Daily Image

Click here or on the picture for a full size image.

A heart transplant for ZIMPOL

Submitter: Johan Pragt
Description: The heart of the ZIMPOL instrument is an FLC. Over the last 2 years ZIMPOL ‘lived’ with FLC#3, but recently we gave it a new heart (FLC#4).

FLC stands for Ferro Liquid Crystal. It is like a LCD computer screen with just one huge (20mm diameter) pixel. The latter has an unusual optical property, i.e. a differential polarization error as small as 1 nanometer. The FLC rotates the polarization of the incoming light from a star-planet system with a rate of up to 1 kHz, synchronized with the read-out rate of the detector. With this trick, polarized light from the planet can be distinguished from the un-polarized light of its star.

SPHERE-ZIMPOL is a high-precision imaging polarimeter, operating in the visual range. It is one of the three focal instruments of SPHERE, the ‘Planet Finder’ Instrument for the VLT in Chile. It is developed by a consortium of the University of Amsterdam, University Utrecht, ETH Zürich and NOVA-ASTRON.

ZIMPOL is in its final test phase at ASTRON, and almost ready to be shipped for integration with SPHERE. The latter is in the "PAE" (Preliminary Acceptance Europe) phase. Shipment to Grenoble (France) is planned for the end of 2011. Integration with SPHERE will be finished in the first quarter of 2012. The entire SPHERE instrument will then be commissioned on the VLT in early 2013. For more information, please see http://www.eso.org/sci/facilities/develop/instruments/sphere/
Copyright: Credits: Daniel Gisler (ETHZ), Menno de Haan, Ronald Roelfsema (NOVA-ASTRON)
  Follow us on Twitter
Please feel free to submit an image using the Submit page.