Evaluating the LUVOIR Coronagraph Sensitivity to Telescope Aberrations
Abstract
Direct imaging of exoplanets in their habitable zone is extremely challenging due to two main factors: the proximity of the planet to the parent star and the flux ratio between the planet and the parent star, usually on the order of 10^-10 in the visible. The LUVOIR space observatory concept uses a large, segmented primary mirror (8-15 meters in diameter) paired with a high-performance coronagraph to meet its scientific objectives. The Extreme Coronagraph for Living Planet Systems (ECLIPS) is the coronagraph instrument on the LUVOIR Surveyor mission concept. It is split into three channels: UV (200 to 400 nm), optical (400 nm to 850 nm), and NIR (850 nm to 2.0 microns), with each channel equipped with two deformable mirrors for wavefront control, a suite of coronagraph masks, a low-order/out-of-band wavefront sensor, and separate science imagers and spectrographs. The Apodized Pupil Lyot Coronagraph (APLC) is one of the mask technologies baselined to enable 10^-10 contrast observations in the habitable zones of nearby Sun-like stars. For the LUVOIR observatory architecture, the coronagraph performance depends on active wavefront sensing and control, as well as metrology subsystems to compensate for errors in segment alignment, secondary mirror alignment, and global low-order wavefront errors. Here we present the latest simulations of these effects for different working angle regions and discuss the achieved contrast for exoplanet detection and characterization under these circumstances. Finally, we show simulated observations using high-fidelity spatial and spectral input models of complete planetary systems generated with the Haystacks code framework, setting boundaries for tolerance of such errors.
- Publication:
-
American Astronomical Society Meeting Abstracts #233
- Pub Date:
- January 2019
- Bibcode:
- 2019AAS...23314806J