A Multiwavelength View of ρ Oph. II. Disentangling the Variability of the Multistar Component C
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.
Authors
- Walter W. Golay (ORCID: https://orcid.org/0000-0001-7946-1034)
- Pragati Pradhan (ORCID: https://orcid.org/0000-0002-1131-3059)
- Sean J. Gunderson (ORCID: https://orcid.org/0000-0003-2602-6703)
- Christiana Erba (ORCID: https://orcid.org/0000-0003-1299-8878)
- John M. Cannon (ORCID: https://orcid.org/0000-0002-1821-7019)
- Richard Ignace (ORCID: https://orcid.org/0000-0002-7204-5502)
- A. Moreno (ORCID: https://orcid.org/0009-0005-9304-0742)
- Felipe Navarete (ORCID: https://orcid.org/0000-0002-0284-0578)
- Jackson Codd (ORCID: https://orcid.org/0000-0002-3534-7691)
- David P. Huenemoerder (ORCID: https://orcid.org/0000-0002-3860-6230)
Institutions
- East Tennessee State University (US)
- University of Iowa (US)
- Space Telescope Science Institute (US)
- Center for Astrophysics Harvard & Smithsonian (US)
- Laboratório Nacional de Astrofísica (BR)
- Macalester College (US)
- Massachusetts Institute of Technology (US)
- California State University, Fresno (US)
- Embry–Riddle Aeronautical University (US)
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2026-10-28
- DOI
- https://doi.org/10.3847/1538-4357/aeac15
- Primary Topic
- Stellar, planetary, and galactic studies
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Conselho Nacional de Desenvolvimento Científico e Tecnológico