The TripleSpec - Exoplanet Discovery Instrument (TEDI) is a device to use interferometric spectroscopy for the radialvelocity
detection of extrasolar planets at infrared wavelengths (0.9 - 2.4 μm). The instrument is a hybrid of an
interferometer and a moderate resolution echelle spectrograph (TripleSpec, R=2,700,) at the Cassegrain focus of the
Palomar 200" telescope. We describe our experimental diagnostic program using laboratory sources and standard stars in
different optical configurations, along with performance analysis and results. We explain our instrumental upgrade
development to achieve a long-term performance that can utilize our demonstrated, < 10 m/s, short-term velocity
The TripleSpec Exoplanet Discovery Instrument (TEDI) is optimized to detect extrasolar planets orbiting midto-
late M dwarfs using the Doppler technique at infrared wavelengths. TEDI is the combination of a Michelson
interferometer and a moderate-resolution near-infrared spectrograph, TripleSpec, mounted on the Cassegrain
focus of the Palomar 200-inch Hale Telescope. Here we present results from observations of a radial velocity
standard star and a laboratory source over the past year. Our results indicate that focus effects within the
interferometer, combined with non-common-path errors between the ThAr calibration source and starlight, limit
our performance to several 100 m/s. An upgraded version of TEDI, TEDI 2.0, will eliminate this behavior by
mixing ThAr with starlight in a scrambled fiber before a redesigned interferometer with minimal focal effects.
The TEDI (TripleSpec - Exoplanet Discovery Instrument) is the first instrument dedicated to the near infrared radial
velocity search for planetary companions to low-mass stars. The TEDI uses Externally Dispersed Interferometry (EDI), a
combination of interferometry and multichannel dispersive spectroscopy. We have joined a white-light interferometer
with the Cornell TripleSpec (0.9 - 2.4 μm) spectrograph at the Palomar Observatory 200" telescope and begun an
experimental program to establish both the experimental and analytical techniques required for precision IR velocimetry
and the Doppler-search for planets orbiting low mass stars and brown dwarfs.
The TEDI (TripleSpec Exoplanet Discovery Instrument) will be the first instrument fielded specifically for finding low-mass
stellar companions. The instrument is a near infra-red interferometric spectrometer used as a radial velocimeter.
TEDI joins Externally Dispersed Interferometery (EDI) with an efficient, medium-resolution, near IR (0.9 - 2.4 micron)
echelle spectrometer, TripleSpec, at the Palomar 200 telescope. We describe the instrument and its radial velocimetry
demonstration program to observe cool stars.
The TEDI (TripleSpec Externally Dispersed Interferometry) is an interferometric spectrometer that will be used to explore the population of planets around the lowest mass stars. The instrument, to be deployed on the Palomar 200 Cassegrain mount, includes a stabilized Michelson interferometer combined with a medium resolution, broad band (0.8 - 2.4 micron) spectrograph, TripleSpec. We describe the instrument design and its application to Doppler velocimetry and high-resolution spectroscopy.
The Cosmic Hot interstellar Plasma Spectrometer (CHIPS), successfully launched on 2003 January 12, provides astronomers with an observatory dedicated to observation of the hot interstellar medium in the extreme ultraviolet. We describe here the otpical and photometric performance of the spectrograph based on calibrations of the individual components, end-to-end vacuum tests, and in-orbit observations of the Moon.
We describe the design and development of the CHIPS microchannel plate detector. The Cosmic Hot Interstellar Plasma Spectrometer will study the diffuse radiation of the interstellar medium in the extreme ultraviolet band pass of 90Å to 260Å. Astronomical fluxes are expected to be low, so high efficiency in the band pass, good out-of-band rejection, low intrinsic background, and minimal image non-linearities are crucial detector properties. The detector utilizes three 75mm diameter microchannel plates (MCPs) in an abutted Z stack configuration. A NaBr photocathode material deposited on the MCP top surface enhances the quantum detection efficiency. The charge pulses from the MCPs are centroided in two dimensions by a crossed-delayline (XDL) anode. A four panel thin-film filter array is affixed above the MCPs to reduce sensitivity to airglow and scattered radiation, composed of aluminum, polyimide/boron, and zirconium filter panes. The detector is housed in a flight vacuum chamber to preserve the hygroscopic photocathode, the pressure sensitive thin-film filters, and to permit application of high voltage during ground test.
We present a status report on CHIPS, the Cosmic Hot Interstellar Plasma Spectrometer. CHIPS is the first NASA University-Class Explorer (UNEX) project. CHIPS was selected in 1998 and is now scheduled for launch in December of 2002. The grazing incidence CHIPS spectrograph will survey the sky and record spectra of diffuse emission in the comparatively unexplored wavelength band between 90 and 260 Å. These data will provide important new constraints on the temperature, ionization state, and emission measure of hot plasma in the "local bubble" of the interstellar medium.