these to be all that useful for our purposes since most were measured with very large apertures (20" or larger) and it's often hard to compare the data to our spatially resolved polarimetry.

Here is a Lick-format target list containing these stars.


This page last updated by Marshall on 2005-12-08