James P. Lloyd (Cornell University)

Exploring Low Mass Stars, Brown Dwarfs and Exoplanets with Adaptive Optics and Precision Radial Velocities - James P. Lloyd Colloquium

ATNF Marsfield Lecture Theatre

Abstract

I will describe recent work on high contrast imaging and radial velocities for the characterization of companions to low mass stars, M dwarfs. TEDI (TripleSpec - Exoplanet Discovery Instrument) is a dedicated instrument for near infrared radial velocity searches for planetary companions to low-mass stars with the goal of achieving meters per second radial velocity precision. Heretofore, such planet searches have been limited almost entirely to the optical band and to stars that are bright in this band. Consequently, knowledge about planetary companions to the populous but visibly-faint low mass stars is limited. Current radial velocity searches for planets around early M dwarfs with visible wavelength spectrometers have already yielded remarkable discoveries. The extension of this capability to longer wavelengths opens up new opportunities in numerous mid-late M dwarfs and even brown dwarfs. TEDI has been commissioned on the Palomar 200" telescope in December 2007, and is currently in a science verification phase. Ultimately, direct detection of exoplanets will require significant progress in the high contrast imaging. I will describe a novel experiment in adaptive optics aperture masking interferometry on the Palomar 200" that has been used to measure dynamical masses and luminosities of low luminosity objects. In near future, improvements in the adaptive optics aperture masking technique will enable the detection of proto-planets in nearby starforming regions and the direct detection of super-jupiters around nearby young stars.