Year: 2026
Type: article
Abstract: Context . The study of astronomical transients at high energies provides insights into some of the most extreme physical events in the universe; however, carrying out their detection and fast follow-up studies are limited by instrumental constraints. Search for Transient Object in New observations using Known Sources (STONKS) is a near-real-time transient detection system for XMM-Newton offering the capability to detect transients in XMM-Newton observations at fainter fluxes than can be achieved with wide survey instruments. Aims . We present the transients detected with the STONKS pipeline found in an XMM-Newton multi-year heritage survey of the Galactic plane to identify and classify highly variable X-ray sources that have recently been reported in this region. Methods . We examined the alerts created by the STONKS pipeline from over 200 XMM observations of the Galactic plane, screening for instrumental effects. The 78 alerts associated with 70 real astrophysical sources were then subjected to further temporal and spectral analysis. Results . From the 70 sources we identified, we were able to classify 32 with a high degree of confidence, including 7 X-ray binaries, 1 γ-Cas analogue, and 1 magnetar candidate. Of the 70 sources, 23 were detected for the first time in X-rays. Conclusions . This systematic analysis of publicly available data has shown the value and potential of STONKS in the application to XMM-Newton observations. It will enable the community to detect transient and highly variable sources at fainter fluxes than with any other X-ray transient detection systems.
Source: Astronomy and Astrophysics
Institutions: Institut de Recherche en Astrophysique et Planétologie, European Space Agency, European Space Astronomy Centre, University of Insubria, Brera Astronomical Observatory, Max Planck Institute for Extraterrestrial Physics, National Institute for Astrophysics, Inter-University Centre for Astronomy and Astrophysics, Columbia University, University of Illinois Urbana-Champaign
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
Funders: National Science Foundation, National Aeronautics and Space Administration, California Institute of Technology, European Space Agency, European Commission, Centre National d’Etudes Spatiales, Nuclear Safety and Security Commission, Istituto Nazionale di Astrofisica, Jet Propulsion Laboratory, University of California, Los Angeles, Horizon 2020, National Science Foundation Graduate Research Fellowship Program
OpenAlex ID: W7128600595