A LOFAR mini-survey for low-frequency radio emission from the nearest   brown dwarfs
  We have conducted a mini-survey for low-frequency radio emission from some of the closest brown dwarfs to the Sun with rapid rotation rates: SIMP J013656.5+093347, WISEPC J150649.97+702736.0, and WISEPA J174124.26+255319.5. We have placed robust 3-sigma upper limits on the flux density in the 111 - 169 MHz frequency range for these targets: WISE 1506: < 0.72 mJy; WISE 1741: < 0.87 mJy; SIMP 0136: < 0.66 mJy. At 8 hours of integration per target to achieve these limits, we find that systematic and detailed study of this class of object at LOFAR frequencies will require a substantial dedication of resources. 
Ben Burningham, M. Hardcastle, J. D. Nichols, S.L. Casewell, S.P.   Littlefair, C. Stark, M. R. Burleigh, S. Metchev, M. E. ...
astro-ph.SR astro-ph.EP