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See detailThe Search for Worlds Like Our Own
Fridlund, Malcolm; Eiroa, Carlos; Henning, Thomas et al

in Astrobiology (2010), 10(1), 5-17

The direct detection of Earth-like exoplanets orbiting nearby stars and the characterization of such planets -- particularly, their evolution, their atmospheres, and their ability to host life ... [more ▼]

The direct detection of Earth-like exoplanets orbiting nearby stars and the characterization of such planets -- particularly, their evolution, their atmospheres, and their ability to host life -- constitute a significant problem. The quest for other worlds as abodes of life has been one of mankind's great questions for several millennia. For instance, as stated by Epicurus 300 BC: Other worlds, with plants and other living things, some of them similar and some of them different from ours, must exist. Demokritos from Abdera (460-370 BC), the man who invented the concept of indivisible small parts - atoms - also held the belief that other worlds exist around the stars and that some of these worlds may be inhabited by life-forms. The idea of the plurality of worlds and of life on them has since been held by scientists like Johannes Kepler and William Herschel, among many others. Here, one must also mention Giordano Bruno. Born in 1548, Bruno studied in France and came into contact with the teachings of Nicolas Copernicus. He wrote the book De l'Infinito, Universo e Mondi in 1584, in which he claimed that the Universe was infinite, that it contained an infinite amount of worlds like Earth, and that these worlds were inhabited by intelligent beings. At the time, this was extremely controversial, and eventually Bruno was arrested by the church and burned at the stake in Rome in 1600, as a heretic, for promoting this and other equally confrontational issues (though it is unclear exactly which idea was the one that ultimately brought him to his end). In all the aforementioned cases, the opinions and results were arrived at through reasoning--not by experiment. We have only recently acquired the technological capability to observe planets orbiting stars other than 6our Sun; acquisition of this capability has been a remarkable feat of our time. We show in this introduction to the Habitability Primer that mankind is at the dawning of an age when, by way of the scientific method and 21st-century technology, we will be able to answer this fascinating controversial issue that has persisted for at least 2500 years. [less ▲]

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See detailCharacterisation of disks around YSOs with GENIE
Kaltenegger, Lisa; Absil, Olivier ULg; Eiroa, Carlos et al

in Fridlund, Malcolm; Henning, Thomas (Eds.) Towards Other Earths: DARWIN/TPF and the Search for Extrasolar Terrestrial Planets (2003, October 01)

Recent interferometric observations show that the interfered near-IR size of the circumstellar material around Young Stellar Object (YSO) are larger than those expected from accretion disk models. There ... [more ▼]

Recent interferometric observations show that the interfered near-IR size of the circumstellar material around Young Stellar Object (YSO) are larger than those expected from accretion disk models. There are currently different models that account for the excess IR emission of Young Stellar Objects (YSO). At the same time, the answers to many questions on the evolutionary status and the origin of the activity and variability depend critically on the relative importance of circumstellar distribution of material in disks or envelopes at different spatial scales. Operating at mid-infrared wavelengths, the Ground-based European Nulling Interferometer Experiment (GENIE) will be particularly sensitive to warm circumstellar dust and will thus provide the opportunity to characterize dust disks around YSOs. Observations with GENIE will enable us to investigate the properties of the circumstellar dust, which are responsible for the excess near-infrared fluxes. The nulling of the central star will bring out the disk in much more detail and hence put stronger constraints on these models. [less ▲]

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See detailDarwin ground-based European nulling interferometer experiment (GENIE)
Gondoin, Philippe; Absil, Olivier ULg; Fridlund, C V Malcolm et al

in Traub, Wesley (Ed.) Interferometry for Optical Astronomy II (2003, February 01)

Darwin is one of the most challenging space projects ever considered by the European Space Agency (ESA). Its principal objectives are to detect Earth-like planets around nearby stars and to characterize ... [more ▼]

Darwin is one of the most challenging space projects ever considered by the European Space Agency (ESA). Its principal objectives are to detect Earth-like planets around nearby stars and to characterize their atmospheres. Darwin is conceived as a space "nulling interferometer" which makes use of on-axis destructive interferences to extinguish the stellar light while keeping the off-axis signal of the orbiting planet. Within the frame of the Darwin program, the European Space Agency (ESA) and the European Southern Observatory (ESO) intend to build a ground-based technology demonstrator called GENIE (Ground based European Nulling Interferometry Experiment). Such a ground-based demonstrator built around the Very Large Telescope Interferometer (VLTI) in Paranal will test some of the key technologies required for the Darwin Infrared Space Interferometer. It will demonstrate that nulling interferometry can be achieved in a broad mid-IR band as a precursor to the next phase of the Darwin program. The present paper will describe the objectives and the status of the project. [less ▲]

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