text: 47,78,1328643574867628033,992535707557269504,Dr. Aaron Labdon,"Our new paper is out today! We present the first J band interferometric observations of a YSO using the MIRC-X instrument @CHARAArray. Observing the infamous outbursting star FU Orionis and the surrounding accretion disk. <LINK> Using our tri-wavelength observations we derive the temperature gradient across the disk. We find evidence of direct boundary layer accretion onto the central star and viscous heating in the inner disk. (A thanks to Laws et al 2020 for the wonderful GPI image) <LINK> A big thanks to collaborators from @UoE_Astro, @michiganastro and @CHARAArray for making this work possible.",https://arxiv.org/abs/2011.07865,"Context. FU Orionis is the archetypal FUor star, a subclass of young stellar object (YSO) that undergo rapid brightening events, often gaining 4-6 magnitudes on timescales of days. This brightening is often associated with a massive increase in accretion; one of the most ubiquitous processes in astrophysics from planets and stars to super-massive black holes. We present multi-band interferometric observations of the FU Ori circumstellar environment, including the first J-band interferometric observations of a YSO. Aims. We investigate the morphology and temperature gradient of the inner-most regions of the accretion disk around FU Orionis. We aim to characterise the heating mechanisms of the disk and comment on potential outburst triggering processes. Methods. Recent upgrades to the MIRC-X instrument at the CHARA array allowed the first dual-band J and H observations of YSOs.Using baselines up to 331 m, we present high angular resolution data of a YSO covering the near-infrared bands J, H, and K. The unprecedented spectral range of the data allows us to apply temperature gradient models to the innermost regions of FU Ori. Results. We spatially resolve the innermost astronomical unit of the disk and determine the exponent of the temperature gradient of the inner disk to $T=r^{-0.74\pm0.02}$. This agrees with theoretical work that predicts $T = r^{-0.75}$ for actively accreting, steady state disks, a value only obtainable through viscous heating within the disk. We find a disk which extends down to the stellar surface at $0.015\pm0.007$ au where the temperature is found to be $5800\pm700$ K indicating boundary layer accretion. We find a disk inclined at $32\pm4^\circ$ with a minor-axis position angle of $34\pm11^\circ$. ","Viscous Heating and Boundary Layer Accretion in the Disk of Outbursting