Recently, the Scientists from the University of Crete, Greece, Caltech, USA, Inter-University Centre for Astronomy and Astrophysics (IUCAA), India, the South African Astronomical Observatory and the University of Oslo, Norway, are involved in PASIPHAE Project
About PASIPHAE Project
- It is Polar-Areas Stellar-Imaging in Polarisation High-Accuracy Experiment.
- It is an international collaborative sky surveying project.
- Its name is inspired from Pasiphae, the daughter of Greek Sun God Helios, who was married to King Minos.
Key Features of PASIPHAE Project
- Scientists aim to study the polarisation in the light coming from millions of stars.
- The survey will use two high-tech optical polarimeters to observe the northern and southern skies, simultaneously.
- It will focus on capturing starlight polarisation of very faint stars that are so far away that polarisation signals from there have not been systematically studied. The distances to these stars will be obtained from measurements of the GAIA satellite.
- By combining these data, astronomers will perform a maiden magnetic field tomography mapping of the interstellar medium of very large areas of the sky using a novel polarimeter instrument known as WALOP (Wide Area Linear Optical Polarimeter).
Why is PASIPHAE Project is important?
- The PASIPHAE survey will measure starlight polarisation over large areas of the sky.
- This data along with GAIA distances to the stars will help create a 3-Dimensional model of the distribution of the dust and magnetic field structure of the galaxy.
- Such data can help remove the galactic polarised foreground light and enable astronomers to look for the elusive B-mode signal.
What is WALOP?
- Wide Area Linear Optical Polarimeter (WALOP) is an instrument, when mounted on two small optical telescopes, that will be used to detect polarised light signals emerging from the stars along high galactic latitudes.
- A WALOP each will be mounted on the 1.3-metre Skinakas Observatory, Crete, and on the 1-metre telescope of the South African Astronomical Observatory located in Sutherland.
- Once built, they will be unique instruments offering the widest ever field of view of the sky in polarimetry.
- WALOP 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. That is, each star will have four corresponding images which when stitched together will help calculate the desired polarisation value of a star.
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