M. Tessenyi

Publications (6)6.02 Total impact

• Article: Photometric stability analysis of the Exoplanet Characterisation Observatory

  I. P. Waldmann, E. Pascale, B. Swinyard, G. Tinetti, A. Amaral-Rogers, L. Spencer, M. Tessenyi, M. Ollivier, V. Coudé du Foresto
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  ABSTRACT: Photometric stability is a key requirement for time-resolved spectroscopic observations of transiting extrasolar planets. In the context of the Exoplanet Characterisation Observatory (EChO) mission design, we here present and investigate means of translating spacecraft pointing instabilities as well as temperature fluctuation of its optical chain into an overall error budget of the exoplanetary spectrum to be retrieved. Given the instrument specifications as of date, we investigate the magnitudes of these photometric instabilities in the context of simulated observations of the exoplanet HD189733b secondary eclipse.
  02/2013;
• Conference Proceeding: An integrated payload design for the Exoplanet Characterisation Observatory (EChO)

  B. Swinyard, G. Tinetti, P. Eccleston, A. Adriani, J.P. Bealieu, A. Coustenis, T. Belenguer Davila, N. Bowles, I. Bryson, V. Coude du Foresto, [......], J.M. Reess, I. Ribas, A. Sozzetti, J. Tennyson, M. Tessenyi, M.R. Swain, B. Winter, I. Waldmann, G. Wright, M.R. Zapatero Osorio
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  ABSTRACT: The Exoplanet Characterisation Observatory (EChO) is a space mission dedicated to undertaking spectroscopy of transiting exoplanets over the widest wavelength range possible. It is based around a highly stable space platform with a 1.2 m class telescope. The mission is currently being studied by ESA in the context of a medium class mission within the Cosmic Vision programme for launch post 2020. The payload suite is required to provide simultaneous coverage from the visible to the mid-infrared and must be highly stable and effectively operate as a single instrument. In this paper we describe the integrated spectrometer payload design for EChO which will cover the 0.4 to 16 micron wavelength band. The instrumentation is subdivided into 5 channels (Visible/Near Infrared, Short Wave InfraRed, 2 x Mid Wave InfraRed; Long Wave InfraRed) with a common set of optics spectrally dividing the input beam via dichroics. We discuss the significant design issues for the payload and the detailed technical trade-offs that we are undertaking to produce a payload for EChO that can be built within the mission and programme constraints and yet which will meet the exacting scientific performance required to undertake transit spectroscopy.
  SPIE Proceedings of Space Telescopes and Instrumentation 2012: Optical, Infrared, and Millimeter Wave, Amsterdam; 07/2012
• Article: Characterizing the Atmospheres of Transiting Planets with a Dedicated Space Telescope

  M. Tessenyi, M. Ollivier, G. Tinetti, J. P. Beaulieu, V. Coudé du Foresto, T. Encrenaz, G. Micela, B. Swinyard, I. Ribas, A. Aylward, J. Tennyson, M. R. Swain, A. Sozzetti, G. Vasisht, and P. Deroo
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  ABSTRACT: Exoplanetary science is one of the fastest evolving fields of today's astronomical research, continuously yielding unexpected and surprising results. Ground-based planet-hunting surveys, together with dedicated space missions such as Kepler and CoRoT, are delivering an ever-increasing number of exoplanets, over 690, and ESA's Gaia mission will escalate the exoplanetary census into the several thousands. The next logical step is the characterization of these new worlds. What is their nature? Why are they as they are? Use of the Hubble Space Telescope and Spitzer Space Telescope to probe the atmospheres of transiting hot, gaseous exoplanets has opened perspectives unimaginable even just 10 years ago, demonstrating that it is indeed possible with current technology to address the ambitious goal of characterizing the atmospheres of these alien worlds. However, these successful measurements have also shown the difficulty of understanding the physics and chemistry of these exotic environments when having to rely on a limited number of observations performed on a handful of objects. To progress substantially in this field, a dedicated facility for exoplanet characterization, able to observe a statistically significant number of planets over time and a broad spectral range will be essential. Additionally, the instrument design (e.g., detector performances, photometric stability) will be tailored to optimize the extraction of the astrophysical signal. In this paper, we analyze the performance and tradeoffs of a 1.2/1.4 m space telescope for exoplanet transit spectroscopy from the visible to the mid-IR. We present the signal-to-noise ratio as a function of integration time and stellar magnitude/spectral type for the acquisition of spectra of planetary atmospheres for a variety of scenarios: hot, warm, and temperate planets orbiting stars ranging in spectral type from hot F- to cooler M-dwarfs. Our results include key examples of known planets (e.g., HD 189733b, GJ 436b, GJ 1214b, and Cancri 55 e) and simulations of plausible terrestrial and gaseous planets, with a variety of thermodynamical conditions. We conclude that even most challenging targets, such as super-Earths in the habitable zone of late-type stars, are within reach of an M-class, space-based spectroscopy mission.
  The Astrophysical Journal 01/2012; 746(1):45. · 6.02 Impact Factor
• Source

  Available from: David Montes

  Article: 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, [......], G. Vasisht, S. Vinatier, S. Viti, I. Waldmann, G. J. White, T Widemann, R. Wordsworth, R. Yelle, Y. Yung, S. N. Yurchenko
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  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. EChO will build on observations by Hubble, Spitzer and groundbased telescopes, which discovered the first molecules and atoms in exoplanetary atmospheres. EChO will simultaneously observe a broad enough spectral region -from the visible to the mid-IR- to constrain from one single spectrum the temperature structure of the atmosphere and the abundances of the major molecular species. The spectral range and resolution are tailored to separate bands belonging to up to 30 molecules to 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 2000 K, to those of a few Earth masses, with Teq ~300 K. We have baselined a dispersive spectrograph design covering continuously the 0.4-16 micron spectral range in 6 channels (1 in the VIS, 5 in the IR), 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 ~45 K. EChO will be placed in a grand halo orbit around L2. 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.
  12/2011;
• Source

  Available from: Giusi Micela

  Article: Characterising the Atmospheres of Transiting Planets with a Dedicated Space Telescope

  M. Tessenyi, M. Ollivier, G. Tinetti, J. P. Beaulieu, V. Coudé du Foresto, T. Encrenaz, G. Micela, B. Swinyard, I. Ribas, A. Aylward, J. Tennyson, M. R. Swain, A. Sozzetti, G. Vasisht, P. Deroo
  [show abstract] [hide abstract]
  ABSTRACT: Exoplanetary science is among the fastest evolving fields of today's astronomical research. Ground-based planet-hunting surveys alongside dedicated space missions (Kepler, CoRoT) are delivering an ever-increasing number of exoplanets, now numbering at ~690, with ESA's GAIA mission planned to bring this number into the thousands. The next logical step is the characterisation of these worlds: what is their nature? Why are they as they are? The use of the HST and Spitzer Space Telescope to probe the atmospheres of transiting hot, gaseous exoplanets has demonstrated that it is possible with current technology to address this ambitious goal. The measurements have also shown the difficulty of understanding the physics and chemistry of these environments when having to rely on a limited number of observations performed on a handful of objects. To progress substantially in this field, a dedicated facility for exoplanet characterization with an optimised instrument design (detector performance, photometric stability, etc.), able to observe through time and over a broad spectral range a statistically significant number of planets, will be essential. We analyse the performances of a 1.2/1.4m space telescope for exoplanet transit spectroscopy from the visible to the mid IR, and present the SNR ratio as function of integration time and stellar magnitude/spectral type for the acquisition of spectra of planetary atmospheres in a variety of scenarios: hot, warm, and temperate planets, orbiting stars ranging in spectral type from hot F to cool M dwarfs. We include key examples of known planets (e.g. HD 189733b, Cancri 55 e) and simulations of plausible terrestrial and gaseous planets, with a variety of thermodynamical conditions. We conclude that even most challenging targets, such as super-Earths in the habitable-zone of late-type stars, are within reach of a M-class, space-based spectroscopy mission.
  11/2011;
• Conference Proceeding: Characterising Super Earths With The EChO Spacemission Concept

  M Tessenyi, M Ollivier, G Tinetti, J ~P Beaulieu, V Coudé du Foresto, T Encrenaz, G Micela, B Swinyard, I Ribas, A Aylward, J Tennyson, M ~R Swain, A Sozzetti, G Vasisht, P Deroo
  AAS/Division for Extreme Solar Systems Abstracts; 09/2011