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Paul Eccleston - One of the best experts on this subject based on the ideXlab platform.
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Ariel: Enabling planetary science across light-years
2021Co-Authors: Giovanna Tinetti, Paul Eccleston, Giusi Micela, Jérémy Leconte, Göran Pilbratt, Carole Haswell, Pierre-olivier Lagage, Theresa Lüftinger, Michel Min, Ludovic PuigAbstract:Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. The payload consists of an off-axis Cassegrain telescope (primary mirror 1100 mm x 730 mm ellipse) and two separate instruments (FGS and AIRS) covering simultaneously 0.5-7.8 micron spectral range. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. The payload module is passively cooled via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling via an active Ne JT cooler. The Ariel payload is developed by a consortium of more than 50 institutes from 16 ESA countries, which include the UK, France, Italy, Belgium, Poland, Spain, Austria, Denmark, Ireland, Portugal, Czech Republic, Hungary, the Netherlands, Sweden, Norway, Estonia, and a NASA contribution.
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the Ariel payload a technical overview
Space Telescopes and Instrumentation 2020: Optical Infrared and Millimeter Wave, 2020Co-Authors: Paul Eccleston, Kevin Middleton, Rachel Drummond, Georgia Bishop, Andrew Caldwell, Lucile Desjonqueres, Ian Tosh, Nick Cann, M Crook, Matthew HillsAbstract:The Atmospheric Remote-Sensing Infrared Exoplanet Large-survey, Ariel, has been selected to be the next (M4) medium class space mission in the ESA Cosmic Vision programme. From launch in 2028, and during the following 4 years of operation, Ariel will perform precise spectroscopy of the atmospheres of ~1000 known transiting exoplanets using its metre-class telescope. A three-band photometer and three spectrometers cover the 0.5 µm to 7.8 µm region of the electromagnetic spectrum. This paper gives an overview of the mission payload, including the telescope assembly, the FGS (Fine Guidance System) - which provides both pointing information to the spacecraft and scientific photometry and low-resolution spectrometer data, the Ariel InfraRed Spectrometer (AIRS), and other payload infrastructure such as the warm electronics, structures and cryogenic cooling systems.
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A chemical survey of exoplanets with Ariel
Experimental Astronomy, 2018Co-Authors: Giovanna Tinetti, Paul Eccleston, Giusi Micela, Marc Ollivier, Jérémy Leconte, Göran Pilbratt, Pierre Drossart, Paul Hartogh, A. Heske, Ludovic PuigAbstract:Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. Ariel was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. Ariel will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. Ariel will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. Ariel is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H_2O, CO_2, CH_4 NH_3, HCN, H_2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of Ariel performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential Ariel targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that Ariel – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.
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The Phase A study of the ESA M4 mission candidate Ariel
Experimental Astronomy, 2018Co-Authors: Ludovic Puig, Göran Pilbratt, Pierre Drossart, A. Heske, Isabel Escudero, Pierre-elie Crouzet, Bram Vogeleer, Kate Symonds, Ralf Kohley, Paul EcclestonAbstract:Ariel, the Atmospheric Remote sensing Infrared Exoplanet Large survey, is one of the three M-class mission candidates competing for the M4 launch slot within the Cosmic Vision science programme of the European Space Agency (ESA). As such, Ariel has been the subject of a Phase A study that involved European industry, research institutes and universities from ESA member states. This study is now completed and the M4 down-selection is expected to be concluded in November 2017. Ariel is a concept for a dedicated mission to measure the chemical composition and structure of hundreds of exoplanet atmospheres using the technique of transit spectroscopy. Ariel targets extend from gas giants (Jupiter or Neptune-like) to super-Earths in the very hot to warm zones of F to M-type host stars, opening up the way to large-scale, comparative planetology that would place our own Solar System in the context of other planetary systems in the Milky Way. A technical and programmatic review of the Ariel mission was performed between February and May 2017, with the objective of assessing the readiness of the mission to progress to the Phase B1 study. No critical issues were identified and the mission was deemed technically feasible within the M4 programmatic boundary conditions. In this paper we give an overview of the final mission concept for Ariel as of the end of the Phase A study, from scientific, technical and operational perspectives.
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an integrated payload design for the atmospheric remote-sensing infrared exoplanet large-survey (Ariel): results from phase A and forward look to phase B1
2018Co-Authors: Kevin F. Middleton, Giovanna Tinetti, Paul Eccleston, Giusi Micela, Paul Hartogh, Jean-philippe Beaulieu, Manuel Güdel, Michiel Min, Miroslaw Rataj, Tom RayAbstract:Ariel (the Atmospheric Remote-sensing Infrared Exoplanet Large-survey) has been selected by ESA as the next medium-class science mission (M4), expected to be launched in 2028. The mission will be devoted to observing spectroscopically in the infrared a large population of warm and hot transiting exoplanets (temperatures from 500 K to 3000 K) in our nearby Galactic neighborhood, opening a new discovery space in the field of extrasolar planets and enabling the understanding of the physics and chemistry of these far away worlds. Ariel was selected for implementation by ESA in March 2018 from three candidate missions that underwent parallel phase A studies. This paper gives an overview of the design at the end of phase A and discusses plans for its evolution during phase B1, in the run-up to mission adoption. Ariel is based on a 1 m class telescope feeding two instruments: a moderate resolution spectrometer covering the wavelengths from 1.95 to 7.8 microns; and a three-channel photometer (which also acts as a fine guidance sensor) with bands between 0.5 and 1.2 microns combined with a low resolution spectrometer covering 1.25 to 1.9 microns. During its 3.5 years of operation from an L2 orbit, Ariel will continuously observe exoplanets transiting their host star. This paper presents an overall view of the integrated design of the payload proposed for this mission. The design tightly integrates the various payload elements in order to allow the exacting photometric stability targets to be met, while providing simultaneous spectral and photometric data from the visible to the mid-infrared. We identify and discuss the key requirements and technical challenges for the payload and describe the trade-offs that were assessed during phase A, culminating in the baseline design for phase B1. We show how the design will be taken forward to produce a fully integrated and calibrated payload for Ariel that can be built within the mission and programmatic constraints and will meet the challenging scientific performance required for transit spectroscopy.
Giovanna Tinetti - One of the best experts on this subject based on the ideXlab platform.
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Ariel: Enabling planetary science across light-years
2021Co-Authors: Giovanna Tinetti, Paul Eccleston, Giusi Micela, Jérémy Leconte, Göran Pilbratt, Carole Haswell, Pierre-olivier Lagage, Theresa Lüftinger, Michel Min, Ludovic PuigAbstract:Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. The payload consists of an off-axis Cassegrain telescope (primary mirror 1100 mm x 730 mm ellipse) and two separate instruments (FGS and AIRS) covering simultaneously 0.5-7.8 micron spectral range. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. The payload module is passively cooled via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling via an active Ne JT cooler. The Ariel payload is developed by a consortium of more than 50 institutes from 16 ESA countries, which include the UK, France, Italy, Belgium, Poland, Spain, Austria, Denmark, Ireland, Portugal, Czech Republic, Hungary, the Netherlands, Sweden, Norway, Estonia, and a NASA contribution.
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alfnoor a retrieval simulation of the Ariel target list
arXiv: Earth and Planetary Astrophysics, 2020Co-Authors: Quentin Changeat, Enzo Pascale, Billy Edwards, Lorenzo V Mugnai, Ahmed Alrefaie, Ingo Waldmann, Giovanna TinettiAbstract:In this work, we present Alfnoor, a dedicated tool optimised for population studies of exoplanet atmospheres. Alfnoor combines the latest version of the retrieval algorithm TauREx 3, with the instrument noise simulator ArielRad and enables the simultaneous retrieval analysis of a large sample of exo-atmospheres. We applied this tool to the Ariel list of planetary candidates and focus on hydrogen dominated, cloudy atmospheres observed in transit with the Tier-2 mode (medium Ariel resolution). As a first experiment, we randomised the abundances - ranging from 10$^{-7}$ to 10$^{-2}$ - of the trace gases, which include H$_2$O, CH$_4$, CO, CO$_2$ and NH$_3$. This exercise allowed to estimate the detection limits for Ariel Tier-2 and Tier-3 modes when clouds are present. In a second experiment, we imposed an arbitrary trend between a chemical species and the effective temperature of the planet. A last experiment was run requiring molecular abundances being dictated by equilibrium chemistry at a certain temperature. Our results demonstrate the ability of Ariel Tier-2 and Tier-3 surveys to reveal trends between the chemistry and associated planetary parameters. Future work will focus on eclipse data, on atmospheres heavier than hydrogen and will be applied also to other observatories.
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an updated study of potential targets for Ariel
EPSC-DPS Joint Meeting 2019, 2019Co-Authors: Billy Edwards, Giovanna Tinetti, Enzo Pascale, Lorenzo V Mugnai, Subhajit SarkarAbstract:Ariel has been selected as ESA's M4 mission for launch in 2028 and is designed for the characterization of a large and diverse population of exoplanetary atmospheres to provide insights into planetary formation and evolution within our Galaxy. Here we present a study of Ariel's capability to observe currently known exoplanets and predicted Transiting Exoplanet Survey Satellite (TESS) discoveries. We use the Ariel radiometric model (ArielRad) to simulate the instrument performance and find that ~2000 of these planets have atmospheric signals which could be characterized by Ariel. This list of potential planets contains a diverse range of planetary and stellar parameters. From these we select an example mission reference sample (MRS), comprised of 1000 diverse planets to be completed within the primary mission life, which is consistent with previous studies. We also explore the mission capability to perform an in-depth survey into the atmospheres of smaller planets, which may be enriched or secondary. Earth-sized planets and super-Earths with atmospheres heavier than H/He will be more challenging to observe spectroscopically. However, by studying the time required to observe ~110 Earth-sized/super-Earths, we find that Ariel could have substantial capability for providing in-depth observations of smaller planets. Trade-offs between the number and type of planets observed will form a key part of the selection process and this list of planets will continually evolve with new exoplanet discoveries replacing predicted detections. The Ariel target list will be constantly updated and the MRS re-selected to ensure maximum diversity in the population of planets studied during the primary mission life.
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A chemical survey of exoplanets with Ariel
Experimental Astronomy, 2018Co-Authors: Giovanna Tinetti, Paul Eccleston, Giusi Micela, Marc Ollivier, Jérémy Leconte, Göran Pilbratt, Pierre Drossart, Paul Hartogh, A. Heske, Ludovic PuigAbstract:Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. Ariel was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. Ariel will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. Ariel will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. Ariel is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H_2O, CO_2, CH_4 NH_3, HCN, H_2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of Ariel performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential Ariel targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that Ariel – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.
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The Ariel mission reference sample
Experimental Astronomy, 2018Co-Authors: Tiziano Zingales, Giovanna Tinetti, Giusi Micela, Jérémy Leconte, Ignazio Pillitteri, Subhajit SarkarAbstract:The Ariel (Atmospheric Remote-sensing Exoplanet Large-survey) mission concept is one of the three M4 mission candidates selected by the European Space Agency (ESA) for a Phase A study, competing for a launch in 2026. Ariel has been designed to study the physical and chemical properties of a large and diverse sample of exoplanets and, through those, understand how planets form and evolve in our galaxy. Here we describe the assumptions made to estimate an optimal sample of exoplanets – including already known exoplanets and expected ones yet to be discovered – observable by Ariel and define a realistic mission scenario. To achieve the mission objectives, the sample should include gaseous and rocky planets with a range of temperatures around stars of different spectral type and metallicity. The current Ariel design enables the observation of ∼1000 planets, covering a broad range of planetary and stellar parameters, during its four year mission lifetime. This nominal list of planets is expected to evolve over the years depending on the new exoplanet discoveries.
M Focardi - One of the best experts on this subject based on the ideXlab platform.
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The Ariel Instrument Control Unit
Experimental Astronomy, 2021Co-Authors: M Focardi, A M Di Giorgio, L. Naponiello, V. Noce, G. Preti, A. Lorenzani, A. Tozzi, C. Del Vecchio, E. Galli, M FarinaAbstract:Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey mission (Tinetti 2019 ; Puig et al. 2018 ; Pascale et al. 2018 ), has been selected in March 2018 by ESA for the fourth medium-class mission (M4) launch opportunity of the Cosmic Vision Program, with an expected lift off in late 2028. It is the first mission dedicated to measuring the chemical composition and thermal structures of the atmospheres of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of our own Solar System. Its Payload (P/L) (Eccleston and Tinetti 2018 ; Eccleston et al. 2017 ; Middleton et al. 2019 ), has been designed to perform transit spectroscopy from space during primary and secondary planetary eclipses in order to achieve a large unbiased survey concerning the nature of exoplanets atmospheres and their interiors, to determine the key factors affecting the formation and evolution of planetary systems (Tinetti et al. 2017 , 2018 ). Ariel will observe hundreds of warm and hot transiting gas giants, Neptunes and super-Earths around a wide range of host star types, targeting planets hotter than ∼ $\sim $ 600 K to take advantage of their well-mixed atmospheres. It will exploit primary and secondary transit spectroscopy in the 1.10 to 7.80 μ m spectral range and broad-band photometry in the optical (0.50 - 0.80 μ m ) and Near IR (0.80 - 1.10 μ m ) . One of the two instruments of the Ariel Payload is the Fine Guidance System (FGS), including three photometric channels (two used for guiding as well as science) between 0.5-1.1 μ m plus a low resolution NIR spectrometer for 1.1-1.95 μ m range. Along with FGS an IR Spectrometer (AIRS) (Amiaux et al. 2017 ) is foreseen, providing low-resolution spectroscopy in two IR channels: C h a n n e l 0 ( C H _0) for the 1.95 − 3.90 μ m band and C h a n n e l 1 ( C H _1) for the 3.90 − 7.80 μ m range. Finally, an Active Cooler System (ACS) including a Ne Joule-Thomson cooler is adopted to provide active cooling capability to the AIRS detectors working at cryogenic temperatures. AIRS is located at the intermediate focal plane of the telescope and common optical system and it hosts two HgCdTe-based hybrid IR detectors and two cold front-end electronics (CFEE) for detectors control and readout. Each CFEE is driven by a Detector Control Unit (DCU) part of AIRS but hosted within and managed by the Instrument Control Unit (ICU) of the Payload (Focardi et al. 2018 ). ICU is a warm unit residing into the S/C Service Module (SVM) and it is based on a cold redundant configuration involving the Power Supply Unit (PSU) and the Commanding and Data Processing Unit (CDPU) boards; both DCUs are instead cross-strapped and can be managed by the nominal or the redundant (PSU+CDPU) chain. ICU is in charge of AIRS management, collecting scientific and housekeeping (HK) telemetries from the spectrometer and HK from the telescope (temperatures readings), the P/L Optical Bench (OB) and other Subsystems (SS), thanks to a warm slave unit (TCU, Telescope Control Unit) interfaced to the ICU. Science and HK telemetries are then forwarded to the S/C, for temporary storage, before sending them to Ground. Here we describe the status of the ICU design at the end of B1 Phase, prior to the Mission Adoption Review (MAR) by ESA, with some still open architectural choices to be addressed and finalised once selected the ICU industrial Prime contractor.
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the Ariel instrument control unit design for the m4 mission selection review of the esa s cosmic vision program
Experimental Astronomy, 2018Co-Authors: M Focardi, E Pace, M Farina, A M Di Giorgio, I Ribas, Gesa L Bote, J C Morales, Colome J Ferrer, Sierra C Roig, Jerome AmiauxAbstract:The Atmospheric Remote-sensing Infrared Exoplanet Large-survey mission (Ariel) (Tinetti et al. 2017) is one of the three present candidates for the ESA M4 (the fourth medium mission) launch opportunity. The proposed Payload (Eccleston et al. 2017; Morgante et al. 2017; Da Deppo et al. 2017) will perform a large unbiased spectroscopic survey from space concerning the nature of exoplanets atmospheres and their interiors to determine the key factors affecting the formation and evolution of planetary systems. Ariel will observe a large number (> 500) of warm and hot transiting gas giants, Neptunes and super-Earths around a wide range of host star types, targeting planets hotter than 600 K to take advantage of their well-mixed atmospheres. It will exploit primary and secondary transits spectroscopy in the 1.2 − 8μ m spectral range and broad-band photometry in the optical and Near IR (NIR). The main instrument of the Ariel Payload is the IR Spectrometer (AIRS) (Amiaux et al. 2017) providing low-resolution spectroscopy in two IR channels: C h a n n e l 0 (C H 0) for the 1.95 − 3.90μ m band and C h a n n e l 1 (C H 1) for the 3.90 − 7.80μ m range. It is located at the intermediate focal plane of the telescope (Da Deppo et al. 2016, 2017, 2017) and common optical system and it hosts two IR sensors and two cold front-end electronics (CFEE) for detectors readout, a well defined process calibrated for the selected target brightness and driven by the Payload’s Instrument Control Unit (ICU).
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design of the instrument and telescope control units integrated subsystem of the esa Ariel payload
Space Telescopes and Instrumentation 2018: Optical Infrared and Millimeter Wave, 2018Co-Authors: M Focardi, G Morgante, E Pace, M Farina, A M Di Giorgio, C Sierraroig, J Colome, I Ribas, Gesa L Bote, L TerenziAbstract:The Atmospheric Remote-sensing Infrared Exoplanets Large-survey (Ariel) 1 Mission has been recently selected by ESA as the fourth medium-class Mission (M4) in the framework of the Cosmic Vision Program. The goal of Ariel is to investigate, thanks to VIS photometry and IR spectroscopy, the atmospheres of several hundreds of planets orbiting nearby stars in order to address the fundamental questions on how planetary systems form and evolve. 2 During its four-years mission, Ariel will observe several hundreds of exoplanets ranging from Jupiter- and Neptune-size down to super-Earth and Earth-size with its 1 meter-class telescope. 3 The analysis of spectra and photometric data will allow to extract the chemical fingerprints of gases and condensates in the planets atmospheres, including the elemental composition for the most favorable targets. It will also enable the study of thermal and scattering properties of the atmosphere as the planet orbits around its parent star.
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an afocal telescope configuration for the esa Ariel mission
International Conference on Space Optics — ICSO 2016, 2017Co-Authors: Vania Da Deppo, Riccardo Claudi, Kevin Middleton, G Morgante, M Focardi, E Pace, G MicelaAbstract:Ariel (Atmospheric Remote-sensing Infrared Exoplanet Large-survey) is one of the three candidates for the next ESA medium-class science mission (M4) expected to be launched in 2026. This mission will be devoted to observing spectroscopically in the infrared (IR) a large population of known transiting planets in the neighborhood of the Solar System, opening a new discovery space in the field of extrasolar planets and enabling the understanding of the physics and chemistry of these far away worlds. Ariel is based on a 1-m class telescope ahead of two spectrometer channels covering the band 1.95 to 7.8 microns. In addition there are four photometric channels: two wide band, also used as fine guidance sensors, and two narrow band. During its 3.5 years of operations from L2 orbit, Ariel will continuously observe exoplanets transiting their host star. The Ariel optical design is conceived as a fore-module common afocal telescope that will feed the spectrometer and photometric channels. The telescope optical design is composed of an off-axis portion of a two-mirror classic Cassegrain coupled to a tertiary off-axis paraboloidal mirror. The telescope and optical bench operating temperatures, as well as those of some subsystems, will be monitored and fine tuned/stabilised mainly by means of a thermal control subsystem (TCU-Telescope Control Unit) working in closed-loop feedback and hosted by the main Payload electronics unit, the Instrument Control Unit (ICU). Another important function of the TCU will be to monitor the telescope and optical bench thermistors when the Payload decontamination heaters will be switched on (when operating the instrument in Decontamination Mode) during the Commissioning Phase and cyclically, if required. Then the thermistors data will be sent by the ICU to the On Board Computer by means of a proper formatted telemetry. The latter (OBC) will be in charge of switching on and off the decontamination heaters on the basis of the thermistors readout values.
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the Ariel esa mission on board metrology
IEEE International Workshop on Metrology for AeroSpace, 2017Co-Authors: Carles Sierraroig, Vania Da Deppo, Josep Colome Ferrer, M Focardi, G MorganteAbstract:This paper will describe the on-board metrology subsystems of the Ariel Mission, proposed in the framework of the ESA M4 call.
Giusi Micela - One of the best experts on this subject based on the ideXlab platform.
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Ariel: Enabling planetary science across light-years
2021Co-Authors: Giovanna Tinetti, Paul Eccleston, Giusi Micela, Jérémy Leconte, Göran Pilbratt, Carole Haswell, Pierre-olivier Lagage, Theresa Lüftinger, Michel Min, Ludovic PuigAbstract:Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. The payload consists of an off-axis Cassegrain telescope (primary mirror 1100 mm x 730 mm ellipse) and two separate instruments (FGS and AIRS) covering simultaneously 0.5-7.8 micron spectral range. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. The payload module is passively cooled via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling via an active Ne JT cooler. The Ariel payload is developed by a consortium of more than 50 institutes from 16 ESA countries, which include the UK, France, Italy, Belgium, Poland, Spain, Austria, Denmark, Ireland, Portugal, Czech Republic, Hungary, the Netherlands, Sweden, Norway, Estonia, and a NASA contribution.
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A chemical survey of exoplanets with Ariel
Experimental Astronomy, 2018Co-Authors: Giovanna Tinetti, Paul Eccleston, Giusi Micela, Marc Ollivier, Jérémy Leconte, Göran Pilbratt, Pierre Drossart, Paul Hartogh, A. Heske, Ludovic PuigAbstract:Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. Ariel was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. Ariel will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. Ariel will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. Ariel is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H_2O, CO_2, CH_4 NH_3, HCN, H_2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of Ariel performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential Ariel targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that Ariel – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.
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The Ariel mission reference sample
Experimental Astronomy, 2018Co-Authors: Tiziano Zingales, Giovanna Tinetti, Giusi Micela, Jérémy Leconte, Ignazio Pillitteri, Subhajit SarkarAbstract:The Ariel (Atmospheric Remote-sensing Exoplanet Large-survey) mission concept is one of the three M4 mission candidates selected by the European Space Agency (ESA) for a Phase A study, competing for a launch in 2026. Ariel has been designed to study the physical and chemical properties of a large and diverse sample of exoplanets and, through those, understand how planets form and evolve in our galaxy. Here we describe the assumptions made to estimate an optimal sample of exoplanets – including already known exoplanets and expected ones yet to be discovered – observable by Ariel and define a realistic mission scenario. To achieve the mission objectives, the sample should include gaseous and rocky planets with a range of temperatures around stars of different spectral type and metallicity. The current Ariel design enables the observation of ∼1000 planets, covering a broad range of planetary and stellar parameters, during its four year mission lifetime. This nominal list of planets is expected to evolve over the years depending on the new exoplanet discoveries.
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an integrated payload design for the atmospheric remote-sensing infrared exoplanet large-survey (Ariel): results from phase A and forward look to phase B1
2018Co-Authors: Kevin F. Middleton, Giovanna Tinetti, Paul Eccleston, Giusi Micela, Paul Hartogh, Jean-philippe Beaulieu, Manuel Güdel, Michiel Min, Miroslaw Rataj, Tom RayAbstract:Ariel (the Atmospheric Remote-sensing Infrared Exoplanet Large-survey) has been selected by ESA as the next medium-class science mission (M4), expected to be launched in 2028. The mission will be devoted to observing spectroscopically in the infrared a large population of warm and hot transiting exoplanets (temperatures from 500 K to 3000 K) in our nearby Galactic neighborhood, opening a new discovery space in the field of extrasolar planets and enabling the understanding of the physics and chemistry of these far away worlds. Ariel was selected for implementation by ESA in March 2018 from three candidate missions that underwent parallel phase A studies. This paper gives an overview of the design at the end of phase A and discusses plans for its evolution during phase B1, in the run-up to mission adoption. Ariel is based on a 1 m class telescope feeding two instruments: a moderate resolution spectrometer covering the wavelengths from 1.95 to 7.8 microns; and a three-channel photometer (which also acts as a fine guidance sensor) with bands between 0.5 and 1.2 microns combined with a low resolution spectrometer covering 1.25 to 1.9 microns. During its 3.5 years of operation from an L2 orbit, Ariel will continuously observe exoplanets transiting their host star. This paper presents an overall view of the integrated design of the payload proposed for this mission. The design tightly integrates the various payload elements in order to allow the exacting photometric stability targets to be met, while providing simultaneous spectral and photometric data from the visible to the mid-infrared. We identify and discuss the key requirements and technical challenges for the payload and describe the trade-offs that were assessed during phase A, culminating in the baseline design for phase B1. We show how the design will be taken forward to produce a fully integrated and calibrated payload for Ariel that can be built within the mission and programmatic constraints and will meet the challenging scientific performance required for transit spectroscopy.
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the Ariel mission reference sample
arXiv: Earth and Planetary Astrophysics, 2017Co-Authors: Tiziano Zingales, Giovanna Tinetti, Jérémy Leconte, Ignazio Pillitteri, Giusi MicelaAbstract:The Ariel (Atmospheric Remote-sensing Exoplanet Large-survey) mission concept is one of the three M4 mission candidates selected by the European Space Agency (ESA) for a Phase A study, competing for a launch in 2026. Ariel has been designed to study the physical and chemical properties of a large and diverse sample of exoplanets, and through those understand how planets form and evolve in our galaxy. Here we describe the assumptions made to estimate an optimal sample of exoplanets - including both the already known exoplanets and the "expected" ones yet to be discovered - observable by Ariel and define a realistic mission scenario. To achieve the mission objectives, the sample should include gaseous and rocky planets with a range of temperatures around stars of different spectral type and metallicity. The current Ariel design enables the observation of ~1000 planets, covering a broad range of planetary and stellar parameters, during its four year mission lifetime. This nominal list of planets is expected to evolve over the years depending on the new exoplanet discoveries.
Ludovic Puig - One of the best experts on this subject based on the ideXlab platform.
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Ariel: Enabling planetary science across light-years
2021Co-Authors: Giovanna Tinetti, Paul Eccleston, Giusi Micela, Jérémy Leconte, Göran Pilbratt, Carole Haswell, Pierre-olivier Lagage, Theresa Lüftinger, Michel Min, Ludovic PuigAbstract:Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. The payload consists of an off-axis Cassegrain telescope (primary mirror 1100 mm x 730 mm ellipse) and two separate instruments (FGS and AIRS) covering simultaneously 0.5-7.8 micron spectral range. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. The payload module is passively cooled via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling via an active Ne JT cooler. The Ariel payload is developed by a consortium of more than 50 institutes from 16 ESA countries, which include the UK, France, Italy, Belgium, Poland, Spain, Austria, Denmark, Ireland, Portugal, Czech Republic, Hungary, the Netherlands, Sweden, Norway, Estonia, and a NASA contribution.
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A chemical survey of exoplanets with Ariel
Experimental Astronomy, 2018Co-Authors: Giovanna Tinetti, Paul Eccleston, Giusi Micela, Marc Ollivier, Jérémy Leconte, Göran Pilbratt, Pierre Drossart, Paul Hartogh, A. Heske, Ludovic PuigAbstract:Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. Ariel was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. Ariel will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. Ariel will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. Ariel is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H_2O, CO_2, CH_4 NH_3, HCN, H_2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of Ariel performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential Ariel targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that Ariel – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.
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The Phase A study of the ESA M4 mission candidate Ariel
Experimental Astronomy, 2018Co-Authors: Ludovic Puig, Göran Pilbratt, Pierre Drossart, A. Heske, Isabel Escudero, Pierre-elie Crouzet, Bram Vogeleer, Kate Symonds, Ralf Kohley, Paul EcclestonAbstract:Ariel, the Atmospheric Remote sensing Infrared Exoplanet Large survey, is one of the three M-class mission candidates competing for the M4 launch slot within the Cosmic Vision science programme of the European Space Agency (ESA). As such, Ariel has been the subject of a Phase A study that involved European industry, research institutes and universities from ESA member states. This study is now completed and the M4 down-selection is expected to be concluded in November 2017. Ariel is a concept for a dedicated mission to measure the chemical composition and structure of hundreds of exoplanet atmospheres using the technique of transit spectroscopy. Ariel targets extend from gas giants (Jupiter or Neptune-like) to super-Earths in the very hot to warm zones of F to M-type host stars, opening up the way to large-scale, comparative planetology that would place our own Solar System in the context of other planetary systems in the Milky Way. A technical and programmatic review of the Ariel mission was performed between February and May 2017, with the objective of assessing the readiness of the mission to progress to the Phase B1 study. No critical issues were identified and the mission was deemed technically feasible within the M4 programmatic boundary conditions. In this paper we give an overview of the final mission concept for Ariel as of the end of the Phase A study, from scientific, technical and operational perspectives.
