Optical Polarisation Study of Galactic Open Clusters
Namita Uppal,
Astronomy and Astrophysics division, Physical Research Laboratory, Ahmedabad-380009,India and Department of Physics, Indian Institute of Technology, Gandhinagar-382355, India. Corresponding author: namita@prl.res.in, namita.uppal@iitgn.ac.in
Shashikiran Ganesh,
Astronomy and Astrophysics division, Physical Research Laboratory, Ahmedabad-380009,India
Santosh Joshi,
Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital-263001, India
Mrinmoy Sarkar,
Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital-263001, India
Prachi Prajapati,
Astronomy and Astrophysics division, Physical Research Laboratory, Ahmedabad-380009,India
Athul Dileep,
Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital-263001, India
Abstract
Dust is a ubiquitous component in our Galaxy. It accounts for only 1% mass of the ISM but still is an essential part of the Galaxy. It affects our view of the Galaxy by obscuring the starlight at shorter wavelengths and re-emitting in longer wavelengths. Studying the dust distribution in the Galaxy at longer wavelengths may cause discrepancies due to distance ambiguity caused by unknown Galactic potential. However, another aspect of dust, i.e., the polarisation of the background starlight, when combined with distance information, will help to give direct observational evidence of the number of dust clouds encountered in the line of sight. We observed 15 open clusters distributed at increasing distances in three lines of sight using two Indian National facilities. The measured polarisations results used to scrutinize the dust distribution and orientation of the local plane of sky magnetic fields towards selected directions. The analysis of the stars observed towards the distant cluster King 8 cluster shows two foreground layers at a distance of ∼ 500 pc and ∼ 3500 pc. Similar analysis towards different clusters also results in multiple dust layers.
Keywords : Multiple Stellar Systems, polarisation observations, data reduction, dust distribution
Pour citer cet article
Namita Uppal, Shashikiran Ganesh, Santosh Joshi, Mrinmoy Sarkar, Prachi Prajapati & Athul Dileep, «Optical Polarisation Study of Galactic Open Clusters», Bulletin de la Société Royale des Sciences de Liège [En ligne], Volume 93 - Année 2024, No 2 - Proceeedings of the 3rd BINA Workshop on the Scientific Potential of the Indo-Belgian Cooperation, 155-169 URL : http://popups.ulg.be/0037-9565/index.php?id=11636.
