On 19 October 2021, the School of Physical Sciences (SPS), Jawaharlal Nehru University, celebrated the 111th birth anniversary of the Nobel Laureate Prof. Subrahmanyan Chandrasekhar. To commemorate the outstanding achievements and contributions of Prof. S. Chandrasekhar in the fields of Plasma Physics, Astrophysics, Astronomy and Cosmology, the two-day long National Conference on “Waves, Instabilities and Structure Formation in Plasmas” was organized in a virtual mode. The main objective of this conference was to highlight and discuss the advancements in the areas investigated by Prof. S. Chandrasekhar, such as magneto-hydrodynamics (MHD), structure formation in interstellar media (ISM), hydrodynamic and hydro-magnetic stability, waves in plasmas, radiation transfer, dusty plasmas, degenerate quantum plasmas and many more. A total of 260 participants registered for the conference.

The conference began with the inaugural address delivered by Prof. M. Jagadesh Kumar, Hon'ble Vice-Chancellor, JNU. The keynote address was delivered by Prof. Bimla Buti (Founder, Buti Foundation and a former Ph.D. student of Prof. S. Chandrasekhar). She reminisced the time spent with Chandra during her Ph.D. and several other meetings thereafter. Prof. R. K. Chhajlani (Retired Professor, Vikram University, Ujjain) has presented the bio-sketch of Chandra and his significant scientific contribution in the diverse fields of plasma astrophysics. There were nine invited talks delivered by eminent plasma physicists, namely; Prof. Vinod Krishan (IIA), Prof. R. K. Chhajlani (VU), Prof. Amita Das (IITD), Prof. Avinash Khare (CUS), Prof. Durgesh Tripathi (IUCAA), Prof. M. K. Verma (IITK), Dr Pallavi Bhat (ICTS), Dr Kirit Makwana (IITH) and Dr R. Mukharjee (PPPL, USA). In four technical sessions, there were 11 oral and 21 poster presentations.

It gives us great pleasure to dedicate this special issue on “Waves, Instabilities and Structure Formation in Plasmas” to Prof. S. Chandrasekhar on his 111th birth anniversary. The original research papers appearing as a special issue in the Journal of Astrophysics & Astronomy have been peer-reviewed.

This issue contains articles on recent results in various fields in which Prof. Chandrasekhar made seminal contributions. Some of the representative subjects of discussion during the symposium are MHD turbulence, Jeans instability with cosmic rays, non-thermal steady solar plasmas, partially ionized plasmas, electron-acoustic waves, thermal instability, ultra-dense quantum fluids, Rayleigh–Taylor instability in quantum plasma, slow mode with time-dependent background temperature, ion-acoustic double layers in cometary plasma, solar wind plasma variations during Solar Cycles 22–24, waves in Hall thruster beam plasma, electrostatic waves in bounded quantum plasma, solitons, rogons and breathers in Jupiter’s magnetosphere, N-body simulation of galaxy merger and more.

It was evident from the in-depth and engaging discussions among the participants that the conference was an exciting and timely event. We are sincerely thankful to all the authors for their contributions to this special issue. We are grateful to Prof. Annapurni Subramaniam, Editor-in-Chief, Journal of Astrophysics & Astronomy for accepting our proposal to publish this special issue. We would also like to thank Ms. Shylaja for her patience and advice during the publication process.     

Ram Prasad Prajapati

Vinod Krishan

Guest Editors