Cool Stars 14 - Submitted Abstract # 270
This version created on 05 October 2006

Radial Velocity Precision with the Triple Spec Spectrograph in the
Near-Infrared


Philip S. Muirhead, Cornell University
David J. Erskine, Lawrence Livermoore National Laboratory
Jerry Edelstein, University of California, Berkeley
Travis S. Barman, University of California, Los Angeles
James P. Lloyd, Cornell University

Infrared radial velocimetry of cool stars has been identified as a
likely method for detecting earth-sized planets in the near future.
The comparatively low mass and low variability of M and L stars give a
high Doppler-shift signal in the infrared due to stellar wiggle from
an orbiting planet.  For ground-based spectroscopy, the infrared part
of the spectrum is subject to changes in the amount of water vapor in
the Earth's atmosphere which can introduce Doppler-noise in addition
to the photon-limited Doppler-noise of the instrument.  Presented are
calculations of the photon-limited Doppler sensitivity of the
TripleSpec Externally Dispersed Interferometer (TEDI) near-infrared
instrument designed for the Palomar 200-inch Hale Telescope for a
series of low-mass stellar models.  Also, the effects of telluric
model uncertainty are considered for a particular stellar model.  This
spectrograph uses an interferometer before the dispersing element to
boost resolution and reject systematic noise.  Explanations of the
calculations, including interpreting the EDI signal, are given along
with the results.

----------------------------------