We report the detection of periodic ( p = 1.96 hours ) bursts of extremely bright , 100 % circularly polarized , coherent radio emission from the M9 dwarf TVLM 513-46546 .
Simultaneous photometric monitoring observations have established this periodicity to be the rotation period of the dwarf .
These bursts , which were not present in previous observations of this target , confirm that ultracool dwarfs can generate persistent levels of broadband , coherent radio emission , associated with the presence of kG magnetic fields in a large-scale , stable configuration .
Compact sources located at the magnetic polar regions produce highly beamed emission generated by the electron cyclotron maser instability , the same mechanism known to generate planetary coherent radio emission in our solar system .
The narrow beams of radiation pass our line of sight as the dwarf rotates , producing the associated periodic bursts .
The resulting radio light curves are analogous to the periodic light curves associated with pulsar radio emission highlighting TVLM 513-46546 as the prototype of a new class of transient radio source .