SPICES a small space coronagraph to characterize giant and telluric planets in reflected light

Abstract

Abstract. SPICES (Spectro-Polarimetric Imaging and Characterization of Exoplanetary Systems) was proposed in 2010 for a a five-year M-class mission in the context of ESA Cosmic Vision. Its purpose is to image and characterize long-period extrasolar planets located at several AUs (0.5-10 AU) from nearby stars (<25 pc) with masses ranging from a few Jupiter masses down to Super-Earths (∼2 Earth radii, ∼10M ⊕ ), possibly habitable. In addition, circumstellar disks as faint as a few times the zodiacal light in the Solar System can be studied. SPICES is based on a 1.5-m off-axis telescope and can perform spectropolarimetric measurements in the visible (450-900 nm) at a spectral resolution of about 40. This paper summarizes the top science program and the choices made to conceive the instrument. The performance is illustrated for a few emblematic cases.

Galactic planetary science

“…Direct imaging from space is the expected next step to be taken in space after transit. Space telescopes with various types of coronagraphs are being studied in the US, Europe and Japan (Clampin & Lyon, 2010;Cash & New Worlds Study Team, 2010;Kasdin et al, 2012;Guyon et al, 2013;Serabyn et al, 2013;Boccaletti et al, 2013;Enya et al, 2011). A mission for direct imaging, would be technically more challenging than a transit one and certainly more expensive -the telescope cannot be a light bucket, to start with.…”

Apodized Pupil Lyot Coronagraphs for Arbitrary Apertures. Iv. Reduced Inner Working Angle and Increased Robustness to Low-Order Aberrations

“…In the next decade, new high-contrast imaging instruments are envisioned to observe fainter companions down to old/light gaseous planets seen in reflected light and massive rocky planets: on the ground with Extremely Large Telescopes (ELTs) and dedicated instruments (e.g., E-ELT/PCS; Kasper et al 2013) or in space with missions such as WFIRST-AFTA (Spergel et al 2013), probe-scale missions (Trauger et al 2010;Guyon et al 2010c;Boccaletti et al 2013), or the post-JWST flagship project ATLAST (Postman et al 2012). In addition to exquisite wavefront sensing methods (e.g., Zernike wavefront sensors; Wallace et al 2011;N'Diaye et al 2013b) and control strategies (e.g., deformable mirrors based methods; Shaklan & Green 2006;Pueyo & Kasdin 2007;Pueyo et al 2009), these future instruments will rely on novel high-performance coronagraphs to offer broadband raw contrasts down to 10 −10 , enabling spectroscopy of these planetary companions.…”

“…Most of these systems have shown capabilities to reach contrasts below 10 −7 at IWA smaller than 4 λ 0 /D over a finite bandwidth Δλ, where λ 0 and D denote the central wavelength of the bandpass and the telescope diameter (Mawet et al 2012). Such a performance is made possible with unobstructed circular aperture telescopes, making these coronagraphs compelling options for probe-scale missions with 1.5 m off-axis telescopes (Trauger et al 2010;Guyon et al 2010c;Boccaletti et al 2013).…”

“…In the next decade, new high-contrast imaging instruments are envisioned to observe fainter companions down to old/light gaseous planets seen in reflected light and massive rocky planets: on the ground with Extremely Large Telescopes (ELTs) and dedicated instruments (e.g. E-ELT/PCS, Kasper et al 2013) or in space with missions such as WFIRST-AFTA (Spergel et al 2013), probe-scale missions (Trauger et al 2010;Guyon et al 2010c;Boccaletti et al 2013), or the post-JWST flagship project ATLAST (Postman et al 2012). In addition to exquisite wavefront sensing methods (e.g.…”