Our main research activity is currently focused on the commissioning and early science exploitation of the PLACID (Programmable Liquid-crystal Active Coronagraphic Imager for the DAG telescope) instrument. This includes not only instrumentation work, but also software development (data reduction pipeline, exposure time calculator etc.). The literature below outline the objectives, challenges, and preliminary results of the PLACID project along the way. One obvious key science objective of PLACID and RACE-GO is to look for circumbinary planets and disks, i.e. planets or circumstellar disks around binary (or triple) star systems, given that our instrument can mask as many host stars as needed.
SPIE Proceeding:
The Programmable Liquid-crystal Active Coronagraphic Imager for the DAG telescope (PLACID) instrument:
On-site status update ahead of first light
SPIE Proceeding:
Discovery space and science with the PLACID stellar coronagraph
SPIE Poster: Discovery space and science with the PLACID stellar coronagraph
This research effort explores the fundamentals of discrete pixelated phase coronagraphy, in particular by - but not limited to - using Spatial Light Modulators (SLMs) liquid-crystal display panels. The focus is on understanding the mechanics, applications, and advantages of this technology in high-contrast imaging systems, from numerical simulations to device characterization with interferometric metrology. We will also investigate alternative technologies to SLMs when implementing "adaptive coronagraphs", notably to improve optical throughput.
SPIE Proceeding: Future exoplanet direct imaging instruments: Simulating spatial light modulator-based pixelated focal-plane coronagraphy
Coherent Differential Imaging (CDI) relies on disentangling the temporally coherent signal from the host star (residual speckles, a frequent cause of "false positives" in our field) from bona-fide incoherent light from an off-axis astrophysical source of interest (planet, disk). This section explores the principles behind CDI, its implementation with a SLM, and its potential impact on direct imaging. This is one of the core goals of the ERC RACE-GO project. We will be able to validate the approach on-sky with PLACID at "slow speed" (30 Hz) before upgrading the instrument for high-speed millisecond CDI faster than the atmospheric turbulence.