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| ESA SP-1323: ESA's Report to the 39th COSPAR Meeting |
The 39th meeting of the Committee on Space Research (COSPAR) was held 14-22 July 2012 in Mysore, India.
This report to COSPAR on the scientific activities of the European Space Agency was written by members of the Directorate of Earth Observation, the Directorate of Human Spaceflight and Operations and the Directorate of Science and Robotic Exploration.
Contents:
- Foreword by Jean-Jacques Dordain, Director General, ESA
- Earth Observation
- Introduction
- The Living Planet Programme
- The Earth Explorer Missions
- ERS and Envisat
- Human Spaceflight and Operations
- Introduction
- Overview: Columbus and ISS Facilities
- Funding Europe's ISS Research: ELIPS
- Research on the ISS
- Ongoing Research Using Other Platforms
- Projects under Development
- Science and Robotic Exploration
- Introduction
- Missions in Operation
- Missions in the Post-Operations and Archiving Phases
- Projects under Development
- Missions under Study
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| Publication date: 30 Jun 2012 |
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| Transiting exoplanets from the CoRoT space mission - XVI. The hot Jupiter CoRoT-17b: a very old planet |
| We report the detection of a hot Jupiter-type exoplanet, named CoRoT-17b, detected by the CoRoT satellite. It has a mass of 2.43 ± 0.30MJup and a radius of 1.02 ± 0.07RJup, while its mean density is 2.82 ± 0.38 g/cm3. The orbital period is 3.768125 ± 0.000257 days and the orbit is circular. It orbits an old (10.7 ± 1.0 Gyrs) main-sequence star making it an intriguing object for planetary evolution studies. Its internal structure is not well constrained yet and it can be a pure H/He giant as well as it can contain ~320 earth masses of heavier elements. |
| Publication date: 14 Jun 2011 |
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| CoRoT Reveals a Magnetic Activity Cycle in a Sun-Like Star |
| The 11-year activity cycle of the Sun is a consequence of a dynamo process occurring beneath its surface. We analyzed photometric data obtained by the CoRoT space mission, showing solarlike oscillations in the star HD49933, for signatures of stellar magnetic activity. Asteroseismic measurements of global changes in the oscillation frequencies and mode amplitudes reveal a modulation of at least 120 days, with the minimum frequency shift corresponding to maximum amplitude as in the Sun. These observations are evidence of a stellar magnetic activity cycle taking place beneath the surface of HD49933 and provide constraints for stellar dynamo models under conditions different from those of the Sun. |
| Publication date: 27 Aug 2010 |
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| A transiting giant planet with a temperature between 250 K and 430 K |
| Of the over 400 known exoplanets, there are about 70 planets that transit their central star, a situation that permits the derivation of their basic parameters and facilitates investigations of their atmospheres. Some short-period planets, including the first terrestrial exoplanet (CoRoT-7b), have been discovered using a space mission designed to find smaller and more distant planets than can be seen from the ground. Here we report transit observations of CoRoT-9b, which orbits with a period of 95.274 days on a low eccentricity of 0.11 ± 0.04 around a solar-like star. Its periastron distance of 0.36 astronomical units is by far the largest of all transiting planets, yielding a 'temperate' photospheric temperature estimated to be between 250 and 430 K. Unlike previously known transiting planets, the present size of CoRoT-9b should not have been affected by tidal heat dissipation processes. Indeed, the planet is found to be well described by standard evolution models with an inferred interior composition consistent with that of Jupiter and Saturn. |
| Publication date: 18 Mar 2010 |
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| Deviations from a uniform period spacing of gravity modes in a massive star |
| The life of a star is dominantly determined by the physical processes in the stellar interior. Unfortunately, we still have a poor understanding of how the stellar gas mixes near the stellar core, preventing precise predictions of stellar evolution. The unknown nature of the mixing processes as well as the extent of the central mixed region is particularly problematic for massive stars. Oscillations in stars with masses a few times that of the Sun offer a unique opportunity to disentangle the nature of various mixing processes, through the distinct signature they leave on period spacings in the gravity mode spectrum. Here we report the detection of numerous gravity modes in a young star with a mass of about seven solar masses. The mean period spacing allows us to estimate the extent of the convective core, and the clear periodic deviation from the mean constrains the location of the chemical transition zone to be at about 10 per cent of the radius and rules out a clear-cut profile. |
| Publication date: 11 Mar 2010 |
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| Astronomy & Astrophysics special issue - The CoRoT space mission: early results |
This A&A special issue is devoted to the CoRoT (Convection, Rotation & planetary
Transits) space mission. Launched on 27 December 2006, the satellite moves in a polar circular
orbit, and the CCD camera of its 27-cm telescope measures stellar-brightness variations with µmag
precision in equatorial fields close to the galactic plane.
The main science goals of CoRoT are to discover exoplanets by the transit method and detect
seismic waves in stars across the entire Hertzsprung-Russell diagram. Objectives also include the
study of stellar activity, stellar rotation, and eclipsing multiple systems.The first results obtained
with CoRoT in all these scientific areas are discussed in the pages of this special issue. |
| Publication date: 22 Oct 2009 |
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| Solar-Like Oscillations in a Massive Star |
| Seismology of stars provides insight into the physical mechanisms taking place in their interior, with modes of oscillation probing different layers. Low-amplitude acoustic oscillations excited by turbulent convection were detected four decades ago in the Sun and more recently in low-mass main-sequence stars. Using data gathered by the Convection Rotation and Planetary Transits mission, we report here on the detection of solar-like oscillations in a massive star, V1449 Aql, which is a known large-amplitude (beta Cephei) pulsator. |
| Publication date: 19 Jun 2009 |
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| The changing phases of extrasolar planet CoRoT-1b |
| Hot Jupiters are a class of extrasolar planet that orbit their parent stars at very short distances. They are expected to be tidally locked, which can lead to a large temperature difference between their daysides and nightsides. Infrared observations of eclipsing systems have yielded dayside temperatures for a number of transiting planets. The day-night contrast of the transiting extrasolar planet HD 189733b was 'mapped' using infrared observations. It is expected that the contrast between the daysides and nightsides of hot Jupiters is much higher at visual wavelengths, shorter than that of the peak emission, and could be further enhanced by reflected stellar light. Here we report the analysis of optical photometric data obtained over 36 planetary orbits of the transiting hot Jupiter CoRoT-1b. The data are consistent with the nightside hemisphere of the planet being entirely black, with the dayside flux dominating the optical phase curve. This means that at optical wavelengths the planet's phase variation is just as we see it for the interior planets in the Solar System. The data allow for only a small fraction of reflected light, corresponding to a geometric albedo of <0.20. |
| Publication date: 28 May 2009 |
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| Non-radial oscillation modes with long lifetimes in giant stars |
| Towards the end of their lives, stars like the Sun greatly expand to become red giant stars. Such evolved stars could provide stringent tests of stellar theory, as many uncertainties of the internal stellar structure accumulate with age. Important examples are convective overshooting and rotational mixing during the central hydrogen-burning phase, which determine the mass of the helium core, but which are not well understood. In principle, analysis of radial and non-radial stellar oscillations can be used to constrain the mass of the helium core. Although all giants are expected to oscillate, it has hitherto been unclear whether non-radial modes are observable at all in red giants, or whether the oscillation modes have a short or a long mode lifetime, which determines the observational precision of the frequencies. Here we report the presence of radial and non-radial oscillations in more than 300 giant stars. For at least some of the giants, the mode lifetimes are of the order of a month. We observe giant stars with equally spaced frequency peaks in the Fourier spectrum of the time series, as well as giants for which the spectrum seems to be more complex. No satisfactory theoretical explanation currently exists for our observations. |
| Publication date: 21 May 2009 |
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| CoRoT Measures Solar-Like Oscillations and Granulation in Stars Hotter Than the Sun |
| Oscillations of the Sun have been used to understand its interior structure. The extension of similar studies to more distant stars has raised many difficulties despite the strong efforts of the international community over the past decades. The CoRoT (Convection Rotation and Planetary Transits) satellite, launched in December 2006, has now measured oscillations and the stellar granulation signature in three main sequence stars that are noticeably hotter than the sun. The oscillation amplitudes are about 1.5 times as large as those in the Sun; the stellar granulation is up to three times as high. The stellar amplitudes are about 25% below the theoretic values, providing a measurement of the nonadiabaticity of the process ruling the oscillations in the outer layers of the stars. |
| Publication date: 24 Oct 2008 |
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| ESA SP-1296: ESA's Report to the 36th COSPAR Meeting |
Scientific editor: R. Marsden
Editor: A. Wilson
The report for the 36th COSPAR Meeting covers, as in previous issues, the missions of the Scientific Programme of ESA in the areas of astronomy, Solar System science and fundamental physics. This year's COSPAR meeting will take place only weeks before the end of the SMART-1 mission to the Moon, a technology project that provided the first European look at our natural satellite from lunar orbit.In October of this year, a new mission will be launched: COROT. ESA, together with a number of countries, is contributing to this unique, French-led project that will provide an insight into the interior of the stars, by means of the asteroseismology technique successfully applied by SOHO. COROT will also perform a systematic search for new extrasolar planets using photometric transits.
The record number of ESA Science Programme missions in operation established at the time of the last report was maintained in 2006 (Huygens having been replaced in the list by Venus Express). Eleven different missions, involving 14 operating spacecraft, are providing excellent science to the worldwide scientific community. The Research and Scientific Support Department (RSSD) is responsible for the science operations of these missions and makes every effort to ensure the best possible science return. The Department also supports the realisation of approved projects in all phases of their development. |
| Publication date: 15 Jun 2006 |
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| The identification of new Be stars in GAUDI |
| The Ground-based Asteroseismology Uniform Database Interface (GAUDI) is the result of the preparatory work performed for the COROT satellite. In the data available in GAUDI we discovered 17 B-type stars that show emission in their Balmer lines and were not known to display such emission before, including at least 16 non-supergiant ones. We thus reclassify those stars as Be stars. These 17 new Be stars increase the number of Be stars in the field of view of COROT by ~25%, which is important for the target selection of the mission. Moreover, ~70% of the discovered Be stars are of late subtypes. Be stars have been mostly found among early subtypes until now, but this could be due to an observational bias. Finally, one of the discovered star is either a slowly rotating shell Be star or a Herbig Be star with a low vsini, which makes this star especially interesting. |
| Publication date: 21 Jan 2005 |
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| ESA SP-1276: ESA's Report to the 35th COSPAR Meeting |
Scientific editor: A. Gimenez
Editor: A. Wilson
The report for the 35th COSPAR Meeting covers, as in previous issues, the missions
of the Scientific Programme of ESA in the areas of astronomy, Solar System
exploration and fundamental physics. This year's COSPAR Meeting occurs only
weeks after the Saturn-orbit insertion of the Cassini spacecraft - carrying Europe's
Huygens probe to explore the atmosphere of Titan - and at the same time as the
launch of the second satellite of the Double Star project. |
| Publication date: 15 Jun 2004 |
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| ESA SP-1259: ESA's Report to the 34th COSPAR Meeting |
Scientific editor: B. Foing
Editor: A. Wilson
The report to the 34th COSPAR Meeting covers the missions of the Scientific Programme of ESA in the areas of astronomy, Solar System exploration and fundamental physics. |
| Publication date: 01 Oct 2002 |
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