About
The success of NASA’s Kepler and TESS missions has revolutionized the discovery of planets beyond our Solar System. Studies of these extra-solar planets, or 'exoplanets', is now one of the fastest growing research areas in astronomy, and developing a detailed understanding of these distant worlds was highlighted as a key priority in the Pathways to Discovery Astro2020 Decadal Survey. Critical to enabling this research are ground-based extreme precision radial velocity (EPRV) spectrographs that measure the tiny changes in the color of light of distant stars caused by their motion due to planets orbiting around them. The orbiting planet's gravitational pull causes its parent star to "wobble," i.e. change its radial velocity (RV) in a periodic fashion, creating a tiny Doppler shift in the star's spectrum. This can be detected using a spectrograph: 'dark' spectral lines are seen to change color depending on the relative position of the planet and star as shown in the video below.
EPRV instrument must reach sub-meter-per-second radial velocity precisions to push the boundaries of planet detection, characterization, and mass determination. This allows the studies of other potentially habitable worlds and continues the search for life elsewhere in the universe. Achieving such precision however requires highly optimized instruments with exquisite calibration.
iLocater is one of these ultra-precise planet-finding spectrometers and is designed to enable advanced exoplanet studies. Operating with infrared wavelengths of light, iLocater is optimized to study exoplanets in orbit around stars smaller (and therefore cooler) than our own Sun. Currently under construction and testing, iLocater will be installed at the Large Binocular Telescope (LBT), AZ and will support key exoplanet and stellar observations. The instrument is one of the world's first diffraction-limited Doppler radial velocity instrument and uses the LBT AO system to inject light efficiently into single-mode optical fibers.
Instrument History/Timeline
- 2014 - iLocater approved for development as a 2nd generation instrument by LBT Board
- March/April 2016 - Fiber injection 'Demonstrator' tested on-sky at the LBT to characterize telescope environment for single-mode fiber coupling
- March 2017 - Acquisition camera passes preliminary design review (PDR)
- December 2017 - Spectrograph/cryostat pass preliminary design review (PDR)
- December 2018 - Acquisition camera passes final design review (FDR)
- February 2019 - Spectrograph passes fabrication readiness review
- June/July 2019 - SX (left) acquisition camera installed and commissioned on-sky at the LBT
- July 2020 - Cryostat vacuum chamber delivered to Notre Dame
- February 2023 - Cryostat system shipped to The Ohio State University for final integration and testing
- March 2023 - Spectrograph delivery from vendor