SUPERSHARP – Segmented Unfolding Primary for Exoplanet Research via Spectroscopic High Angular Resolution Photography
Ian Parry, Didier Queloz, Grant Kennedy, Nikku Madhusudhan, Amaury Triaud, Nic Walton, Ranjan Vasudevan, Piotr Zulawski, Kevin Heng, Willy Benz, Christoph Mordasini, Nicolas Thomas, Daniele Piazza, Stephane Udry, Sascha Quanz, David Mouillet, Jean-Luc Beuzit, Ignas Snellen, Matt Kenworthy, Don Pollaco, Sasha Hinkley, Beth Biller, Sarah Rugheimer
(Submitted on 18 Jan 2018)
We propose to search for biosignatures in the spectra of reflected light from about 100 Earth-sized planets that are already known to be orbiting in their habitable zones (HZ). For a sample of G and K type hosts, most of these planets will be between 25 and 50 milli-arcsec (mas) from their host star and 1 billion to 10 billion times fainter. To separate the planet’s image from that of its host star at the wavelength (763nm) of the oxygen biosignature we need a telescope with an aperture of 16 metres. Furthermore, the intensity of the light from the host star at the position in the image of the exoplanet must be suppressed otherwise the exoplanet will be lost in the glare.
This presents huge technical challenges. The Earth’s atmosphere is turbulent which makes it impossible to achieve the required contrast from the ground at 763nm. The telescope therefore needs to be in space and to fit the telescope in the rocket fairing it must be a factor of 4 or more times smaller when folded than when operational. To obtain spectroscopy of the planet’s biosignature at 763nm we need to use an integral field spectrometer (IFS) with a field of view (FOV) of 1000 x 1000 milli-arcsec (mas) and a spectral resolution of 100. This is a device that simultaneously takes many pictures of the exoplanet each at a slightly different wavelength which are then recorded as a data cube with two spatial dimensions and one wavelength dimension. In every data cube wavelength slice, the background light from the host star at the location of the planet image must be minimised. This is achieved via a coronagraph which blocks the light from the host star and active/adaptive optics techniques which continuously maintain very high accuracy optical alignment to make the images as sharp as possible. These are the technical challenges to be addressed in a design study.
Comments: A proposal in response to the ESA New Science Ideas call. Sept 2016. 25 pages
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:1801.06111 [astro-ph.IM] (or arXiv:1801.06111v1 [astro-ph.IM] for this version)
Submission history
From: Ian Parry
[v1] Thu, 18 Jan 2018 16:26:16 GMT (1883kb)
https://arxiv.org/abs/1801.06111
