CV

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Contact Information

Name Koushik Sen
Professional Title Astrophysicist — massive binary evolution
Email ksen@arizona.edu
Location Steward Observatory, 933 N Cherry Ave, Tucson, Arizona AZ 85719
Website https://koushiksen1995.github.io

Professional Summary

Research on massive stars in binaries using detailed binary evolution models computed with MESA and multi-epoch spectroscopic and photometric observations from the NASA Hubble Space Telescope, NOIRLab Gemini Observatory and the ESO Very Large Telescope.

Experience

  • Jan 2025 - Present

    Tucson, AZ, USA

    Postdoctoral research associate
    Department of Astronomy, Steward Observatory, University of Arizona
  • Nov 2022 - Dec 2024

    Toruń, Poland

    Research Adjunct
    Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University

Education

  • Nov 2018 - Oct 2022

    Bonn, Germany

    PhD in Natural Sciences
    Argelander Institute for Astronomy, University of Bonn
    Astronomy and Astrophysics
    • Thesis: Evolution of short-period massive binaries in the Magellanic Clouds
    • Advisor: Prof. Dr. Norbert Langer
    • Awarded 27 September 2022; grade 1.3/4.0
  • 2018

    West Bengal, India

    Integrated Bachelors and Masters in Science
    Indian Institute of Technology Kharagpur
    Physics
    • Masters thesis: Modelling and evolution of supernova remnants
    • Advisor: Prof. Somnath Bharadwaj
    • GPA 9.65/10; Institute Silver Medalist
    • GRE General 332/340, GRE Physics 980/990 (December 2017)
  • 2013

    Kolkata, India

    High School (I.S.C.)
    Sri Aurobindo Institute of Education
    Mathematics, Physics, Chemistry, English
    • 95.25%; IIT JEE All India Rank 4958

Awards

  • 2025
    HST Cycle 33 research grant (PI)
    NASA / STScI, Prog. ID 18115

    43,676 USD

  • 2024
    IAU Travel Grant
    International Astronomical Union

    ~600 EUR, for the IAU General Assembly, Cape Town

  • 2022
    AG Travel Grant
    German Astronomical Society

    ~500 EUR

  • 2018
    Institute Silver Medal
    IIT Kharagpur

    Awarded on graduation

  • 2018
    Nilanjan Ganguly, Kedarnath Singh, H. N. Bose and G. B. Mitra Memorial Awards
    IIT Kharagpur

    Total ~20,000 INR

  • 2018
    APS Distinguished Student Program
    American Physical Society

    ~2,000 USD

  • 2017
    UARE Scholarship
    University of Alberta, Canada

    ~6,000 CAD

  • 2016
    DAAD WISE Scholarship
    German Academic Exchange Service

    ~2,000 EUR

  • 2013
    INSPIRE Fellow
    Department of Science and Technology, India

    ~300,000 INR over 2013–2018

  • 2013
    National Initiative on Undergraduate Sciences (NIUS) Fellow
    Homi Bhabha Centre for Science Education

    2013–2014

Awards won by my students

Competitive Telescope Time

  • 2026 · (PI) Gemini South / GHOST — Prop. Nr. 274432, 2026B, 40 hr
  • 2026 · (co-I) JWST / NIRCam + MIRI — Prop. Nr. 11424, Cycle 5, 7.4 hr
  • 2026 · (co-I) ESO VLT / X-SHOOTER — Prog. ID 117.2A9F, 7.25 hr
  • 2025 · (PI) HST / MAMA E140M — Prop. Nr. 18115, Cycle 33, 6 orbits
  • 2025 · (PI) XMM-Newton / EPIC pn — Prop. Nr. 096343, AO24, Priority C, 54 ks
  • 2025 · (co-I) ESO VLT / FEROS — Prog. ID 114.27SV, 92 hr
  • 2024 · (PI) ESO VLT / UVES — Prog. ID 114.27G8, 10 hr
  • 2024 · (co-I) ESO VLT / FEROS — Prog. ID 113.26Y5, 76 hr
  • 2023 · (co-I) ESO VLT / FLAMES — Prog. ID 112.25R7, 117 hr

Refereeing and Review Service

  • Hubble Space Telescope — Stellar Physics panellist, Cycles 33 and 34
  • ESO Very Large Telescope — distributed peer reviewer, P114
  • The Astrophysical Journal — 3 articles refereed
  • Astronomy & Astrophysics — 5 articles refereed
  • Publications of the Astronomical Society of the Pacific — Star Reviewer

Conference Organisation

  • 2026 · SOC, Binary Stars session, National Astronomy Meeting, University of Birmingham, UK (20–24 July 2026)

Workshops Attended

Invited Reviews

Invited Seminars

  • May 2026 · The Algol Renaissance — Astronomy Tea Talk, Caltech
  • Apr 2026 · X-ray emission from black hole binaries — KU Leuven, Belgium
  • May 2025 · X-ray emission from black holes in orbit with helium stars — FLASH Talk, NSF NOIRLab, Tucson
  • Oct 2023 · Massive Algols as whetstones for binary star evolution towards GW sources — IUCAA, Pune
  • Oct 2023 · Observable properties of massive interacting binaries on the main sequence — TIFR, Mumbai

Contributed Talks

  • Sep 2025 · Empirical constraints on mass transfer physics from massive Algol binaries — IAU Symposium 402, Ensenada, Mexico
  • Jun 2025 · Empirical constraints on mass transfer physics from massive Algol binaries — EAS 2025, Session S5, Cork, Ireland
  • Jun 2025 · X-ray emission from stripped helium star + black hole binaries — EAS 2025, Session SS37, Cork, Ireland
  • Sep 2024 · Whispering in the dark: X-ray faint BHs around OB stars — eROSITA Meeting, MPE Garching
  • Sep 2024 · Faint X-ray emission from black holes with OB star companions — VFTS Meeting, ESA Madrid
  • Aug 2024 · Whispering in the dark: X-ray faint BHs around OB stars — MODEST-24, Warsaw
  • Aug 2024 · Massive Algols as whetstones for the progenitors of gravitational wave sources — IAU Symposium 389, Cape Town (recording)
  • Jul 2024 · Observable properties of Algol binaries across the Hertzsprung-Russell diagram — LIAC41, Liège
  • Jul 2023 · Reverse Algols and hydrogen-rich Wolf-Rayet stars from massive binary evolution — EAS Annual Meeting, Kraków
  • Nov 2021 · Compact object progenitors and their companions on the HR diagram — SuperVirtual 2021
  • Nov 2021 · Detailed models of interacting short-period massive binary stars as progenitors of gravitational wave sources — MPA–NBIA Gravitational Wave Astrophysics Workshop, Garching
  • Apr 2018 · Variability in winds of magnetic massive stars: effect of unstable magnetosonic modes — APS April Meeting (abstract)

Public Outreach

Teaching Experience

  • 2025 · Guest Lecturer, graduate astronomy program, University of Arizona — X-ray emission from black holes (winter). Instructor: Brittany Miles. Slides
  • 2025 · Guest Lecturer, graduate astronomy program, University of Arizona — Massive binary star evolution (summer). Instructor: Mathieu Renzo. Slides, notes
  • 2024 · Guest Lecturer, Masters course, Nicolaus Copernicus University — Introduction to binary stars (summer). Instructor: Dorottya Szécsi
  • 2021 · Tutor, Masters course, University of Bonn — Stellar Nucleosynthesis (summer). Instructor: Norbert Langer
  • 2020 · Tutor, Masters course, University of Bonn — Stellar Structure and Evolution (winter). Instructor: Norbert Langer
  • 2020 · Tutor, Masters course, University of Bonn — Programming in Python (summer). Instructor: Thomas Erben

Undergraduate Research Experience

  • 2018 · Laser transmission through fibre at low (UV) wavelengths — Laser Spectroscopy Group, Max Planck Institute for Quantum Optics, Garching. Supervisor: Thomas Udem, in the group of T. W. Hänsch
  • 2017 · Short-term variability in magnetized massive stars: contribution from unstable magnetosonic waves — University of Alberta, Edmonton. Supervisor: Rodrigo Fernández. Published as Sen, Fernández & Socrates (2018)
  • 2016 · The cooling zones of shocks in the winds of massive stars — University Observatory Munich, LMU. Supervisor: Joachim Puls
  • 2015 · Encoding information in the phases of qubits — IISER Kolkata, Kalyani. Supervisor: Prasanta K. Panigrahi
  • 2014 · Chaotic oscillations of a current-carrying coil in a magnetic field — Saha Institute of Nuclear Physics, Kolkata. Supervisor: A. N. Sekar Iyengar

Projects

  • 2025 - Present
    Stable Mass Transfer Enthusiasts

    Collaboration hosted at the Flatiron Institute, Center for Computational Astrophysics.

  • 2024 - Present
    The BLOeM survey

    VLT spectroscopic monitoring of massive stars in the SMC. PIs: Tomer Shenar and Julia Bodensteiner.

Publications

References

  • Prof. Dr. Norbert Langer

    PhD supervisor, Argelander Institute for Astronomy, University of Bonn

  • Prof. Dr. Hugues Sana

    Collaborator, Institute of Astronomy, KU Leuven

  • Prof. Dr. Dorottya Szécsi

    Postdoc supervisor, Nicolaus Copernicus University in Toruń

  • Prof. Dr. Mathieu Renzo

    Postdoc supervisor, Steward Observatory, University of Arizona