| Full text | |
| Author(s): |
Ordonez-Toro, Jazmin
;
Dzib, Sergio A.
;
Loinard, Laurent
;
Ortiz-Leon, Gisela
;
Kounkel, Marina A.
;
Galli, Phillip A. B.
;
Masque, Josep M.
;
Dupuy, Trent J.
;
Quiroga-Nunez, Luis H.
;
Rodriguez, Luis F.
Total Authors: 10
|
| Document type: | Journal article |
| Source: | Monthly Notices of the Royal Astronomical Society; v. 538, n. 3, p. 5-pg., 2025-03-19. |
| Abstract | |
Oph-S1 is the most luminous and massive stellar member of the nearby Ophiuchus star-forming region. Previous Very Long Baseline Array (VLBA) observations have shown it to be an intermediate-mass binary system (similar to 5M(circle dot)) with an orbital period of about 21 months, but a paucity of radio detections of the secondary near periastron could potentially have affected the determination of its orbital parameters. Here, we present nine new VLBA observations of Oph-S1 focused on its periastron passage in early 2024. We detect the primary in all observations and the secondary at five epochs, including three within about a month of periastron passage. The updated orbit, determined by combining our new data with 35 previous observations, agrees well with previous calculations and yields masses of 4.115 +/- 0.039M(circle dot )and 0.814 +/- 0.006M(circle dot ) for the two stars in the system. (AU) | |
| FAPESP's process: | 20/12518-8 - Dynamics and evolution of Young Stellar Clusters (DYSC) |
| Grantee: | Phillip Andreas Brenner Galli |
| Support Opportunities: | Research Grants - Young Investigators Grants |