The JCMT Transient Survey: An Extraordinary Submillimeter Flare in the T Tauri Binary System JW 566

The binary T Tauri system JW 566 in the Orion Molecular Cloud underwent an energetic, short-lived flare observed at submillimeter wavelengths by the SCUBA-2 instrument on 2016 November 26 (UT). The emission faded by nearly 50% during the 31 minute integration. The simultaneous source fluxes averaged over the observation are 500 ± 107 mJy beam ^-1 at 450 μm and 466 ± 47 mJy beam ^-1 at 850 μm. The 850 μm flux corresponds to a radio luminosity of n L _ν = 8 × 10 ¹⁹ erg s ^-1 Hz ^-1 , approximately one order of magnitude brighter (in terms of νLν) than that of a flare of the young star GMR-A, detected in Orion in 2003 at 3mm. The event may be the most luminous known flare associated with a young stellar object and is also the first coronal flare discovered at submillimeter wavelengths. The spectral index between 450 and 850 μm of α = 0.11 is broadly consistent with nonthermal emission. The brightness temperature was in excess of 6 × 10 ⁴ K. We interpret this event to be a magnetic reconnection that energized charged particles to emit gyrosynchrotron/synchrotron radiation.