Author(s): , , ,
Institution(s): 1. University of New South Wales
Detections of polarised light from exoplanets are an important expansion of exoplanet studies, as they provide a complimentary and advantageous diagnostic to the other characterisation methods. However some of the earliest claimed detections of polarised light from exoplanets are disputed.
The High Precision Polarimetric Instrument (HIPPI) is currently the highest sensitivity astronomical polarimeter (Bailey 2015) in the world at 4.3 ppm or better precision, and has been used to observe exoplanet systems including the disputed first detection source (Berdyugina 2008, Wiktorowicz 2009, Berdyugina 2011), HD189733b. HIPPI is designed for best sensitivity in blue light where Rayleigh scattering would produce a strong signal for hot Jupiter planets (Burrows 2008). These observations, taken at the Anglo-Australian Telescope in 2014 and 2015, are compared to models from a polarised light adaptation of the Versatile Software for the Transfer of Atmospheric Radiation (VSTAR).
Our new, independent Hot Jupiter polarised light detections are discussed, including the physical sources of the detected polarised light, as well as additional contributing factors (e.g. debris, ISM anomalies). For HD 189733b we use available visible and near infrared transit and polarimetric data to create and interpret a planetary portrait using VSTAR.