Astronomical Polarimetry with CCD, sCMOS and EMCCD Cameras

In this webinar, Dr Eoin O’Connor, Dr Andrzej Piascik and Dr Éamonn Harvey will each talk about their experiences and projects involving astronomical polarimetry. At first, Dr O’Connor will describe the design, use and results of the Galway Astronomical Stokes Polarimeter (GASP) to observe rapidly varying astronomical sources. The GASP instrument is a dual-beam, division of amplitude, imaging polarimeter and uses two Andor iXon Ultra 897 EMCCDs and has been used on the WHT, the ESO 3.6m Telescope and Gemini South.

The second presentation by Dr Piascik will describe the design of the Multicolour OPTimised Optical Polarimeter (MOPTOP), a prototype imaging polarimeter for the robotic 2-metre Liverpool Telescope located on La Palma. This is a fourth generation polarimeter and it supersedes a previous instrument, RINGO3, with the aim of improving sensitivity and accuracy of astronomical polarimetric measurements. It combines science grade sCMOS cameras, a rotating half-wave plate and a wire grid polarising beam-splitter in a dual-beam arrangement.

Dr Harvey will then present the Galway Liverpool Imaging Polarimeter (GLIP) concept, which has been developed in partnership with researchers at the National University of Ireland Galway (NUIG). The GLIP concept builds on division of amplitude polarimetry with GASP, developed at NUIG and cost effective high-time resolution use of sCMOS detectors for polarimetry with MOPTOP by LJMU.

Learning Objectives:

• Lessons learned from the projects GASP, the RINGO series and MOPTOP.
• Instrument design and calibration methods.
• Difficulties arising in harsh observing conditions.
• Building for the future, the why and how of accurate full Stokes, full colour polarimetry with no moving parts.