High-contrast imaging in the Hyades with snapshot LOCI

TL;DR

This study demonstrates that the LOCI algorithm effectively enhances high-contrast imaging in snapshot observations, enabling detection of faint substellar companions around Hyades stars with improved contrast ratios.

Contribution

The paper applies LOCI to short-exposure Keck images, achieving high contrast and discovering new brown dwarf and low-mass stellar companions in the Hyades cluster.

Findings

Achieved contrast of 10^{-2} at 0.01"

Detected new substellar companions in one-third of targets

Validated LOCI effectiveness on snapshot and wide binary imaging

Abstract

To image faint substellar companions obscured by the stellar halo and speckles, scattered light from the bright primary star must be removed in hardware or software. We apply the "locally-optimized combination of images" (LOCI) algorithm to 1-minute Keck Observatory snapshots of GKM dwarfs in the Hyades using source diversity to determine the most likely PSF. We obtain a mean contrast of 10^{-2} at 0.01", 10^{-4} at <1", and 10^{-5} at 5". New brown dwarf and low-mass stellar companions to Hyades primaries are found in a third of the 84 targeted systems. This campaign shows the efficacy of LOCI on snapshot imaging as well as on bright wide binaries with off-axis LOCI, reaching contrasts sufficient for imaging 625-Myr late-L/early-T dwarfs purely in post-processing.