Multiband Imaging of the HD 36546 Debris Disk: A Refined View from SCExAO/CHARIS

We present the first multiwavelength (near-infrared; 1.1-2.4 μm) imaging of HD 36546's debris disk, using the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system coupled with the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS). As a 3-10 Myr old star, HD 36546 presents a rare opportunity to study a debris disk at very early stages. SCExAO/CHARIS imagery resolves the disk over angular separations of ρ ∼ 0.″25-1.″0 (projected separations of rproj ∼ 25-101 au) and enables the first spectrophotometric analysis of the disk. The disk's brightness appears symmetric between its eastern and western extents, and it exhibits slightly blue near-infrared colors on average (e.g., J-K = -0.4 0.1) - suggesting copious submicron-sized or highly porous grains. Through detailed modeling adopting a Hong scattering phase function (SPF), instead of the more common Henyey-Greenstein function, and using the differential evolution optimization algorithm, we provide an updated schematic of HD 36546's disk. The disk has a shallow radial dust density profile (α in ≈ 1.0 and α out ≈ -1.5), a fiducial radius of r 0 ≈ 82.7 au, an inclination of i ≈ 79. 1, and a position angle of PA ≈ 80. 1. Through spine tracing, we find a spine that is consistent with our modeling, but also with a "swept-back wing"geometry. Finally, we provide constraints on companions, including limiting a companion responsible for a marginal Hipparcos-Gaia acceleration to a projected separation of ≲0.″2 and to a minimum mass of ≲11 M Jup.