VARIABLE AND POLARIZED RADIO EMISSION FROM THE T6 BROWN DWARF WISEP J112254.73+255021.5

Route & Wolszczan recently detected five radio bursts from the T6. dwarf WISEP. J112254.73+255021.5 and used the timing of these events to propose that this object rotates with an ultra-short period of similar to 17.3. minutes. We conducted follow-up observations with the Very Large Array and Gemini-North but found no evidence for this periodicity. We do, however, observe variable, highly circularly polarized radio emission. Assuming that the radio emission of this T. dwarf is periodically variable on similar to hour timescales, like other radio-active ultracool dwarfs, we infer a likely period of 116. minutes. However, our observation lasted only 162. minutes and so more data are needed to test this hypothesis. The handedness of the circular polarization switches twice and there is no evidence for any unpolarized emission component, the first time such a phenomenology has been observed in radio studies of very low-mass stars and brown dwarfs. We suggest that the object's magnetic dipole axis may be highly misaligned relative to its rotation axis.