Presentation #102.144 in the session Poster Session.
The Astro2020 Decadal Survey recommended a “future large IR/O/UV telescope optimized for observing habitable exoplanets and general astrophysics” to be ready by end of the decade and that mission “to search for biosignatures from a robust number of about ~25 habitable zone [exo]planets.” But how can 25 spectra be achieved? What is the potential SNR, spectral resolution and bandwidth of 25 spectra? Can a higher number of earth-sized exoplanets be spectrally characterized with diminished SNR, spectral resolution or bandwidth and what potential lies in an increased quality of SNR, spectral resolution and bandwidth? If a tiered approached is used, as suggested in the LUVOIR final report, to screen exoplanets in a single, 20% bandwidth sub-spectra band for water and then to follow up with broader, higher quality spectra on interesting planets, are those higher quality spectra achievable within reasonable integration times on only a subset of the ‘screened’ targets, and if so, which subset of targets? Does the 800-1000 nm sub-band offer the highest potential number of characterized planets, given the quantum efficiency fall-off of silicon detectors in this band, or would a different sub-band, such as 680-830 nm, which has a tighter inner working angle for coronagraphs as well as a deep oxygen line and a shallow water line, offer a higher potential number of exoplanets? Are there other ways to optimize the tiered ‘reconnaissance’ metric? We evaluate these questions for a 6-m exoplanet direct imaging mission, scaling HabEx and LUVOIR to 6m. We evaluate these various potential yield metrics for coronagraph-only, starshade-only, and hybrid coronagraph-starshade architectures.