NOAO >   Observing Info >   Approved Programs >   2011A-0584

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Proposal Information for 2011A-0584


PI: Gregg Hallinan, UC Berkeley (Astronomy), gregg@astro.berkeley.edu
Address: Department of Astronomy, 601 Campbell Hall #3411, Berkeley, CA, 94720-3411, USA

CoI: Stuart Littlefair, University of Sheffield
CoI: Ray Butler, National University of Ireland
CoI: Gerry Doyle, Armagh Observatory
CoI: Michael Rupen, NRAO Arizona Facility
CoI: Leon Harding, National University of Ireland
CoI: Aaron Golden, National University of Ireland

Title: Confirming Auroral Emissions on an Ultracool Dwarf

Abstract: Ultracool dwarf pulsars are a small group of very low-mass stars and brown dwarfs (collectively: ultracool dwarfs) which show highly coherent radio emission which is pulsed on the rotational period. The radio emission is providing a new framework within which to interpret the magnetic properties of ultracool, one in which the magnetic fields and radio emission has more in common with the magnetospheres of giant planets, than Sun-like stars. The best studied of these objects is TVLM 513-46546. It shows periodic optical emission, and recent observations suggest that this variabilty may be a dramatic manifestation of aurorae on an ultracool dwarf. Here we request time-resolved spectroscopy of TVLM 513-46546 to measure the optical spectrum of the variable emission. These results will allow us to establish 1) the true spectrum of the auroral emission, 2) the temperature difference between the hot spot and the photosphere of the dwarf and 3) the amount of energy expended in producing this auroral hot spot.


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NOAO >   Observing Info >   Approved Programs >   2011A-0584

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