| In this presentation, I am excited to share our recent research and efforts to search for exo-satellites and companions of companions. I will present the motivation behind this work and demonstrate the techniques we have developed, applying them to my most recent study of the Eta Telescopii B object. Eta Telescopii (η Tel) is a ~24 Myr A0V star with an M7/8 brown dwarf companion (η Tel B) located 4.2” away. η Tel also hosts a debris disk, and η Tel B is notably bright in H-band observations from NACO and SPHERE, exhibiting a contrast of 1.5e-3 relative to the star. Over the past 20 years, we have conducted extensive follow-up observations of this system, focusing on astrometric monitoring and orbital characterization. Our research targets surrounding structures and potential sub-brown dwarf companions (such as companions of companions, exo-satellites, exomoons, or circumplanetary disks) using high-contrast imaging techniques coupled with advanced post-processing. These findings may provide new insights into formation processes. Beyond η Tel, we are exploring a broader sample of more than 21 other substellar objects with similar goals. I will also present our coronagraphic SPHERE data analysis for η Tel B and discuss the potential to detect exo-satellites in this system and others. Ultimately, I aim to provide the most detailed view of the η Tel system to date, highlighting our work to enhance observational techniques and apply them to a wider array of targets. |
