Speckle Interferometry at SOAR in 2024 and 2025

Abstract

Abstract Results of speckle interferometry observations at the 4.1 m Southern Astrophysical Research telescope obtained during 2024–2025 are presented. We present 5316 measurements of relative positions and magnitude differences in 3532 pairs (including 524 unpublished measures made before 2024) with median and minimum separations of 0 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mrow> <mml:mi>.</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>″</mml:mi> </mml:mrow> </mml:mover> </mml:math> 19 and 12 mas, respectively; nonresolutions of 1723 stars are documented as well. More than 400 pairs have been resolved here for the first time and not resolved by Gaia; among those are 222 TESS objects of interest, 46 inner subsystems in known wider binaries within 100 pc, and 43 subdwarfs. Positional measurements are used to compute or improve binary orbits; elements of 202 orbits with meaningful errors are given here, while preliminary and tentative orbits are published elsewhere. Of special note are orbits with large and accurately measured eccentricities (e.g., e = 0.9866 ± 0.0014 for J13038−2035) and orbits of pre-main-sequence binaries. The Appendix contains parameters of 86 binaries used for calibration of pixel scale and orientation.

The authors' abstract, as published at the source. The Astronomical Journal, 2026 · DOI ↗