The Center of Excellence in Space Sciences India (CESSI) is a multi-institutional Center of Excellence hosted by the Indian Institute of Science Education and Research (IISER) Kolkata and has been established through funding from the Ministry of Human Resource Development. CESSI aims to explore the Sun’s activity, generate the understanding necessary for space weather forecasting, hunt for gravitational waves, support national space science initiatives, participate in international capacity building activities and pursue public-private partnerships in space science research. The Center will take advantage of high-performance computing facilities, cloud computing and the high-speed National Knowledge Network grid to achieve its goals.

CESSI faculty are drawn from IISER Kolkata, IISER Pune, Indian Institute of Astrophysics (Bangalore), Udaipur Solar Observatory-Physical Research Laboratory (Udaipur) and the Indian Space Research Organization (Bangalore), have wide-ranging interests in the astrophysical space sciences, and have the experience of handling international and national space science projects.

Since its inception CESSI has already contributed to major developments in astrophysics and space sciences. Notably, CESSI personnel are associated with the recently approved Aditya-L1 mission - India's first space mission to study the Sun. CESSI personnel contributed to the first direct detection of astrophysical gravitational waves from a binary Black Hole merger system and are involved with the LIGO-India mega project which aims to deploy a third gravitational wave detector in India to supplement the observations from the two detectors in the United States of America. CESSI affiliated personnel have also been involved with the planning and installation of India's most advanced ground-based solar telescope - the Multi-Aperture Solar Telescope at Udaipur Solar Observatory (Physical Research Laboratory) which has been operating since 2015. CESSI faculty are also playing important roles in national and international capacity building through their roles in working groups and committees at the International Astronomical Union (IAU), Committee on Space Research (COSPAR), Scientific Committee on Solar-Terrestrial Physics (SCOSTEP), Astronomical Society of India (ASI) and the Indian Space Research Organization (ISRO).


Solar Dynamo:

Smiley face    

The periodic variation of the Sun's large scale magnetic field is a well observed phenomenon. The complex interplay between the plasma flows and magnetic fields in the solar interior results in this periodic modulation of the global magnetic field activity of the Sun. The magnetohydrodynamic dynamo theory is able to provide better insight into the basic physical processes causing this variational nature of solar activity.

Dibyendu Nandi from IISER Kolkata along with his PhD students has been involved in developing numerical models to study the effects of plasma flows on the magnetic field deep within the solar convection zone. The adjacent figure (obtained from the developed dynamo model) depicts the plasma flow profile inside the solar convection zone.

Gravitational Waves:

Smiley face    

Gravitational waves are one of the several predictions of Einstein’s General Theory of Relativity. Just as Maxwell’s theory of electromagnetism leads to the conclusion that light is a wave, Einstein’s theory tells us that spacetime itself can show the same behavior. These ‘ripples’ in spacetime can give us new insights in understanding phenomena in the universe where gravity is extremely strong, like the collapse of massive stars, rapidly spinning black holes, and mergers of binary black holes and pulsars. With the detection of gravitational waves by LIGO, we have in our hands a new way of exploring the mysteries of the universe.

At CESSI, Rajesh Kumble Nayak works mainly on gravitational wave data analysis, where he uses statistical techniques to extract and analyze the signals detected by instruments like LIGO.


Smiley face    

Helioseismology is a tool to probe the solar interior using solar oscillations. These oscillations are due to seismic waves, generated by the turbulent convection of the solar interior. Information about the solar interior helps us to refine the existing theories of stellar structure and evolution developed using the global properties like radius, luminosity, mass, composition and age. It helps in studying the flows in the solar interior and hence gives better insight on solar magnetism.

In CESSI, our focus is on helioseismology of magnetic fields and large­scale flows in the solar interior. We mainly work on local helioseismology, which uses local propagation of waves to measure the properties of a relatively small area of the solar interior. We use techniques like time- distance seismology and ring diagram analysis for our work.


Smiley face    

CESSI, being committed towards the development of a scientific workforce in all areas of Space Sciences, puts significant effort into developing state-of-the-art instruments for both space and ground borne observatories. One of our current projects in instrumentation involves the development of a payload, the SUIT ( Solar UltraViolet Imaging Telescope ) on­board the Aditya-­L1 mission. Aditya­L1 is India's first venture towords studying the Sun with a satellite. Besides being an engineering marvel, it also boasts of being the first mission aimed at studying the chromosphere. Aditya has seven payloads in total – the primary being a coronograph (VELC), an imaging telescope (SUIT), accompanied by a magnetometer, two X-ray spectrometers (SoLEX and HEL1OS) and two particle detectors (ASPEX which includes the SWISS,STEPS­1 and PAPA). Aditya is scheduled for launch in 2019-­2020.

The SUIT payload is being developed under the leadership of Professor A N Ramaprakash (Instrument Principal Investigator and payload manager) and Professor Durgesh Tripathi (Principal Investigator) at IUCAA, Pune. Professor Dibyendu Nandi leads the science team of one of the science goals of the SUIT instrument. Current work on the instrument includes optical designing, component selection and performance modelling - on which CESSI personnel deployed at various national research centres are working. For more information on Aditya, visit - http://www.isro.gov.in/aditya-l1-first-indian-mission-to-study-sun.

Space Weather:

Smiley face    

The conditions of the immediate space surrounding Earth ( thermosphere, ionosphere, magnetosphere and the interplanetary space between Earth and Sun ) is modulated by the magnetic activity of the Sun. A space weather event is typically associated with the Sun ejecting huge amounts of magnetized plasma and energetic particles into space. Such events despite creating beautiful auroras, pose a threat to telecommunications systems, satellites and power grids among other undesirable effects.

We at CESSI direct our efforts towards both predicting and analysing the impact of space weather events through numerical simulations and multi-spacecraft observations. We use numerical models to study the large scale magnetic field of the Solar corona, the dynamics of which is thought to be the main driver of space weather events. Observations from numerous satellites are extensively used to constrain our theoretical models and conduct studies on the dependence of CME properties on their sources on the solar surface, the effect of CMEs on the thermosphere and ionosphere with the goal of assessing the pathways through which space weather effects are mediated.




The goal of the doctoral program is to train future generations of space scientists who are equipped with the necessary skills to lead national and international endeavours in the astrophysical space sciences. Students interested in pursuing research in space science and allied fields of interest to CESSI can apply for PhD positions. The cornerstone of the program lies in the collaboration that students are expected to develop with faculties associated with CESSI drawn from various Indian academic organizations. Scientists from reputed institutes within India and abroad visit CESSI year round to deliver lectures and explore research collaborations. CESSI cultivates an open academic atmosphere wherein students are encouraged to take advantage of the ensuing interactions to forge scientific collaborations across institutional borders. This cross-institutional exchange of knowledge is expected to leverage the available expertise within the country more effectively towards the advance training of PhD students.


Students are awarded a doctoral degree on successful completion of all degree requirements (including course-work) and the defense of their doctoral thesis. Nominally, the total PhD period is expected to be around 5 years. Students get a fellowship during the tenure of their PhD program which is determined based on Government norms.


Students with a competitive Masters degree (including MTech) from recognized academic organization are elligible to apply for the PhD program. The minimum eligibility criterion is available here. Note that students are expected to qualify at least one national level examination such as JEST, GATE, CSIR-UGC-NET. Students with INSPIRE fellowship are also encouraged to apply. Students may also apply based on any Government approved scheme for career advancement and mobility of Government personnel.

Selections are made after short-listed candidates appear for an interview. Shortlisting of candidates for the interview is based on the documents and other information submitted. The list of documents required shall be declared on the admission portal. Note that mere eligibility does not guarantee being short-listed which is based on several competitive criterion including the statement of interest and letters of recommendation. The final selection is based on the performance in the interview. CESSI selects only the best amongst the applicants who demonstrate strong aptitude and motivation for research in astrophysics and space sciences. When no suitable candidates of sufficient quality are found, no offers are made.

Important Dates

Advertisements for PhD are typically announced once a year on the CESSI web page, depending on the availability of vacancies. This is generally in between the months of February to April

Courses shall begin in the last week of July.


The program aims to attract highly motivated B.Tech and B.E. students with an engineering background who are desirous of contributing to fundamental research and mission-development in space sciences. The courses in this degree are aimed towards equipping students with the basic knowledge for tackling research problems in astrophysics. On completion of the degree the student would be well-placed to pursue a PhD program in any field of astrophysical space sciences.


In this two year program the first year involves both coursework and the performance of a research project. The final year is dedicated entirely to the MS Thesis research which typically is a continuation of the first year research project. For their MS Thesis research students can collaborate with a faculty from Department of Physical Sciences at IISER Kolkata or any affiliated CESSI faculty from other organizations.

The students are required to complete their course credit requirements and successfully defend their thesis to obtain the MS degree.


Students are expected to complete all the core courses and choose from a list of elective courses. Core courses typically include Introductory Astrophysics, Computational Physics, Space Astronomy and Fluid- and Magneto-Hydrodynamics or Gravitation and Cosmology. Electives include other courses that are on offer from CESSI and Department of Physical Sciences. The subjects taken by a student is usually chosen in consultation with the concerned student's research supervisor.


Students with a competitive 4-year Bachelor's degree in engineering will be considered provided strong background in Physics or Engineering is demonstrated. To consult minimum eligibility criterion please click here.

Like our PhD program, selections are only made after shortlisted candidates appear for an interview. Shortlisting of candidates for the interview is based on the documents and other information submitted. The list of documents required shall be declared in the admission portal. Note that satisfying the minimum eligibility criterion is no guarantee for short-listing, which is based on various other factors including statement of interest and recommendation letters. The final selection is based on performance in the interview.


The Masters program tenure is 2 years. Fellowship will be provided to all selected students.

Important Dates

Advertisement for the MS program is typically announced once a year (during March-April) depending on the availability of funding and seats. You are advised to check the website regularly after March.

Courses begin in the last week of July.



Ayan Banerjee

Collaborating Faculty
IISER Kolkata
ayan at iiserkol dot ac dot in

Dipankar Banerjee

Co-Investigator, IIA Bangalore
Indian Institute of Astrophysics
dipu at iiap.res.in

Nirmalya Ghosh

Collaborating Faculty
IISER Kolkata
nghosh at iiserkol dot ac dot in

Dibyendu Nandi

Principal Investigator and Head of the Centre
IISER Kolkata
dnandi at iiserkol dot ac dot in

Rajesh Kumble Nayak

IISER Kolkata
rajesh at iiserkol dot ac dot in

Paul Rajaguru

IIA Bangalore
rajaguru at iiap dot res dot in

A. N. Ramaprakash

Collaborating Faculty
anr at iucaa.in

K. Sankarasubramanian

ISRO Bangalore
sankark at isac dot gov dot in

Nandita Srivastava

USO-PRL Udaipur
nandita at prl dot res dot in

Prasad Subramanian

p.subramanian at iiserpune dot ac dot in

Durgesh Tripathi

Collaborating Faculty
durgesh at iucaa.in


Nabamita Das

Managerial Secretary
nabamita2606 at iiserkol dot ac dot in

Prosenjit Lahiri

System Administrator
prosenjit dot lahiri at iiserkol dot ac dot in


Arnab Basak

Postdoctoral Fellow
arnab dot pdf at iiserkol dot ac dot in

Rajashik Tarafder

Project Associate
rt12ms049 at iiserkol dot ac dot in


Lekshmi B

2015 Onwards
lb15rs016 at iiserkol dot ac dot in

Maitraya Kanta Bhattacharyya

2016 Onwards
mkb14ip002 at iiserkol dot ac dot in

Prantika Bhowmik

2013 Onwards
pb13rs014 at iiserkol dot ac dot in

Amar Deo Chandra

2015 Onwards
adc15rs019 at iiserkol dot ac dot in

Soumyaranjan Dash

2016 Onwards
sd16rs002 at iiserkol dot ac dot in

Avyarthana Ghosh

2013 Onwards
ag13rs013 at iiserkol dot ac dot in

Rakesh Mazumder

2013 Onwards
rm13rs027 at iiserkol dot ac dot in

Santanu Tripathy

2012 Onwards
st12rs048 at iiserkol dot ac dot in

Sanchita Pal

2015 Onwards
sp15rs036 at iiserkol dot ac dot in

Suvadip Sinha

2016 Onwards
ss16rs006 at iiserkol dot ac dot in

Athira B. S

2016 Onwards
abs14mr005 at iiserkol dot ac dot in

Anuradha Samajdar

2013 Onwards
anuradha1115 at iiserkol dot ac dot in

Sreejesh PS

2013 Onwards
sreejesh.peeyes at gmail dot com

Srijan B. Das

2013 Onwards
sbd13ms064 at iiserkol dot ac dot in

Suman Panda

2013 Onwards
sp13ms111 at iiserkol dot ac dot in

Manu Gupta

2017 Onwards
mg17mr003 at iiserkol dot ac dot in

Praveer Krishna Gollaudi

2017 Onwards
pkg17mr002 at iiserkol dot ac dot in

Unnati Ashar

2017 Onwards
una17mr001 at iiserkol dot ac dot in


Aveek Sarkar

Physical Research Laboratory
aveeks at gmail dot com

Sushant Mahajan

Doctoral Student
Georgia State University
mahajan at astro dot gsu dot edu

K.Chandrashekhar Reddy

Postdoctoral Researcher
Institute of Space Science, Shandong University
chandurie at gmail dot com

Abhinna kumar Behera

Doctoral Student
University of Reims
babhinnakumar at gmail dot com

Mayukh Panja

Doctoral Student
Max-Planck-Institut für Sonnensystemforschung
mayukhpanja at gmail.com

Tamoghna Majumdar

Graduated 2016
Center of Excellence in Space Sciences, India
tamz.msc1 at gmail dot com

Soumitra Hazra

Postdoctoral Research Associate
Georgia State University
soumitra dot hazra at gmail.com

Payel Mukhopadhyay

Doctoral Student
Stanford University
payelmukhopadhyay180 at gmail dot com

Anala K S

Graduated 2017
analasreekumar94 at gmail dot com

Madhusudan Ingale

Postdoctoral Fellow
Physical Research Laboratory
31mayur83 at gmail.com

Picture Gallery


Recent News

► LIGO Detects Gravitational Waves for the Third Time - Dr Rajesh Nayak and Ms Anuradha Samajdar PhD student, from the Center of Excellence in Space Sciences India (CESSI), are part of the IndIGO - LSC collaboration. They were actively involved in testing the Einstein's theory using gravitational waves in collaboration with Dr K. G. Arun (CMI-Chennai) and Dr Chandra K Mishra (IIT Madras) together with other members of LIGO collaboration. Hearty congratulations to Dr. Nayak and Ms. Samajdar.

Read More

Recent Events

► 19 April, 2017
CESSI Colloquia Series: Effect of Active Region Dynamics on Solar Flare Trigger
Speaker: Dr. Sreejith Padinhatteeri
Time: 12.00 PM
Venue: CESSI LAB, RC, IISER-K 24-26 March, 2017

► 24-26 March, 2017
Workshop: Space Astronomy and Telescope Making
Venue: Auditorium, RC, IISER Kolkata
Space Astronomy and Telescope Making Workshop

Read More


Public Lectures

CESSI organizes public lectures by eminent personalities from the field of science, technology and education to convey the excitement of scientific research and discovery to the public, with a focus on students. Past public lectures are highlighted here.

Astronomy and Space Science Outreach
CESSI organizes outreach activities targeting science students and school students with the focus being on astronomy and space sciences. Our outreach activities are highlighted here.

Promote Science Mission
Promote Science is a science outreach mission supported by CESSI which is run by research scholars of IISER Kolkata on a voluntary basis. The main goal of this mission is to enhance scientific awareness in our society and schools regarding career opportunities in diverse scientific disciplines.

CESSI Faculty Advisors for Outreach: Dibyendu Nandi, Rajesh Nayak
Managerial Assistance: Nabamita Das
CESSI Student Volunters: Lekshmi B., Maitraya Bhattacharyya, Amar Deo Chandra, Soumyaranjan Dash, Rajashik Tarafder, Suvadip Sinha

Contact: cessi@iiserkol.ac.in


Mohanpur - 741 246
West Bengal, India

+91 33 6634 0045



Contact Information

CESSI IISER-Kolkata Mohanpur - 741 246, West Bengal, India
+91 33 6634 0045
cessi at iiserkol.ac.in
CESSI Facebook


Register to our newsletter and be updated with the latest information regarding our activities and much more.

How to Reach