The 24 Aqr triple system: A closer look at its unique high-eccentricity hierarchical architecture
Ahmad Abushattal, Mashhoor A. Al-Wardat, Elliott P. Horch, Nikolaos Georgakarakos, Hatem A. Al-Ameryeen, Enas M. Abu-Alrob, Abdallah M. Hussein
TL;DR
This study provides a comprehensive reanalysis of the hierarchical triple system 24 Aqr by integrating new speckle interferometry data with three complementary methods: ORBITX-based dynamical modeling for the outer orbit, Edwards' method for disentangling the inner spectroscopic binary, and Al-Wardat's atmospheric modeling to generate synthetic SEDs and derive fundamental parameters. It yields refined masses for Aa, Ab, and B, a tightly constrained total mass, and a dynamical parallax close to Hipparcos and Gaia values, while also addressing the system's orbital alignment and coplanarity. The work demonstrates that resolving the inner binary visually would require a 65 m-class telescope or long-baseline interferometry, highlighting both the challenges and potential of high-angular-resolution studies of close hierarchical triples. By combining speckle data, spectroscopy, and synthetic photometry, the paper advances our understanding of the formation and evolution of hierarchical triples and provides precise benchmarks for stellar parameters and parallaxes in nearby systems.
Abstract
As its periastron passage occurred during the third quarter of 2020, system 24 Aqr is of particular significance. New visual solutions for the latest speckle interferometry observations collected by the Lowell Discovery Telescope (LTD) with its new QWSSI speckle camera are presented here. A variety of techniques were used to analyze the system, including ORBITX code for orbital solution, Al-Wardat's method for analyzing multiple stellar systems, and Edwards' method for analyzing visual and spectroscopic binaries. We derive precise masses and the complete set of its fundamental parameters for the three components, and we introduce a new orbital solution, and a new dynamical parallax, which is very close to the measured value given by Hipparcos 2007 and from that of Gaia DR2. In the next section, we discuss the possibility of a coplanar orbit. In conclusion, we demonstrate that we need a 65-m telescope to resolve the inner binary visually, although an array of telescopes could be used instead.