The TURPOL page
The Turku UBVRI Photopolarimeter (Turpol) was built at Turku Observatory by V. Piirola, based on his earlier design of such a photo-polarimeter. The current version has been in use at the NOT since March 1989.
TurPol is no longer offered.
Turpol Operations Manual:
(NB! Old version from 1999!)
Use the links below. Procedures have changed.
General Turpol info:
Turpol Schematic Layout
Principle of Operation
UBVRI bands from dichroic mirrors
Neutral density filters
Signal to Noise Plot
Photos of Turpol
Observing with Turpol:
Start-up in the evening
How to observe
How to use the ST-4 for diaphragm viewing.
Close-down in the morning
High (linear) polarisation standards
Unpolarised/Polarised standard stars
from Turnshek et al. 1990, AJ 99, 1243. See also
Example of data acquisition file
. New addendum for circular polarimetry mode:
A few useful reference papers
Staff set-up procedures (Staff only!):
Set-up during first night
TurPol Cooler Manual
Instructions on how to mount TurPol filters
Polarization standard star project (2008-2009)