Observations of Magnetic Fields Surrounding LkH<i>α</i> 101 Taken by the BISTRO Survey with JCMT-POL-2

We report the first high spatial resolution measurement of magnetic fields surrounding LkH$\alpha$ 101, a part Auriga-California molecular cloud. The observations were taken with POL-2 polarimeter on James Clerk Maxwell Telescope within framework B-fields In Star-forming Region Observations (BISTRO) survey. Observed polarization thermal dust emission at 850 $\mu$m is found to be mostly associated red-shifted gas component field displays relatively complex morphology. Two variants Davis-Chandrasekhar-Fermi method, unsharp masking and structure function, are used calculate strength in plane sky, yielding similar result $B_{\rm POS}\sim 115$ $\mathrm{\mu}$G. mass-to-magnetic-flux ratio critical value units, $\lambda\sim0.3$, smallest among values obtained for other regions surveyed by POL-2. This implies that 101 region sub-critical strong enough prevent gravitational collapse. inferred $\delta B/B_0\sim 0.3$ large scale dominates turbulent one. variation fraction total intensity can fitted power-law an index $\alpha=0.82\pm0.03$, which lies range previously reported clouds. find decreases rapidly proximity only early B star (LkH$\alpha$ 101) region. tangling joint effect grain alignment rotational disruption radiative torques potential explaining such decreasing trend.