In this white paper, we recommend the European Space Agency plays a proactive role in developing a global collaborative effort to construct a large high-contrast imaging space telescope, e.g. as... Show moreIn this white paper, we recommend the European Space Agency plays a proactive role in developing a global collaborative effort to construct a large high-contrast imaging space telescope, e.g. as currently under study by NASA. Such a mission will be needed to characterize a sizable sample of temperate Earth-like planets in the habitable zones of nearby Sun-like stars and to search for extraterrestrial biological activity. We provide an overview of relevant European expertise, and advocate ESA to start a technology development program towards detecting life outside the Solar system. Show less
Exoplanet science is one of the most thriving fields of modern astrophysics. A major goal is the atmospheric characterization of dozens of small, terrestrial exoplanets in order to search for... Show moreExoplanet science is one of the most thriving fields of modern astrophysics. A major goal is the atmospheric characterization of dozens of small, terrestrial exoplanets in order to search for signatures in their atmospheres that indicate biological activity, assess their ability to provide conditions for life as we know it, and investigate their expected atmospheric diversity. None of the currently adopted projects or missions, from ground or in space, can address these goals. In this White Paper we argue that a large space-based mission designed to detect and investigate thermal emission spectra of terrestrial exoplanets in the MIR wavelength range provides unique scientific potential to address these goals and surpasses the capabilities of other approaches. While NASA might be focusing on large missions that aim to detect terrestrial planets in reflected light, ESA has the opportunity to take leadership and spearhead the development of a large MIR exoplanet mission within the scope of the "Voyage 2050" long-term plan establishing Europe at the forefront of exoplanet science for decades to come. Given the ambitious science goals of such a mission, additional international partners might be interested in participating and contributing to a roadmap that, in the long run, leads to a successful implementation. A new, dedicated development program funded by ESA to help reduce development and implementation cost and further push some of the required key technologies would be a first important step in this direction. Ultimately, a large MIR exoplanet imaging mission will be needed to help answer one of mankind's most fundamental questions: "How unique is our Earth?" Show less
Olofsson, J.; Holstein, R.G. van; Boccaletti, A.; Janson, M.; Thébault, P.; Gratton, R.; ... ; Roux, A. 2018
We present the first near-IR scattered light detection of the transitional disk associated with the Herbig Ae star MWC 758 using data obtained as part of the Strategic Exploration of Exoplanets... Show moreWe present the first near-IR scattered light detection of the transitional disk associated with the Herbig Ae star MWC 758 using data obtained as part of the Strategic Exploration of Exoplanets and Disks with Subaru, and 1.1 {$μ$}m Hubble Space Telescope/NICMOS data. While submillimeter studies suggested there is a dust-depleted cavity with r = 0.''35, we find scattered light as close as 0.''1 (20-28 AU) from the star, with no visible cavity at H, K', or K$_s$ . We find two small-scaled spiral structures that asymmetrically shadow the outer disk. We model one of the spirals using spiral density wave theory, and derive a disk aspect ratio of h ~{} 0.18, indicating a dynamically warm disk. If the spiral pattern is excited by a perturber, we estimate its mass to be 5$^{+3}$ $_{- 4}$ M$_J$ , in the range where planet filtration models predict accretion continuing onto the star. Using a combination of non-redundant aperture masking data at L' and angular differential imaging with Locally Optimized Combination of Images at K' and K$_s$ , we exclude stellar or massive brown dwarf companions within 300 mas of the Herbig Ae star, and all but planetary mass companions exterior to 0.''5. We reach 5{$σ$} contrasts limiting companions to planetary masses, 3-4 M$_J$ at 1.''0 and 2 M$_J$ at 1.''55, using the COND models. Collectively, these data strengthen the case for MWC 758 already being a young planetary system. Show less
Grady, C.; Muto, T.; Hashimoto, J.; Fukagawa, M.; Currie, T.; Biller, B.; ... ; Tamura, M. 2013
We present the first near-IR scattered light detection of the transitional disk associated with the Herbig Ae star MWC 758 using data obtained as part of the Strategic Exploration of Exoplanets and... Show moreWe present the first near-IR scattered light detection of the transitional disk associated with the Herbig Ae star MWC 758 using data obtained as part of the Strategic Exploration of Exoplanets and Disks with Subaru, and 1.1 {$μ$}m Hubble Space Telescope/NICMOS data. While submillimeter studies suggested there is a dust-depleted cavity with r = 0.''35, we find scattered light as close as 0.''1 (20-28 AU) from the star, with no visible cavity at H, K', or K$_s$ . We find two small-scaled spiral structures that asymmetrically shadow the outer disk. We model one of the spirals using spiral density wave theory, and derive a disk aspect ratio of h ~{} 0.18, indicating a dynamically warm disk. If the spiral pattern is excited by a perturber, we estimate its mass to be 5$^{+3}$ $_{- 4}$ M$_J$ , in the range where planet filtration models predict accretion continuing onto the star. Using a combination of non-redundant aperture masking data at L' and angular differential imaging with Locally Optimized Combination of Images at K' and K$_s$ , we exclude stellar or massive brown dwarf companions within 300 mas of the Herbig Ae star, and all but planetary mass companions exterior to 0.''5. We reach 5{$σ$} contrasts limiting companions to planetary masses, 3-4 M$_J$ at 1.''0 and 2 M$_J$ at 1.''55, using the COND models. Collectively, these data strengthen the case for MWC 758 already being a young planetary system. Show less
On 15 December 2006 Marloes Janson (Zentrum Moderner Orient, Berlin) and Dorothea Schulz (Indiana University) convened a workshop titled “Piety, Responsibility, Subjectivity: Reconfigurations of... Show moreOn 15 December 2006 Marloes Janson (Zentrum Moderner Orient, Berlin) and Dorothea Schulz (Indiana University) convened a workshop titled “Piety, Responsibility, Subjectivity: Reconfigurations of the Moral Economy of Gender Relations in Contemporary Muslim Africa” at the Snoeck Hurgronje Huis, Leiden. The workshop and the subsequent public event were sponsored by ISIM, in cooperation with the Knowledge Centre Religion and Development and ZemZem, Journal for the Middle East, North Africa, and Islam. Show less
Over the years, the Tablighi Jamaat has expanded into what is probably indeed the largest Islamic movement of contemporary times. Despite its magnitude, its impact in sub-Saharan Africa has been... Show moreOver the years, the Tablighi Jamaat has expanded into what is probably indeed the largest Islamic movement of contemporary times. Despite its magnitude, its impact in sub-Saharan Africa has been largely neglected. This article, based on ethnographic field research, focuses on the Jamaat in The Gambia (West Africa) where particularly youth convert to Tablighi ideology, in what could be seen as a form of rebellion against the authority of their elders. In the process, established religious and social values are redefined. Show less
Gambian griottes, or female bards, are in a serious predicament. Islamic ethics prescribe that women should behave in a modest way, while conversely the griottes' very profession implies that they... Show moreGambian griottes, or female bards, are in a serious predicament. Islamic ethics prescribe that women should behave in a modest way, while conversely the griottes' very profession implies that they stand out by their behaviour and the way they dress. How do these women reconcile their identity as female performers with Islamic values? The Gambia is an interesting setting in which to explore this question because of its long history with Islam. There was even talk that President Jammeh wanted to impose the sharica in this small West African country. Show less
