All-sky extrasolar planet searches with multi-object dispersed fixed-delay interferometer in optical and near IR

摘要

An all sky survey for extrasolar planets with wide field telescopes, Sloan 2.5m and WIYN 3.5 telescopes, is being developed. This survey will use a multi-object version of current Exoplanet Tracker (ET) Doppler instrument commissioned at the KPNO 2.1m telescope in June 2004. This instrument is based on dispersed fixed-delay interferometer, a combination of a Michelson interferometer with a moderate dispersion spectrometer (Ge 2002). This custom designed instrument (f/2 optics) has a wavelength coverage of ～ 600 A with a 4k * 4k CCD camera at a spectral resolution of R = 5,000. The measured instrument detection efficiency, including telescope, fiber, interferometer, spectrometer and detector losses, has ~ 18% (or 50% throughput from the fiber input to the detector), more than 4 times higher than current echelle instruments being used for planet detection. ET has been able to routinely obtain S/N ～ 80 data for V ～ 8 mag. stars in 15 min exposures with the KPNO 2.1m. It allows us to reach ～ 3.5 m/s Doppler precision for radial velocity (RV) stable stars with S/N ～ 120 per pixel. It also allows us to confirm an exoplanet curve of HD 130322 (V = 8.05) with rms Doppler error of 12.3 m/s (preliminary results). We are in the middle of design of two prototype multiple object RV instrument for the Sloan and WIYN telescopes, which are capable of observing 50 stars (V ～ 8-13) in a single exposure. We plan to conduct the all sky survey for planets around ～ 1 millions of stars with Sloan starting in 2008. Our goal is to identify ～ 100,000 extrasolar planets with ～ 1,000 solar analogues through this survey.