The 2003-4 multisite photometric campaign for the Beta Cephei and eclipsing star 16 (EN) Lacertae with an Appendix on 2 Andromedae, the variable comparison star

A multisite photometric campaign for the Beta Cephei and eclipsing variable 16 Lacertae is reported. 749 h of high-quality differential photoelectric Stromgren, Johnson and Geneva time-series photometry were obtained with ten telescopes during 185 nights. After removing the pulsation contribution, an attempt was made to solve the resulting eclipse light curve by means of the computer program EBOP. Although a unique solution was not obtained, the range of solutions could be constrained by comparing computed positions of the secondary component in the Hertzsprung-Russell diagram with evolutionary tracks. For three high-amplitude pulsation modes, the uvy and the Geneva UBG amplitude ratios are derived and compared with the theoretical ones for spherical-harmonic degrees l <= 4. The highest degree, l = 4, is shown to be incompatible with the observations. One mode is found to be radial, one is l = 1, while in the remaining case l = 2 or 3. The present multisite observations are combined with the archival photometry in order to investigate the long-term variation of the amplitudes and phases of the three high-amplitude pulsation modes. The radial mode shows a non-sinusoidal variation on a time-scale of 73 yr. The l = 1 mode is a triplet with unequal frequency spacing, giving rise to two beat-periods, 720.7 d and 29.1 yr. The amplitude and phase of the l = 2 or 3 mode vary on time-scales of 380.5 d and 43 yr. The light variation of 2 And, one of the comparison stars, is discussed in the Appendix.Comment: 18 pages, 19 figures, accepted for publication in MNRA

Asteroseismology of the Beta Cephei star 12 (DD) Lacertae: photometric observations, pulsational frequency analysis and mode identification

We report a multisite photometric campaign for the Beta Cephei star 12 Lacertae. 750 hours of high-quality differential photoelectric Stromgren, Johnson and Geneva time-series photometry were obtained with 9 telescopes during 190 nights. Our frequency analysis results in the detection of 23 sinusoidal signals in the light curves. Eleven of those correspond to independent pulsation modes, and the remainder are combination frequencies. We find some slow aperiodic variability such as that seemingly present in several Beta Cephei stars. We perform mode identification from our colour photometry, derive the spherical degree l for the five strongest modes unambiguously and provide constraints on l for the weaker modes. We find a mixture of modes of 0 <= l <= 4. In particular, we prove that the previously suspected rotationally split triplet within the modes of 12 Lac consists of modes of different l; their equal frequency splitting must thus be accidental. One of the periodic signals we detected in the light curves is argued to be a linearly stable mode excited to visible amplitude by nonlinear mode coupling via a 2:1 resonance. We also find a low-frequency signal in the light variations whose physical nature is unclear; it could be a parent or daughter mode resonantly coupled. The remaining combination frequencies are consistent with simple light-curve distortions. The range of excited pulsation frequencies of 12 Lac may be sufficiently large that it cannot be reproduced by standard models. We suspect that the star has a larger metal abundance in the pulsational driving zone, a hypothesis also capable of explaining the presence of Beta Cephei stars in the LMC.Comment: 12 pages, 7 figures, MNRAS, in pres

Guide d'évaluation de la vulnérabilité et d'analyse multi-critères pour la gestion intégrée des zones humides

WETwin is a research project supported by the European Commission under the Seventh Framework Program. Its overall objective is to enhance the role of wetlands in basin-scale Integrated Water Resources Management (IWRM), with the aim of improving the community service functions while conserving good ecological status. This report aims to be a guideline supporting the integrated and adaptive management of wetlands. This guideline is embedded into a Conceptual Framework, which is introduced in Chapter 2. Further, the guideline consists of two main parts: Vulnerability Assessment (VA) in Chapter 3, and Multi-Criteria decision Analysis (MCA) in Chapter 4. The descriptions of these methodologies are illustrated by examples from the WETwin case studies. Also, references have been incorporated into the texts with regard to relevant publications and to other WETwin project reports. In this way, the guideline covers all relevant outcomes and results of WETwin, and it also works as a meta-document for the most important deliverables of the project. Chapter 5 at the end of the report draws conclusions and gives recommendations for the joint use of VA and MCA. The targeted users of this guideline are professionals, who are in charge of elaborating wetland management plans

2MASS J0516288+260738: Discovery of the first eclipsing late K + Brown dwarf binary system

Original article available at: http://www.aanda.org/--Copyright The European Southern Observatory DOI : 10.1051/0004-6361:20031241We report the discovery of a new eclipsing system less than one arcminute south of the pulsating DB white dwarf KUV05134+2605. The object could be identified with the point source 2MASSJ0516288+260738 published by the Two Micron All Sky Survey.We present and discuss the first light curves as well as some additional colour and spectral information. The eclipse period of the system is 1.29 d, and, assuming this to be identical to the orbital period, the best light curve solution yields a mass ratio of m2/m1 = 0.11, a radius ratio of r2/r1 ≈ 1 and an inclination of 74◦. The spectral anaylsis results in a Teff = 4200 K for the primary. On this basis, we suggest that the new system probably consists of a late K + Brown dwarf (which would imply a system considerably younger than ≈0.01 Gyr to have r2/r1 ≈ 1), and outline possible future observations.Peer reviewe

Analyse de la capacité institutionnelle pour la gestion des zones humides et la gestion intégrée des ressource en eau dans les zones humides de Gemenc, Ga-Mampa, Nabajjuzi et Namatala

WETwin is a research project supported by the European Commission under the Seventh Framework Program. Its overall objective is to enhance the role of wetlands in basin-scale Integrated Water Resources Management (IWRM), with the aim of improving the community service functions while conserving good ecological status. This report presents the results of the analysis of the institutional capacity to implement IWRM and existing guidelines in selected case study sites of the WETwin project (Gemenc (Hungary), Ga-Mampa (South Africa), Nabajjuzi and Namatala (Uganda)). It includes: i) a presentation of the conceptual approach used to analyze institutional capacity in case studies, in particular, the main concepts and definitions of institutional capacity and its links to performance of the wetland management institutions; ii) a description of the methodology used for the analysis of four case studies; iii) the detailed assessment of the components of institutional capacity using the cross-case comparison method, as well as a discussion of the major findings of the application of the methodology in the case studies; and iv) a summary of all the lessons learnt during this exercise and recommendations for improvements of the institutional capacity in the case study areas and in wetland management in general

Rapport sur l'analyse de la vulnérabilité initiale pour chaque cas d'étude

WETwin is a research project supported by the European Commission under the Seventh Framework Program. Its overall objective is to enhance the role of wetlands in basin-scale Integrated Water Resources Management (IWRM), with the aim of improving the community service functions while conserving good ecological status. This report presents the initial vulnerability assessment of case study wetlands to global changes conducted under the WETwin project. This includes: i) the development of three global changes scenarios in line with the IPCC SRES scenarios but complemented with recent trends and ideas derived from Millennium Assessment Scenarios; ii) the development of DPSIR (Driving force, Pressure, State, Impact, Response) chains for each case study to identify and explore the major environmental and livelihood problems (impacts) at the study sites; iii) the definition of site-specific storylines to focus on specific research questions and also support the development of regional scenarios; and iv) initial vulnerability assessment for the southern case studies. Results are provided for each of the seven case study sites of the WETwin project in Europe, Africa and South America

Identification des options et solutions de gestion pour les cas d'étude de WETwin

WETwin is a research project supported by the European Commission under the Seventh Framework Program. Its overall objective is to enhance the role of wetlands in basin-scale Integrated Water Resources Management (IWRM), with the aim of improving the community service functions while conserving good ecological status. This report addresses formulation of management responses to the drivers, pressures and impacts on wetlands identified in case study sites. Within the WETwin conceptual framework a range of options are identified from which management solutions can be built up. In principle, each option can be carried out alone, but in practice, combinations of several responses are likely to be combined into comprehensive management solutions. Further this document identifies performance indicators used for the evaluation of the management solutions and describes a set of models and expert assessment tools used for this purpose. An overview of generic responses available for wetland management and rehabilitation is presented. Management responses are separated into groups of similar measures targeting specific wetland components. Such a grouping gives a clearer overview of possible measures, and facilitates transfer of these generic groups to other wetlands. A brief overview of the process of identifying, elaborating and combining management options into implementable packages of management solutions is then provided. Site-specific management options and solutions are presented for seven case studies: Ga-Mampa, Inner Niger Delta, Nabajjuzi, Namatala, Abras de Mantequilla, Lobau and Gemenc wetlands