Polarimetry

Information about the polarimeter can be found in the following document.

Instrument Focus

Please use the normal focussing GUI described in the Afternoon focus procedure

Cal Unit

You can use the cal unit to check the polarimeter. This unit has a set of polarizers.

Observing Scripts

The polarimeter is comtrolled by using command line scripts. They can be found in this section

Calibrations

Standard Calibrators
Standards star list name Comments
Polarized /kroot/starlists/0000_polarized Includes HST standards sorted by RA (listed first) followed by standards used by previous polarimetry experts
Unpolarized /kroot/starlists/0000_unpolarized
Imaging Photometric /kroot/starlists/0000_landolt.std.big Photometric flux standards are the same for LRIS and LRISp. Photometric flux standards are listed here.
Spectrophotometric /kroot/starlists/0000spectraphoto.stds Spectrophotometric flux standards are the same for LRIS and LRISp. Spectrophotometric flux standards are listed here.

Note that with some polarizing elements (HNP'B UV/optical Polaroid and teh IR800 IR polarizer), some of the wave plate positions will put all the light into one beam. Don't let yourself be fooled into doubling your exposure times and saturating the images at those angles. Arc Lamps Typical Exposure Times Flats Dome Flat Typical Exposure Times