A Multiwavelength View of ρ Oph. II. Disentangling the Variability of the Multistar Component C
Year: 2026
Type: article
Abstract: We present a multiwavelength analysis of the star ρ Oph C, covering X-ray, optical, near-infrared (NIR), and radio observations to test for the presence of interferometrically detected cool star companions. The X-ray observations from Chandra, XMM-Newton, and NuSTAR show flare-like events lasting minutes or days in time and have spectral properties consistent with those of cooler stars instead of the primary magnetic B star. The NIR data are also consistent with the proposed trinary system properties due to the presence of CO bandheads. After removing the primary B star’s rotation, the optical data from TESS show a residual signal at the level of 0.8 mmag, matching the variations expected from cool stars in orbit around a bright B star. Finally, multiepoch radio data reveal that ρ Oph C exhibits significant large-scale flux variations that are atypical for a magnetic massive star. Taken as a whole, the multiepoch and -wavelength data present a consistent picture of ρ Oph C as a rare trinary system composed of a hot star and two cool stars.
Source: The Astrophysical Journal
Institutions: Massachusetts Institute of Technology, Center for Astrophysics Harvard & Smithsonian, Macalester College, Laboratório Nacional de Astrofísica, Space Telescope Science Institute, California State University, Fresno, University of Iowa, East Tennessee State University, Embry–Riddle Aeronautical University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Science Foundation, National Aeronautics and Space Administration, Michigan State University, Science and Industry Endowment Fund, Knox College, Macalester College, Augustana College, Space Telescope Science Institute, Australian Government, Commonwealth Scientific and Industrial Research Organisation, Ministério da Ciência, Tecnologia e Inovação, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Government of Western Australia, Centers for Disease Control and Prevention, College of Engineering, Michigan State University, University of North Carolina at Chapel Hill, Smithsonian Astrophysical Observatory
OpenAlex ID: W7214386361