GRB 230204B: GIT Discovery of a Fast Fading Afterglow Associated with an Energetic Gamma-Ray Burst from a Massive Star Progenitor
Abstract We present a comprehensive multiwavelength study of a bright gamma-ray burst GRB 230204B, analyzing both prompt and afterglow emissions. This GRB is highly energetic, with an isotropic equivalent energy emission of E iso ∼ 2.2 × 10 54 erg released during the prompt emission. The GROWTH-India Telescope discovered a bright afterglow ( m r = 15.55) that fades rapidly (∝ t −1.82 ). The prompt emission shows a strong thermal photospheric emission along with a nonthermal high-energy component. We explore the evolution of these components and find them to be consistent with the theoretical expectations of the fireball model. Afterglow modeling reveals an energetic jet ( E γ ≳ 10 52 erg) expanding into a wind-type medium viewed nearly on-axis, suggesting a massive star progenitor with strong winds. We also explore correlations between the prompt emission and afterglow that may help to place GRB 230204B within the broader context of the long GRB population.
Authors
- Sudhanshu Barway (ORCID: https://orcid.org/0000-0002-3927-5402)
- Suman Bala (ORCID: https://orcid.org/0000-0002-6657-9022)
- V. Bhalerao (ORCID: https://orcid.org/0000-0002-6112-7609)
- J. Sollerman (ORCID: https://orcid.org/0000-0003-1546-6615)
- Ankur Ghosh (ORCID: https://orcid.org/0000-0003-2265-0381)
- Vishwajeet Swain (ORCID: https://orcid.org/0000-0002-7942-8477)
- Mayank Kumar Goyal (ORCID: https://orcid.org/0000-0001-8966-496X)
- P. Chandra (ORCID: https://orcid.org/0000-0002-0844-6563)
- G. C. Anupama
- Josiah Purdum (ORCID: https://orcid.org/0000-0003-1227-3738)
- G. Waratkar (ORCID: https://orcid.org/0000-0003-3630-9440)
- J. S. Bloom (ORCID: https://orcid.org/0000-0002-7777-216X)
- Kuntal Misra (ORCID: https://orcid.org/0000-0003-1637-267X)
- Divita Saraogi (ORCID: https://orcid.org/0000-0001-6332-1723)
- Viraj Karambelkar (ORCID: https://orcid.org/0000-0003-2758-159X)
- Utkarsh Pathak (ORCID: https://orcid.org/0009-0002-7897-6110)
- Stefan J. van der Walt
- Tomás Ahumada (ORCID: https://orcid.org/0000-0002-2184-6430)
- Aswin Suresh (ORCID: https://orcid.org/0009-0005-8230-030X)
- Dimple Dimple (ORCID: https://orcid.org/0009-0002-9041-9587)
- M. M. Kasliwal (ORCID: https://orcid.org/0000-0002-5619-4938)
- Harsh Kumar (ORCID: https://orcid.org/0000-0001-9563-3668)
Institutions
- Northwestern University (US)
- California Institute of Technology (US)
- Universities Space Research Association (US)
- Berkeley College (US)
- Indian Institute of Astrophysics (IN)
- Stockholm University (SE)
- Indian Institute of Technology Bombay (IN)
- University of Johannesburg (ZA)
- National Radio Astronomy Observatory (US)
- Aryabhatta Research Institute of Observational Sciences (IN)
- Center for Astrophysics Harvard & Smithsonian (US)
- AlbaNova (SE)
- University of Birmingham (GB)
- University of California, Berkeley (US)
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2026-03-12
- DOI
- https://doi.org/10.3847/1538-4357/ae459f
- Primary Topic
- Gamma-ray bursts and supernovae
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- California Institute of Technology
- Northwestern University
- University of Warwick
- Tata Institute of Fundamental Research
- Department of Science and Technology, Ministry of Science and Technology, India
- Indo-US Science and Technology Forum
- Trinity College Dublin
- Weizmann Institute of Science
- Indian Institute of Technology Bombay
- Stockholms Universitet
- Deutsches Elektronen-Synchrotron
- Science and Engineering Research Board
- Institut National de Physique Nucléaire et de Physique des Particules