Caltech has a 40% share of the Keck 1 and Keck 2 10-meter telescopes. These are the largest optical/NIR telescopes in the world and in total the ExoLab team members typically receive a total allocation of 40-50 nights per year to do exoplanetary science observations. Our primary instruments are:
A high resolution (R ~ 55,000) spectrometer that can be used for stellar spectroscopy or precision radial velocity work. HIRES is one of just three spectrometers in the world capable of < 2 m/s Doppler precision. This high precision and our 15+ year observational baseline have allowed us to discover some of the least massive and longest-period planets known.
NIRC2 + Adaptive Optics
NIRC2 is a sensitive infrared camera at Keck that allows us to search for faint, red companions that might be crowding the vicinity of our host star. Adaptive optics is a technical procedure in which the primary mirror is activley deformed using a series of actuators to counterbalance the aberations of the incoming starlight effectively stopping their "twinkling." This allows us to obtain very high-resolution images of the close-in environments of our target stars. With these techniques we can search for close companions that under certain conditions could mimic the signal of a transiting planet.
The "Big Eye" atop Palomar Mountain provides us with additional opportunities to do world-class stellar spectroscopy and exoplanet follow-up observing. Following are several of the instruments and techniques key to finding and understanding exoplanets:
Project 1640 is a newly installed suite of instrumentation dedicated to the goal of obtaining images and spectra of exoplanets. This project is a northern hemisphere counterpart to the Gemini Planet Imager (GPI) and the SPHERE program at the Very Large Telescope, both of which will achieve first light in Chile in 2012-13. Project 1640 is a combination of a next generation Adaptive Optics system, a coronagraph to block out the bright starlight, and an imaging spectrograph.
A moderate resolution (R = 2700) near-infrared spectrograph covering 1.0 to 2.5 microns simultaneously. The resolution and wavelength coverage of TripleSpec is ideal for studying low-mass stars, whose spectra peak in the near-infrared and contain many molecular absorption features. We use TripleSpec to measure stellar properties of low-mass stars, including exoplanet hosts, as stellar parameters are critical for determining the planetary parameters for planets detected by the Doppler technique or the transit technique.
This wide-field NIR imager is mounted at the prime focus of the 200-inch and provides a wide field of view and stable platform for observing secondary eclipses of transiting exoplanets. When the planet passes behind its star, we can use WIRC to measure the decrement in flux, thereby measuring the planet's temperature.<
MINERVA will be an array of small-aperture robotic telescopes to be built atop Palomar Mountain outfitted for both photometry and high-resolution spectroscopy. It will be the first U.S. observatory dedicated to exoplanetary science capable of both precise radial velocimetry and transit studies. The multi-telescope concept will be implemented to either observe separate targets or a single target with a larger effective aperture. The flexibility of the observatory will maximize scientific potential and also provide ample opportunities for education and public outreach. The design and implementation of MINERVA will be carried out by postdoctoral and student researchers at Caltech.
Lock-in Amplified Externally Dispersed Interferometry (LAEDI) is an experiment to develop novel instrumentation capable of measuring ultra-precise radial velocities of stars (< 10 cm/s of systematic uncertainty). The instrument combines new technologies recently developed in the medical industry (optical coherence tomography), large-format zero-read-noise detectors, and externally dispersed interferometry to achieve high Doppler precision. The goal of the experiment is to recover the 30 cm/s, 5-minute-duration seismological oscillations in the Sun, first observed using optical resonance spectroscopy of a single Solar potassium line. With LAEDI we hope to recover the oscillations with broad-band light, paving the way for future instruments on large telescopes to study asteroseismology of stars and measure the mass of Earth-like planets found to transit their host stars. LAEDI was recently awarded a JPL DRDF grant to develop a prototype (PIs: Phil Muirhead and Gautam Vasisht, Co-Is John Johnson and Kent Wallace).
This is an automated laser guide star adaptive optics (AO) system, delivering diffraction-limited resolution observing in the visible and near-infrared (0.1"-0.25") for up to hundreds of targets per night on modest sized telescopes. Robo-AO enables the exploration of science parameter spaces such as large (10k+) targeted AO surveys, rapid AO imaging of transient events and long-term AO monitoring not feasible on large diameter telescopes.
The Kepler Mission, NASA Discovery mission #10, is specifically designed to survey our region of the Milky Way galaxy to discover hundreds of Earth-size and smaller planets in or near the habitable zone and determine the fraction of the hundreds of billions of stars in our galaxy that might have such planets.