EChO: Exoplanet characterisation observatory

G. Tinetti, J. P. Beaulieu, T. Henning, M. Meyer, G. Micela, I. Ribas, D. Stam, M. Swain, O. Krause, M. Ollivier, E. Pace, B. Swinyard, A. Aylward, R. van Boekel, A. Coradini, T. Encrenaz, I. Snellen, M. R. Zapatero-Osorio, J. Bouwman, J. Y.K. ChoV. Coudé de Foresto, T. Guillot, M. Lopez-Morales, I. Mueller-Wodarg, E. Palle, F. Selsis, A. Sozzetti, P. A.R. Ade, N. Achilleos, A. Adriani, C. B. Agnor, C. Afonso, C. Allende Prieto, G. Bakos, R. J. Barber, M. Barlow, V. Batista, P. Bernath, B. Bézard, P. Bordé, L. R. Brown, A. Cassan, C. Cavarroc, A. Ciaravella, C. Cockell, A. Coustenis, C. Danielski, L. Decin, R. de Kok, O. Demangeon, P. Deroo, P. Doel, P. Drossart, L. N. Fletcher, M. Focardi, F. Forget, S. Fossey, P. Fouqué, J. Frith, M. Galand, P. Gaulme, J. I.González Hernández, O. Grasset, D. Grassi, J. L. Grenfell, M. J. Griffin, C. A. Griffith, U. Grözinger, M. Guedel, P. Guio, O. Hainaut, R. Hargreaves, P. H. Hauschildt, K. Heng, D. Heyrovsky, R. Hueso, P. Irwin, L. Kaltenegger, P. Kervella, D. Kipping, T. T. Koskinen, G. Kovács, A. La Barbera, H. Lammer, E. Lellouch, G. Leto, M. Lopez Morales, M. A. Lopez Valverde, M. Lopez-Puertas, C. Lovis, A. Maggio, J. P. Maillard, J. Maldonado Prado, J. B. Marquette, Javier Martin-Torres, P. Maxted, S. Miller, S. Molinari, D. Montes, A. Moro-Martin, J. I. Moses, O. Mousis, N. Nguyen Tuong, R. Nelson, G. S. Orton, E. Pantin, E. Pascale, S. Pezzuto, D. Pinfield, E. Poretti, R. Prinja, L. Prisinzano, J. M. Rees, A. Reiners, B. Samuel, A. Sánchez-Lavega, J. Sanz Forcada, D. Sasselov, G. Savini, B. Sicardy, A. Smith, L. Stixrude, G. Strazzulla, J. Tennyson, M. Tessenyi, G. Vasisht, S. Vinatier, S. Viti, I. Waldmann, G. J. White, T. Widemann, R. Wordsworth, R. Yelle, Y. Yung, S. N. Yurchenko

Research output: Contribution to journalArticle

105 Citations (Scopus)

Abstract

A dedicated mission to investigate exoplanetary atmospheres represents a major milestone in our quest to understand our place in the universe by placing our Solar System in context and by addressing the suitability of planets for the presence of life. EChO-the Exoplanet Characterisation Observatory-is a mission concept specifically geared for this purpose. EChO will provide simultaneous, multi-wavelength spectroscopic observations on a stable platform that will allow very long exposures. The use of passive cooling, few moving parts and well established technology gives a low-risk and potentially long-lived mission. EChO will build on observations by Hubble, Spitzer and ground-based telescopes, which discovered the first molecules and atoms in exoplanetary atmospheres. However, EChO's configuration and specifications are designed to study a number of systems in a consistent manner that will eliminate the ambiguities affecting prior observations. EChO will simultaneously observe a broad enough spectral region-from the visible to the mid-infrared-to constrain from one single spectrum the temperature structure of the atmosphere, the abundances of the major carbon and oxygen bearing species, the expected photochemically-produced species and magnetospheric signatures. The spectral range and resolution are tailored to separate bands belonging to up to 30 molecules and retrieve the composition and temperature structure of planetary atmospheres. The target list for EChO includes planets ranging from Jupiter-sized with equilibrium temperatures Teq up to 2,000 K, to those of a few Earth masses, with Teq \u223c 300 K. The list will include planets with no Solar System analog, such as the recently discovered planets GJ1214b, whose density lies between that of terrestrial and gaseous planets, or the rocky-iron planet 55 Cnc e, with day-side temperature close to 3,000 K. As the number of detected exoplanets is growing rapidly each year, and the mass and radius of those detected steadily decreases, the target list will be constantly adjusted to include the most interesting systems. We have baselined a dispersive spectrograph design covering continuously the 0. 4-16 μm spectral range in 6 channels (1 in the visible, 5 in the InfraRed), which allows the spectral resolution to be adapted from several tens to several hundreds, depending on the target brightness. The instrument will be mounted behind a 1. 5 m class telescope, passively cooled to 50 K, with the instrument structure and optics passively cooled to \u223c45 K. EChO will be placed in a grand halo orbit around L2. This orbit, in combination with an optimised thermal shield design, provides a highly stable thermal environment and a high degree of visibility of the sky to observe repeatedly several tens of targets over the year. Both the baseline and alternative designs have been evaluated and no critical items with Technology Readiness Level (TRL) less than 4-5 have been identified. We have also undertaken a first-order cost and development plan analysis and find that EChO is easily compatible with the ESA M-class mission framework.

Original languageEnglish
Pages (from-to)311-353
Number of pages43
JournalExperimental Astronomy
Volume34
Issue number2
DOIs
Publication statusPublished - Oct 1 2012
Externally publishedYes

Fingerprint

extrasolar planets
planets
observatories
planet
observatory
lists
atmospheres
solar system
atmosphere
temperature
telescopes
orbits
well technology
thermal environments
planetary atmosphere
planetary atmospheres
terrestrial planets
spectral resolution
European Space Agency
Jupiter (planet)

Keywords

  • Exoplanets
  • Planetary atmospheres
  • Space mission

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Tinetti, G., Beaulieu, J. P., Henning, T., Meyer, M., Micela, G., Ribas, I., ... Yurchenko, S. N. (2012). EChO: Exoplanet characterisation observatory. Experimental Astronomy, 34(2), 311-353. https://doi.org/10.1007/s10686-012-9303-4

EChO : Exoplanet characterisation observatory. / Tinetti, G.; Beaulieu, J. P.; Henning, T.; Meyer, M.; Micela, G.; Ribas, I.; Stam, D.; Swain, M.; Krause, O.; Ollivier, M.; Pace, E.; Swinyard, B.; Aylward, A.; van Boekel, R.; Coradini, A.; Encrenaz, T.; Snellen, I.; Zapatero-Osorio, M. R.; Bouwman, J.; Cho, J. Y.K.; de Foresto, V. Coudé; Guillot, T.; Lopez-Morales, M.; Mueller-Wodarg, I.; Palle, E.; Selsis, F.; Sozzetti, A.; Ade, P. A.R.; Achilleos, N.; Adriani, A.; Agnor, C. B.; Afonso, C.; Prieto, C. Allende; Bakos, G.; Barber, R. J.; Barlow, M.; Batista, V.; Bernath, P.; Bézard, B.; Bordé, P.; Brown, L. R.; Cassan, A.; Cavarroc, C.; Ciaravella, A.; Cockell, C.; Coustenis, A.; Danielski, C.; Decin, L.; de Kok, R.; Demangeon, O.; Deroo, P.; Doel, P.; Drossart, P.; Fletcher, L. N.; Focardi, M.; Forget, F.; Fossey, S.; Fouqué, P.; Frith, J.; Galand, M.; Gaulme, P.; Hernández, J. I.González; Grasset, O.; Grassi, D.; Grenfell, J. L.; Griffin, M. J.; Griffith, C. A.; Grözinger, U.; Guedel, M.; Guio, P.; Hainaut, O.; Hargreaves, R.; Hauschildt, P. H.; Heng, K.; Heyrovsky, D.; Hueso, R.; Irwin, P.; Kaltenegger, L.; Kervella, P.; Kipping, D.; Koskinen, T. T.; Kovács, G.; La Barbera, A.; Lammer, H.; Lellouch, E.; Leto, G.; Lopez Morales, M.; Lopez Valverde, M. A.; Lopez-Puertas, M.; Lovis, C.; Maggio, A.; Maillard, J. P.; Maldonado Prado, J.; Marquette, J. B.; Martin-Torres, Javier; Maxted, P.; Miller, S.; Molinari, S.; Montes, D.; Moro-Martin, A.; Moses, J. I.; Mousis, O.; Nguyen Tuong, N.; Nelson, R.; Orton, G. S.; Pantin, E.; Pascale, E.; Pezzuto, S.; Pinfield, D.; Poretti, E.; Prinja, R.; Prisinzano, L.; Rees, J. M.; Reiners, A.; Samuel, B.; Sánchez-Lavega, A.; Forcada, J. Sanz; Sasselov, D.; Savini, G.; Sicardy, B.; Smith, A.; Stixrude, L.; Strazzulla, G.; Tennyson, J.; Tessenyi, M.; Vasisht, G.; Vinatier, S.; Viti, S.; Waldmann, I.; White, G. J.; Widemann, T.; Wordsworth, R.; Yelle, R.; Yung, Y.; Yurchenko, S. N.

In: Experimental Astronomy, Vol. 34, No. 2, 01.10.2012, p. 311-353.

Research output: Contribution to journalArticle

Tinetti, G, Beaulieu, JP, Henning, T, Meyer, M, Micela, G, Ribas, I, Stam, D, Swain, M, Krause, O, Ollivier, M, Pace, E, Swinyard, B, Aylward, A, van Boekel, R, Coradini, A, Encrenaz, T, Snellen, I, Zapatero-Osorio, MR, Bouwman, J, Cho, JYK, de Foresto, VC, Guillot, T, Lopez-Morales, M, Mueller-Wodarg, I, Palle, E, Selsis, F, Sozzetti, A, Ade, PAR, Achilleos, N, Adriani, A, Agnor, CB, Afonso, C, Prieto, CA, Bakos, G, Barber, RJ, Barlow, M, Batista, V, Bernath, P, Bézard, B, Bordé, P, Brown, LR, Cassan, A, Cavarroc, C, Ciaravella, A, Cockell, C, Coustenis, A, Danielski, C, Decin, L, de Kok, R, Demangeon, O, Deroo, P, Doel, P, Drossart, P, Fletcher, LN, Focardi, M, Forget, F, Fossey, S, Fouqué, P, Frith, J, Galand, M, Gaulme, P, Hernández, JIG, Grasset, O, Grassi, D, Grenfell, JL, Griffin, MJ, Griffith, CA, Grözinger, U, Guedel, M, Guio, P, Hainaut, O, Hargreaves, R, Hauschildt, PH, Heng, K, Heyrovsky, D, Hueso, R, Irwin, P, Kaltenegger, L, Kervella, P, Kipping, D, Koskinen, TT, Kovács, G, La Barbera, A, Lammer, H, Lellouch, E, Leto, G, Lopez Morales, M, Lopez Valverde, MA, Lopez-Puertas, M, Lovis, C, Maggio, A, Maillard, JP, Maldonado Prado, J, Marquette, JB, Martin-Torres, J, Maxted, P, Miller, S, Molinari, S, Montes, D, Moro-Martin, A, Moses, JI, Mousis, O, Nguyen Tuong, N, Nelson, R, Orton, GS, Pantin, E, Pascale, E, Pezzuto, S, Pinfield, D, Poretti, E, Prinja, R, Prisinzano, L, Rees, JM, Reiners, A, Samuel, B, Sánchez-Lavega, A, Forcada, JS, Sasselov, D, Savini, G, Sicardy, B, Smith, A, Stixrude, L, Strazzulla, G, Tennyson, J, Tessenyi, M, Vasisht, G, Vinatier, S, Viti, S, Waldmann, I, White, GJ, Widemann, T, Wordsworth, R, Yelle, R, Yung, Y & Yurchenko, SN 2012, 'EChO: Exoplanet characterisation observatory', Experimental Astronomy, vol. 34, no. 2, pp. 311-353. https://doi.org/10.1007/s10686-012-9303-4
Tinetti G, Beaulieu JP, Henning T, Meyer M, Micela G, Ribas I et al. EChO: Exoplanet characterisation observatory. Experimental Astronomy. 2012 Oct 1;34(2):311-353. https://doi.org/10.1007/s10686-012-9303-4
Tinetti, G. ; Beaulieu, J. P. ; Henning, T. ; Meyer, M. ; Micela, G. ; Ribas, I. ; Stam, D. ; Swain, M. ; Krause, O. ; Ollivier, M. ; Pace, E. ; Swinyard, B. ; Aylward, A. ; van Boekel, R. ; Coradini, A. ; Encrenaz, T. ; Snellen, I. ; Zapatero-Osorio, M. R. ; Bouwman, J. ; Cho, J. Y.K. ; de Foresto, V. Coudé ; Guillot, T. ; Lopez-Morales, M. ; Mueller-Wodarg, I. ; Palle, E. ; Selsis, F. ; Sozzetti, A. ; Ade, P. A.R. ; Achilleos, N. ; Adriani, A. ; Agnor, C. B. ; Afonso, C. ; Prieto, C. Allende ; Bakos, G. ; Barber, R. J. ; Barlow, M. ; Batista, V. ; Bernath, P. ; Bézard, B. ; Bordé, P. ; Brown, L. R. ; Cassan, A. ; Cavarroc, C. ; Ciaravella, A. ; Cockell, C. ; Coustenis, A. ; Danielski, C. ; Decin, L. ; de Kok, R. ; Demangeon, O. ; Deroo, P. ; Doel, P. ; Drossart, P. ; Fletcher, L. N. ; Focardi, M. ; Forget, F. ; Fossey, S. ; Fouqué, P. ; Frith, J. ; Galand, M. ; Gaulme, P. ; Hernández, J. I.González ; Grasset, O. ; Grassi, D. ; Grenfell, J. L. ; Griffin, M. J. ; Griffith, C. A. ; Grözinger, U. ; Guedel, M. ; Guio, P. ; Hainaut, O. ; Hargreaves, R. ; Hauschildt, P. H. ; Heng, K. ; Heyrovsky, D. ; Hueso, R. ; Irwin, P. ; Kaltenegger, L. ; Kervella, P. ; Kipping, D. ; Koskinen, T. T. ; Kovács, G. ; La Barbera, A. ; Lammer, H. ; Lellouch, E. ; Leto, G. ; Lopez Morales, M. ; Lopez Valverde, M. A. ; Lopez-Puertas, M. ; Lovis, C. ; Maggio, A. ; Maillard, J. P. ; Maldonado Prado, J. ; Marquette, J. B. ; Martin-Torres, Javier ; Maxted, P. ; Miller, S. ; Molinari, S. ; Montes, D. ; Moro-Martin, A. ; Moses, J. I. ; Mousis, O. ; Nguyen Tuong, N. ; Nelson, R. ; Orton, G. S. ; Pantin, E. ; Pascale, E. ; Pezzuto, S. ; Pinfield, D. ; Poretti, E. ; Prinja, R. ; Prisinzano, L. ; Rees, J. M. ; Reiners, A. ; Samuel, B. ; Sánchez-Lavega, A. ; Forcada, J. Sanz ; Sasselov, D. ; Savini, G. ; Sicardy, B. ; Smith, A. ; Stixrude, L. ; Strazzulla, G. ; Tennyson, J. ; Tessenyi, M. ; Vasisht, G. ; Vinatier, S. ; Viti, S. ; Waldmann, I. ; White, G. J. ; Widemann, T. ; Wordsworth, R. ; Yelle, R. ; Yung, Y. ; Yurchenko, S. N. / EChO : Exoplanet characterisation observatory. In: Experimental Astronomy. 2012 ; Vol. 34, No. 2. pp. 311-353.
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title = "EChO: Exoplanet characterisation observatory",
abstract = "A dedicated mission to investigate exoplanetary atmospheres represents a major milestone in our quest to understand our place in the universe by placing our Solar System in context and by addressing the suitability of planets for the presence of life. EChO-the Exoplanet Characterisation Observatory-is a mission concept specifically geared for this purpose. EChO will provide simultaneous, multi-wavelength spectroscopic observations on a stable platform that will allow very long exposures. The use of passive cooling, few moving parts and well established technology gives a low-risk and potentially long-lived mission. EChO will build on observations by Hubble, Spitzer and ground-based telescopes, which discovered the first molecules and atoms in exoplanetary atmospheres. However, EChO's configuration and specifications are designed to study a number of systems in a consistent manner that will eliminate the ambiguities affecting prior observations. EChO will simultaneously observe a broad enough spectral region-from the visible to the mid-infrared-to constrain from one single spectrum the temperature structure of the atmosphere, the abundances of the major carbon and oxygen bearing species, the expected photochemically-produced species and magnetospheric signatures. The spectral range and resolution are tailored to separate bands belonging to up to 30 molecules and retrieve the composition and temperature structure of planetary atmospheres. The target list for EChO includes planets ranging from Jupiter-sized with equilibrium temperatures Teq up to 2,000 K, to those of a few Earth masses, with Teq \u223c 300 K. The list will include planets with no Solar System analog, such as the recently discovered planets GJ1214b, whose density lies between that of terrestrial and gaseous planets, or the rocky-iron planet 55 Cnc e, with day-side temperature close to 3,000 K. As the number of detected exoplanets is growing rapidly each year, and the mass and radius of those detected steadily decreases, the target list will be constantly adjusted to include the most interesting systems. We have baselined a dispersive spectrograph design covering continuously the 0. 4-16 μm spectral range in 6 channels (1 in the visible, 5 in the InfraRed), which allows the spectral resolution to be adapted from several tens to several hundreds, depending on the target brightness. The instrument will be mounted behind a 1. 5 m class telescope, passively cooled to 50 K, with the instrument structure and optics passively cooled to \u223c45 K. EChO will be placed in a grand halo orbit around L2. This orbit, in combination with an optimised thermal shield design, provides a highly stable thermal environment and a high degree of visibility of the sky to observe repeatedly several tens of targets over the year. Both the baseline and alternative designs have been evaluated and no critical items with Technology Readiness Level (TRL) less than 4-5 have been identified. We have also undertaken a first-order cost and development plan analysis and find that EChO is easily compatible with the ESA M-class mission framework.",
keywords = "Exoplanets, Planetary atmospheres, Space mission",
author = "G. Tinetti and Beaulieu, {J. P.} and T. Henning and M. Meyer and G. Micela and I. Ribas and D. Stam and M. Swain and O. Krause and M. Ollivier and E. Pace and B. Swinyard and A. Aylward and {van Boekel}, R. and A. Coradini and T. Encrenaz and I. Snellen and Zapatero-Osorio, {M. R.} and J. Bouwman and Cho, {J. Y.K.} and {de Foresto}, {V. Coud{\'e}} and T. Guillot and M. Lopez-Morales and I. Mueller-Wodarg and E. Palle and F. Selsis and A. Sozzetti and Ade, {P. A.R.} and N. Achilleos and A. Adriani and Agnor, {C. B.} and C. Afonso and Prieto, {C. Allende} and G. Bakos and Barber, {R. J.} and M. Barlow and V. Batista and P. Bernath and B. B{\'e}zard and P. Bord{\'e} and Brown, {L. R.} and A. Cassan and C. Cavarroc and A. Ciaravella and C. Cockell and A. Coustenis and C. Danielski and L. Decin and {de Kok}, R. and O. Demangeon and P. Deroo and P. Doel and P. Drossart and Fletcher, {L. N.} and M. Focardi and F. Forget and S. Fossey and P. Fouqu{\'e} and J. Frith and M. Galand and P. Gaulme and Hern{\'a}ndez, {J. I.Gonz{\'a}lez} and O. Grasset and D. Grassi and Grenfell, {J. L.} and Griffin, {M. J.} and Griffith, {C. A.} and U. Gr{\"o}zinger and M. Guedel and P. Guio and O. Hainaut and R. Hargreaves and Hauschildt, {P. H.} and K. Heng and D. Heyrovsky and R. Hueso and P. Irwin and L. Kaltenegger and P. Kervella and D. Kipping and Koskinen, {T. T.} and G. Kov{\'a}cs and {La Barbera}, A. and H. Lammer and E. Lellouch and G. Leto and {Lopez Morales}, M. and {Lopez Valverde}, {M. A.} and M. Lopez-Puertas and C. Lovis and A. Maggio and Maillard, {J. P.} and {Maldonado Prado}, J. and Marquette, {J. B.} and Javier Martin-Torres and P. Maxted and S. Miller and S. Molinari and D. Montes and A. Moro-Martin and Moses, {J. I.} and O. Mousis and {Nguyen Tuong}, N. and R. Nelson and Orton, {G. S.} and E. Pantin and E. Pascale and S. Pezzuto and D. Pinfield and E. Poretti and R. Prinja and L. Prisinzano and Rees, {J. M.} and A. Reiners and B. Samuel and A. S{\'a}nchez-Lavega and Forcada, {J. Sanz} and D. Sasselov and G. Savini and B. Sicardy and A. Smith and L. Stixrude and G. Strazzulla and J. Tennyson and M. Tessenyi and G. Vasisht and S. Vinatier and S. Viti and I. Waldmann and White, {G. J.} and T. Widemann and R. Wordsworth and R. Yelle and Y. Yung and Yurchenko, {S. N.}",
year = "2012",
month = "10",
day = "1",
doi = "10.1007/s10686-012-9303-4",
language = "English",
volume = "34",
pages = "311--353",
journal = "Experimental Astronomy",
issn = "0922-6435",
publisher = "Springer Netherlands",
number = "2",

}

TY - JOUR

T1 - EChO

T2 - Exoplanet characterisation observatory

AU - Tinetti, G.

AU - Beaulieu, J. P.

AU - Henning, T.

AU - Meyer, M.

AU - Micela, G.

AU - Ribas, I.

AU - Stam, D.

AU - Swain, M.

AU - Krause, O.

AU - Ollivier, M.

AU - Pace, E.

AU - Swinyard, B.

AU - Aylward, A.

AU - van Boekel, R.

AU - Coradini, A.

AU - Encrenaz, T.

AU - Snellen, I.

AU - Zapatero-Osorio, M. R.

AU - Bouwman, J.

AU - Cho, J. Y.K.

AU - de Foresto, V. Coudé

AU - Guillot, T.

AU - Lopez-Morales, M.

AU - Mueller-Wodarg, I.

AU - Palle, E.

AU - Selsis, F.

AU - Sozzetti, A.

AU - Ade, P. A.R.

AU - Achilleos, N.

AU - Adriani, A.

AU - Agnor, C. B.

AU - Afonso, C.

AU - Prieto, C. Allende

AU - Bakos, G.

AU - Barber, R. J.

AU - Barlow, M.

AU - Batista, V.

AU - Bernath, P.

AU - Bézard, B.

AU - Bordé, P.

AU - Brown, L. R.

AU - Cassan, A.

AU - Cavarroc, C.

AU - Ciaravella, A.

AU - Cockell, C.

AU - Coustenis, A.

AU - Danielski, C.

AU - Decin, L.

AU - de Kok, R.

AU - Demangeon, O.

AU - Deroo, P.

AU - Doel, P.

AU - Drossart, P.

AU - Fletcher, L. N.

AU - Focardi, M.

AU - Forget, F.

AU - Fossey, S.

AU - Fouqué, P.

AU - Frith, J.

AU - Galand, M.

AU - Gaulme, P.

AU - Hernández, J. I.González

AU - Grasset, O.

AU - Grassi, D.

AU - Grenfell, J. L.

AU - Griffin, M. J.

AU - Griffith, C. A.

AU - Grözinger, U.

AU - Guedel, M.

AU - Guio, P.

AU - Hainaut, O.

AU - Hargreaves, R.

AU - Hauschildt, P. H.

AU - Heng, K.

AU - Heyrovsky, D.

AU - Hueso, R.

AU - Irwin, P.

AU - Kaltenegger, L.

AU - Kervella, P.

AU - Kipping, D.

AU - Koskinen, T. T.

AU - Kovács, G.

AU - La Barbera, A.

AU - Lammer, H.

AU - Lellouch, E.

AU - Leto, G.

AU - Lopez Morales, M.

AU - Lopez Valverde, M. A.

AU - Lopez-Puertas, M.

AU - Lovis, C.

AU - Maggio, A.

AU - Maillard, J. P.

AU - Maldonado Prado, J.

AU - Marquette, J. B.

AU - Martin-Torres, Javier

AU - Maxted, P.

AU - Miller, S.

AU - Molinari, S.

AU - Montes, D.

AU - Moro-Martin, A.

AU - Moses, J. I.

AU - Mousis, O.

AU - Nguyen Tuong, N.

AU - Nelson, R.

AU - Orton, G. S.

AU - Pantin, E.

AU - Pascale, E.

AU - Pezzuto, S.

AU - Pinfield, D.

AU - Poretti, E.

AU - Prinja, R.

AU - Prisinzano, L.

AU - Rees, J. M.

AU - Reiners, A.

AU - Samuel, B.

AU - Sánchez-Lavega, A.

AU - Forcada, J. Sanz

AU - Sasselov, D.

AU - Savini, G.

AU - Sicardy, B.

AU - Smith, A.

AU - Stixrude, L.

AU - Strazzulla, G.

AU - Tennyson, J.

AU - Tessenyi, M.

AU - Vasisht, G.

AU - Vinatier, S.

AU - Viti, S.

AU - Waldmann, I.

AU - White, G. J.

AU - Widemann, T.

AU - Wordsworth, R.

AU - Yelle, R.

AU - Yung, Y.

AU - Yurchenko, S. N.

PY - 2012/10/1

Y1 - 2012/10/1

N2 - A dedicated mission to investigate exoplanetary atmospheres represents a major milestone in our quest to understand our place in the universe by placing our Solar System in context and by addressing the suitability of planets for the presence of life. EChO-the Exoplanet Characterisation Observatory-is a mission concept specifically geared for this purpose. EChO will provide simultaneous, multi-wavelength spectroscopic observations on a stable platform that will allow very long exposures. The use of passive cooling, few moving parts and well established technology gives a low-risk and potentially long-lived mission. EChO will build on observations by Hubble, Spitzer and ground-based telescopes, which discovered the first molecules and atoms in exoplanetary atmospheres. However, EChO's configuration and specifications are designed to study a number of systems in a consistent manner that will eliminate the ambiguities affecting prior observations. EChO will simultaneously observe a broad enough spectral region-from the visible to the mid-infrared-to constrain from one single spectrum the temperature structure of the atmosphere, the abundances of the major carbon and oxygen bearing species, the expected photochemically-produced species and magnetospheric signatures. The spectral range and resolution are tailored to separate bands belonging to up to 30 molecules and retrieve the composition and temperature structure of planetary atmospheres. The target list for EChO includes planets ranging from Jupiter-sized with equilibrium temperatures Teq up to 2,000 K, to those of a few Earth masses, with Teq \u223c 300 K. The list will include planets with no Solar System analog, such as the recently discovered planets GJ1214b, whose density lies between that of terrestrial and gaseous planets, or the rocky-iron planet 55 Cnc e, with day-side temperature close to 3,000 K. As the number of detected exoplanets is growing rapidly each year, and the mass and radius of those detected steadily decreases, the target list will be constantly adjusted to include the most interesting systems. We have baselined a dispersive spectrograph design covering continuously the 0. 4-16 μm spectral range in 6 channels (1 in the visible, 5 in the InfraRed), which allows the spectral resolution to be adapted from several tens to several hundreds, depending on the target brightness. The instrument will be mounted behind a 1. 5 m class telescope, passively cooled to 50 K, with the instrument structure and optics passively cooled to \u223c45 K. EChO will be placed in a grand halo orbit around L2. This orbit, in combination with an optimised thermal shield design, provides a highly stable thermal environment and a high degree of visibility of the sky to observe repeatedly several tens of targets over the year. Both the baseline and alternative designs have been evaluated and no critical items with Technology Readiness Level (TRL) less than 4-5 have been identified. We have also undertaken a first-order cost and development plan analysis and find that EChO is easily compatible with the ESA M-class mission framework.

AB - A dedicated mission to investigate exoplanetary atmospheres represents a major milestone in our quest to understand our place in the universe by placing our Solar System in context and by addressing the suitability of planets for the presence of life. EChO-the Exoplanet Characterisation Observatory-is a mission concept specifically geared for this purpose. EChO will provide simultaneous, multi-wavelength spectroscopic observations on a stable platform that will allow very long exposures. The use of passive cooling, few moving parts and well established technology gives a low-risk and potentially long-lived mission. EChO will build on observations by Hubble, Spitzer and ground-based telescopes, which discovered the first molecules and atoms in exoplanetary atmospheres. However, EChO's configuration and specifications are designed to study a number of systems in a consistent manner that will eliminate the ambiguities affecting prior observations. EChO will simultaneously observe a broad enough spectral region-from the visible to the mid-infrared-to constrain from one single spectrum the temperature structure of the atmosphere, the abundances of the major carbon and oxygen bearing species, the expected photochemically-produced species and magnetospheric signatures. The spectral range and resolution are tailored to separate bands belonging to up to 30 molecules and retrieve the composition and temperature structure of planetary atmospheres. The target list for EChO includes planets ranging from Jupiter-sized with equilibrium temperatures Teq up to 2,000 K, to those of a few Earth masses, with Teq \u223c 300 K. The list will include planets with no Solar System analog, such as the recently discovered planets GJ1214b, whose density lies between that of terrestrial and gaseous planets, or the rocky-iron planet 55 Cnc e, with day-side temperature close to 3,000 K. As the number of detected exoplanets is growing rapidly each year, and the mass and radius of those detected steadily decreases, the target list will be constantly adjusted to include the most interesting systems. We have baselined a dispersive spectrograph design covering continuously the 0. 4-16 μm spectral range in 6 channels (1 in the visible, 5 in the InfraRed), which allows the spectral resolution to be adapted from several tens to several hundreds, depending on the target brightness. The instrument will be mounted behind a 1. 5 m class telescope, passively cooled to 50 K, with the instrument structure and optics passively cooled to \u223c45 K. EChO will be placed in a grand halo orbit around L2. This orbit, in combination with an optimised thermal shield design, provides a highly stable thermal environment and a high degree of visibility of the sky to observe repeatedly several tens of targets over the year. Both the baseline and alternative designs have been evaluated and no critical items with Technology Readiness Level (TRL) less than 4-5 have been identified. We have also undertaken a first-order cost and development plan analysis and find that EChO is easily compatible with the ESA M-class mission framework.

KW - Exoplanets

KW - Planetary atmospheres

KW - Space mission

UR - http://www.scopus.com/inward/record.url?scp=84866897534&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84866897534&partnerID=8YFLogxK

U2 - 10.1007/s10686-012-9303-4

DO - 10.1007/s10686-012-9303-4

M3 - Article

AN - SCOPUS:84866897534

VL - 34

SP - 311

EP - 353

JO - Experimental Astronomy

JF - Experimental Astronomy

SN - 0922-6435

IS - 2

ER -