How ELTs will acquire the first spectra of rocky habitable planets

Olivier Guyon, Frantz Martinache, Eric Cady, Ruslan Belikov, Balasubramanian Kunjithapatham, Daniel Wilson, Christophe Clergeon, Mala Mateen

Research output: Chapter in Book/Report/Conference proceedingConference contribution

18 Scopus citations


ELTs will offer angular resolution around 10mas in the near-IR and unprecedented sensitivity. While direct imaging of Earth-like exoplanets around Sun-like stars will stay out of reach of ELTs, we show that habitable planets around nearby M-type main sequence stars can be directly imaged. For about 300 nearby M dwarfs, the angular separation at maximum elongation is at or beyond 1 λ/D in the near-IR for an ELT. The planet to star contrast is 1e-7 to 1e-8, similar to what the upcoming generation of Extreme-AO systems will achieve on 8-m telescopes, and the potential planets are sufficiently bright for near-IR spectroscopy. We show that the technological solutions required to achieve this goal exist. For example, the PIAACMC coronagraph can deliver full starlight rejection, 100% throughput and sub-λ/D IWA for the EELT, GMT and TMT pupils. A closely related coronagraph is part of SCExAO on Subaru. We conclude that large ground-based telescopes will acquire the first high quality spectra of habitable planets orbiting M-type stars, while future space mission(s) will later target F-G-K type stars.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
Publication statusPublished - 2012
EventAdaptive Optics Systems III - Amsterdam, Netherlands
Duration: Jul 1 2012Jul 6 2012


OtherAdaptive Optics Systems III



  • Coronagraphy
  • Exoplanets
  • Extreme-AO

ASJC Scopus subject areas

  • Applied Mathematics
  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

Guyon, O., Martinache, F., Cady, E., Belikov, R., Kunjithapatham, B., Wilson, D., ... Mateen, M. (2012). How ELTs will acquire the first spectra of rocky habitable planets. In Proceedings of SPIE - The International Society for Optical Engineering (Vol. 8447). [84471X]