REDWOODS: A hybrid wavefront sensor / science camera to demonstrate extreme exoplanet imaging at Lick observatory

Over 5000 exoplanets have been discovered to date, but only a handful of these exoplanets have been directly imaged. Direct imaging requires detecting the exoplanet’s light despite the glare of its host star, but the exoplanet is millions to billions of times fainter than than its host star. Exoplanets that have been directly imaged so far are large and bright like Jupiter.

Detecting Earth-like exoplanets that could have life on their surface is the next goal, but this requires instruments that are at least 100 times more sensitive. The investigators will test new technologies designed to bridge this gap. This testing will take place on the Shane Telescope at Lick Observatory in California.

In addition, the team will engage undergraduate summer students from underrepresented groups to work on this project, and they will develop educational programs with local high schools.

The main factor currently limiting exoplanet imaging instrument sensitivity is residual “speckle” noise, which limits exoplanetary signal detection in science images. Speckles originate from a combination of (1) errors left over after an adaptive optics (AO) system has made an initial correction of the atmospheric turbulence, and (2) imperfections in the optical surfaces from the telescope and instrument.

This program will implement a new pathfinder wavefront sensing technology at Lick Observatory on the Shane telescope’s AO system (ShaneAO) called the Fast Atmospheric Self-coherent camera Technique (FAST), designed to overcome this speckle noise limit. This project to implement FAST at ShaneAO is called Real-time Exoplanet Direct imager via Wavefront control Of Optical DefectS (REDWOODS).

REDWOODS is a focal plane wavefront sensor (WFS) and coronagraphic imager that will demonstrate the technology needed to enable new exoplanet imaging science on future 30m-class telescopes. REDWOODS will also enable a simultaneous Z-H band Pyramid WFS, demonstrating new capabilities of this WFS technology. This project will engage undergraduate summer students to work on REDWOODS, which will contribute to the Cal-Bridge Program, a program to increase PhDs amongst underrepresented groups within California’s public university systems.

The team will also develop the Santa Cruz Extreme AO Laboratory portable unit project (SEALpup)—a hands-on portable REDWOODS demo for education and public outreach.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.