PASIPHAE: A Sky Surveying Project

PASIPHAE: A Sky Surveying Project

Part of: GS Prelims and GS -III – Sci & Tech

In news

• The Wide Area Linear Optical Polarimeter (WALOP) is being developed at Inter-University Centre for Astronomy and Astrophysics (IUCAA), India.
  • WALOP is a vital instrument for the PASIPHAE Project.
  • Polar-Areas Stellar-Imaging in Polarisation High-Accuracy Experiment (PASIPHAE) is an international collaborative sky surveying project.

About the PASIPHAE Survey

• It is an opto polarimetric survey 
• It aims to measure the linear polarization from millions of stars.
• The survey will use two high-tech optical polarimeters to observe the northern and southern skies, simultaneously.
• The survey will be conducted concurrently from the South African Astronomical Observatory in Sutherland, South Africa in the southern hemisphere, and the Skinakas Observatory in Crete, Greece, in the north.

Importance of the Project

• It will be used to perform magnetic tomography of the Milky Way Galaxy.
  • Tomography is a technique for displaying a representation of a cross section through a solid object using X-rays or ultrasound.
• It will deduce the 3-dimensional structure of the magnetic field and the dust that resides in the Galaxy.

About WALOP

• The WALOP will be capable of observing hundreds of stars concurrently present both in the northern and the southern skies.
• It will operate on the principle that at any given time, the data from a portion of the sky under observation will be split into four different channels.
• Depending on the manner in which light passes through the four channels, the polarisation value from the star is obtained.