BENGALURU: Isro on Monday announced the first Announcement of Opportunity (AO) cycle for its X-ray Polarimeter Satellite (XPoSat), inviting Indian scientists and researchers to submit proposals for observations using the space-based observatory.Launched on January 1, 2024, aboard the PSLV C-58 rocket from Sriharikota, XPoSat is India’s first dedicated X-ray polarimetry mission designed to study astronomical sources under extreme conditions. The satellite operates in a 650-kilometre near-equatorial orbit and carries two scientific payloads.“For this inaugural cycle, Isro is allocating 60% of the observatory’s time exclusively to Indian researchers for proposals using the XSPECT (X-ray Spectroscopy and Timing) payload, which captures spectroscopic and timing data in the 0.8-15 keV energy range. Observations are scheduled to run from Jan through Dec 2026,” the space agency said.This opens up significant opportunities for the Indian astronomy community to conduct cutting-edge research using world-class space infrastructure, as per Isro’s Science Programme Office.Eligible applicants include Indian scientists and researchers working at institutions, universities, and colleges across India who are involved in astronomy research. Principal investigators (PIs) must demonstrate the technical capability to analyse data if their proposals are approved.Researchers can submit proposals through the XPoSat Proposal Processing System (XPPS) at the Indian Space Science Data Centre (ISSDC) website. The deadline for submissions is Nov 30, 2025.Selected proposals will be reviewed by the XPoSat Time Allocation Committee (XTAC) for scientific merit and technical feasibility. Principal Investigators will receive a six-month proprietary period for their data, after which it will be made publicly available through ISSDC’s archive for the broader scientific community.Isro has made available comprehensive technical documentation, including the XSPECT User Handbook and proposal preparation tools like XPoViewer, which help researchers determine satellite visibility periods for their targets of interest.Scientists are expected to publish their findings in peer-reviewed journals with appropriate acknowledgment of XPoSat data usage.
