PlanetPol was a ground-based, high sensitivity
polarimeter based at the
William Herschel Telescope[1] on the island of
La Palma in the
Canary Islands,
Spain that has now been decommissioned. It was the most sensitive astronomical visual polarimeter ever built in fractional polarisation, a mantle that since its decommissioning now belongs to
HIPPI. Although the device could be used for a wide range of astronomy, its primary use was the
detection of extrasolar planets.[1]
Results
PlanetPol did not discover any extrasolar planets, however it was used to provide upper limits to planetary albedos in the known
55 Cnc and
τ Boo planetary systems.[2] Observations with the polarimeter in the Canary Islands, which are affected by dust from the Sahara, also identified airborne dust as a source of polarization within our atmosphere.[3] Additionally, PlanetPol provided measurements of the polarization of a few dozen nearby stars,[4] which were later combined with southern hemisphere measurements from PlanetPol's successor, HIPPI,[5] to provide information about the nature of those stars and the distribution of the interstellar medium.[6]
^Bailey, Jeremy; Kedziora-Chudczer, Lucyna; Cotton, Daniel V.; Bott, Kimberly; Hough, J. H.; Lucas, P. W. (2015-04-08). "A high-sensitivity polarimeter using a ferro-electric liquid crystal modulator". Monthly Notices of the Royal Astronomical Society. 449 (3): 3064–3073.
arXiv:1503.02236.
Bibcode:
2015MNRAS.449.3064B.
doi:
10.1093/mnras/stv519.
ISSN1365-2966.