A New High Contrast Imaging Program at Palomar Observatory


Hinkley S. (1), Oppenheimer B. R. (2), Zimmerman N. (3,2), Vasisht G. (4), Parry I. R. (5), Soummer R. (6), Pueyo L. (7), Sivaramakrishnan A. (6), Brenner D. (2), Crepp J. (1), Hillenbrand L.(1), Beichman C. (4,8), Shao M. (4), Dekany R. (9), Roberts L. C. (4), Roberts J. (9), Bouchez A. (9)


(1) Caltech; (2) AMNH; (3) Columbia; (4) JPL; (5) IoA Cambridge; (6) STScI; (7) JHU; (8) NExScI; (9) COO


I will describe a new instrument that forms the core of a long-term high contrast imaging program at the 200-inch Hale Telescope at Palomar Observatory. The primary scientific thrust is to obtain imaging and low-resolution spectroscopy of brown dwarfs and young exoplanets of several Jupiter masses in the vicinity of stars within 25 pc. The instrument is a microlens-based integral field spectrograph integrated with a diffraction-limited, apodized-pupil Lyot coronagraph and mounted behind the Palomar AO system. The spectrograph obtains imaging in 23 channels across the J and H bands (1.05 - 1.75 microns). In addition to obtaining spectra, this wavelength resolution allows suppression of the chromatically dependent speckle noise, which we describe. In addition, we have recently installed a JPL-built, precision wave front calibration system internal to the coronagraph. The Palomar AO system is currently undergoing an upgrade to a much higher-order AO system (“PALM-3000”): a 3388-actuator tweeter deformable mirror working together with a 241-actuator mirror. This system will allow correction up to 8.1cm at the telescope pupil using natural guide stars. I will present measurements of our initial sensitivity, and show that spectral speckle suppression is providing a factor of 30 improvement over this. This system is part of a new generation of apodized pupil coronagraphs combined with high-order adaptive optics and integral field spectrographs (e.g. GPI, SPHERE, HiCIAO). We anticipate this instrument will make a lasting combination to high contrast imaging in the Northern Hemisphere for several years.

Attached documents

Lyot2010proc s7 poster HinkleyS.pdf
PDF, 9.2 Mb