High-Resolution Spectroscopy of the Transiting Planet Host Star TrES-1

We report on a spectroscopic determination of the stellar parameters and chemical abundances for the parent star of the transiting planet TrES-1. Based on a detailed analysis of iron lines in our Keck and Hobby-Eberly Telescope spectra, we derive Teff = 5250 ± 75 K, log g = 4.6 ± 0.2, and [Fe/H] = 0.00 ± 0.09. By measuring the Ca II activity indicator and by putting useful upper limits on the Li abundance, we constrain the age of TrES-1 to be 2.5 ± 1.5 Gyr. By comparing theoretical stellar evolution models with the observational parameters, we obtain M* = 0.89 ± 0.05 M⊙ and R* = 0.83 ± 0.05 R⊙. Our improved estimates of the stellar parameters are utilized in a new analysis of the transit photometry of TrES-1 to derive a mass Mp = (0.76 ± 0.05) MJ a radius RP = 1.04-0.05+0.08RJ, and an inclination i = 89.5-1.3+0.5 deg. The improved planetary mass and radius estimates provide the grounds for new crucial tests of theoretical models of evolution and evaporation of irradiated extrasolar giant planets

S4N: A Spectroscopic Survey of Stars in the Solar Neighborhood

[ABRIDGED] We report the results of a high-resolution spectroscopic survey of all the stars more luminous than Mv = 6.5 mag within 14.5 pc from the Sun. We derive stellar parameters and perform a preliminary abundance and kinematic analysis of the F-G-K stars in the sample. The inferred metallicity ([Fe/H]) distribution is centered at about -0.1 dex, and shows a standard deviation of 0.2 dex. We identify a number of metal-rich K-type stars which appear to be very old, confirming the claims for the existence of such stars in the solar neighborhood. With atmospheric effective temperatures and gravities derived independently of the spectra, we find that our classical LTE model-atmosphere analysis of metal-rich (and mainly K-type) stars provides discrepant abundances from neutral and ionized lines of several metals. Based on transitions of majority species, we discuss abundances of 16 chemical elements. In agreement with earlier studies we find that the abundance ratios to iron of Si, Sc, Ti, Co, and Zn become smaller as the iron abundance increases until approaching the solar values, but the trends reverse for higher iron abundances. At any given metallicity, stars with a `low' galactic rotational velocity tend to have high abundances of Mg, Si, Ca, Sc, Ti, Co, Zn, and Eu, but low abundances of Ba, Ce, and Nd. The Sun appears deficient by roughly 0.1 dex in O, Si, Ca, Sc, Ti, Y, Ce, Nd, and Eu, compared to its immediate neighbors with similar iron abundances.Comment: 24 pages, 19 figures, to appear in A&A; data can be accessed from http://hebe.as.utexas.edu/s4n/ or http://www.astro.uu.se/~s4n

High Resolution Spectroscopy and Spectropolarimetry of some late F-/early G-type sun-like stars as targets for Zeeman Doppler imaging

High resolution spectroscopy and spectropolarimetry have been undertaken at the Anglo-Australian Telescope in order to identify suitable targets for magnetic studies of young sun-like stars, for the proxy study of early solar evolution. This study involved the investigation of some variable late F-/early G-type sun-like stars originally identified by the Hipparcos mission. Of the 38 stars observed for this study, HIP 31021, HIP 64732, HIP 73780 were found to be spectroscopic binary stars while HIP 19072, HIP 67651 and HIP 75636 are also likely to be binaries while HIP 33111 could even be a triple system. Magnetic fields were detected on a number of the survey stars: HIP 21632, HIP 43720, HIP 48770, HIP 62517, HIP 71933, HIP 77144, HIP 89829, HIP 90899 and HIP 105388, making these stars good candidates for follow-up Zeeman Doppler imaging studies.Comment: 16 pages, 16 figures, 4 tables Accepted for publication in PAS

Depicting the battle between nectarine and Monilinia laxa: the fruit developmental stage dictates the effectiveness of the host defenses and the pathogen’s infection strategies

Infections by the fungus Monilinia laxa, the main cause of brown rot in Europe, result in considerable losses of stone fruit. Herein, we present a comprehensive transcriptomic approach to unravel strategies deployed by nectarine fruit and M. laxa during their interaction. We used M. laxa-inoculated immature and mature fruit, which was resistant and susceptible to brown rot, respectively, to perform a dual RNA-Seq analysis. In immature fruit, host responses, pathogen biomass, and pathogen transcriptional activity peaked at 14–24 h post inoculation (hpi), at which point M. laxa appeared to switch its transcriptional response to either quiescence or death. Mature fruit experienced an exponential increase in host and pathogen activity beginning at 6 hpi. Functional analyses in both host and pathogen highlighted differences in stage-dependent strategies. For example, in immature fruit, M. laxa unsuccessfully employed carbohydrate-active enzymes (CAZymes) for penetration, which the fruit was able to combat with tightly regulated hormone responses and an oxidative burst that challenged the pathogen’s survival at later time points. In contrast, in mature fruit, M. laxa was more dependent on proteolytic effectors than CAZymes, and was able to invest in filamentous growth early during the interaction. Hormone analyses of mature fruit infected with M. laxa indicated that, while jasmonic acid activity was likely useful for defense, high ethylene activity may have promoted susceptibility through the induction of ripening processes. Lastly, we identified M. laxa genes that were highly induced in both quiescent and active infections and may serve as targets for control of brown rot.info:eu-repo/semantics/publishedVersio

Deliverable D6a: Regional climatic characteristics for the European sites at specific times: the dynamical downscaling. Work Package 2, Simulation of the future evolution of the biosphere system using the hierarchical strategy. Modelling Sequential Biosphere Systems under Climate Change for Radioactive Waste Disposal (BIOCLIM)

The overall aim of BIOCLIM is to assess the possible long-term impacts due to climate change on the safety of radioactive waste repositories in deep formations. This aim is addressed through the following specific objectives: • Development of practical and innovative strategies for representing sequential climatic changes to the geosphere-biosphere system for existing sites over central Europe, addressing the timescale of one million years, which is relevant to the geological disposal of radioactive waste. • Exploration and evaluation of the potential effects of climate change on the nature of the biosphere systems used to assess the environmental impact. • Dissemination of information on the new methodologies and the results obtained from the project among the international waste management community for use in performance assessments of potential or planned radioactive waste repositories. The BIOCLIM project is designed to advance the state-of-the-art of biosphere modelling for use in Performance Assessments. Therefore, two strategies are developed for representing sequential climatic changes to geosphere-biosphere systems. The hierarchical strategy successively uses a hierarchy of climate models. These models vary from simple 2-D models, which simulate interactions between a few aspects of the Earth system at a rough surface resolution, through General Circulation Model (GCM) and vegetation model, which simulate in great detail the dynamics and physics of the atmosphere, ocean and biosphere, to regional models, which focus on the European regions and sites of interest. Moreover, rule-based and statistical downscaling procedures are also considered. Comparisons are provided in terms of climate and vegetation cover at the selected times and for the study regions. The integrated strategy consists of using integrated climate models, representing all the physical mechanisms important for long-term continuous climate variations, to simulate the climate evolution over many millennia. These results are then interpreted in terms of regional climatic changes using rule-based and statistical downscaling approaches. This deliverable, D6a, focuses on the hierarchical strategy, and in particular the MAR simulations. According to the hierarchical strategy developed in the BIOCLIM project to predict future climate, six BIOCLIM experiments were run with the MAR model. In addition to these experiments a baseline experiment, presenting the present-day climate simulated by MAR, was also undertaken. In the first step of the hierarchical strategy the LLN 2-D NH climate model simulated the gross features of the climate of the next 1 Myr [Ref.1]. Six snapshot experiments were selected from these results. In a second step a GCM and a biosphere model were used to simulate in more detail the climate of the selected time periods. These simulations were performed on a global scale [Ref.1]. The third step of the procedure is to derive the regional features of the climate at the same time periods. Therefore the results of the GCM are used as boundary conditions to force the regional climate model (MAR) for the six selected periods and the baseline simulation. The control simulation (baseline) corresponds to the regional climate simulated under present-day conditions, both insolation forcing and atmospheric CO2 concentration. All the BIOCLIM simulations are compared to that baseline simulation. In addition, other comparisons will also be presented. Tableau 1 summarises the characteristics of these BIOCLIM experiments already presented in [Ref.1] and [Ref.2]

The Spectroscopic Orbit of the Planetary Companion Transiting HD209458

We report a spectroscopic orbit with period P = 3.52433 +/- 0.00027 days for the planetary companion that transits the solar-type star HD209458. For the metallicity, mass, and radius of the star we derive [Fe/H] = 0.00 +/- 0.02, M = 1.1 +/- 0.1 solar masses, and R = 1.3 +/- 0.1 solar radii. This is based on a new analysis of the iron lines in our HIRES template spectrum, and also on the absolute magnitude and color of the star, and uses isochrones from four different sets of stellar evolution models. Using these values for the stellar parameters we reanalyze the transit data and derive an orbital inclination of i = 85.2 +/- 1.4 degrees. For the planet we derive a mass of Mp = 0.69 +/- 0.05 Jupiter masses, a radius of Rp = 1.54 +/- 0.18 Jupiter radii, and a density of 0.23 +/- 0.08 grams per cubic cm.Comment: 11 pages, 1 figure, 2 tables, LaTex, aastex, accepted for publication by ApJ Letter

Deliverable D8a: Development of the rule-based downscaling methodology for BIOCLIM Workpackage 3. Work Package 3, Simulation of the future evolution of the biosphere system using the hierarchical strategy. Modelling Sequential Biosphere Systems under Climate Change for Radioactive Waste Disposal (BIOCLIM)

One of the tasks of BIOCLIM WP3 was to develop a rule-based approach for downscaling from the MoBidiC model of intermediate complexity (see Ref.1) in order to provide consistent estimates of monthly temperature and precipitation for the specific regions of interest to BIOCLIM (Central Spain, Central England and Northeast France, together with Germany and the Czech Republic). Such an approach has been developed and used in a previous study funded by Nirex to downscale output from an earlier version of this climate model covering the Northern Hemisphere only, LLN 2-D NH, to Central England, and evaluated using palaeoclimate proxy data and General Circulation Model (GCM) output for this region. This previous study [Ref.2] provides the starting point for the BIOCLIM work. A statistical downscaling methodology has been developed by Philippe Marbaix of CEA/LSCE for use with the second climate model of intermediate complexity used in BIOCLIM – CLIMBER-GREMLINS (see Ref.1). This statistical methodology is described in Deliverable D8b [Ref.3]. Inter-comparisons of all the downscaling methodologies used in BIOCLIM (including the dynamical methods applied in WP2 – see Ref.4 and Ref.5) are discussed in Deliverable D10-12 [Ref.6]. The rule-based methodology assigns climate states or classes to a point on the time continuum of a region according to a combination of simple threshold values which can be determined from the coarse scale climate model. Once climate states or classes have been defined, monthly temperature and precipitation climatologies are constructed using analogue stations identified from a data base of present-day climate observations. The most appropriate climate classification for BIOCLIM purposes is the Køppen/Trewartha scheme (Ref.7 ; see Appendix 1). This scheme has the advantage of being empirical, but only requires monthly averages of temperature and precipitation as input variables

Deliverable D7: Continuous climate evolution scenarios over western Europe (1000 km) scale. Work Package 2, Simulation of the future evolution of the biosphere system using the hierarchical strategy. Modelling Sequential Biosphere Systems under Climate Change for Radioactive Waste Disposal (BIOCLIM)

The overall aim of BIOCLIM is to assess the possible long term impacts due to climate change on the safety of radioactive waste repositories in deep formations. This aim is addressed through the following specific objectives: • Development of practical and innovative strategies for representing sequential climatic changes to the geosphere-biosphere system for existing sites over central Europe, addressing the timescale of one million years, which is relevant to the geological disposal of radioactive waste. • Exploration and evaluation of the potential effects of climate change on the nature of the biosphere systems used to assess the environmental impact. • Dissemination of information on the new methodologies and the results obtained from the project among the international waste management community for use in performance assessments of potential or planned radioactive waste repositories. A key point of the project is therefore to develop strategies for representing sequential long-term climatic changes by addressing time scales of relevance to geological disposal of solid radioactive wastes. The integrated strategy, which first step is described in this deliverable (D7), consists of building an integrated, dynamic climate model, to represent all the known important mechanisms for long term climatic variations. The time-dependent results will then be interpreted in terms of regional climate using rulebased and statistical downscaling approaches. Therefore, the continuous simulation of the climate evolution of the next 200 000 years selected for study is a major objective of the BIOCLIM project. This requires models that account for the simultaneous evolution of the atmosphere, biosphere, land-ice and the ocean. To be able to perform several 200 000-yearlong transient climate simulations, the models have to include all these components, but also need to be simple enough to run fast. Therefore, climate models of intermediate complexity have been chosen to complete this part of the BIOCLIM project. In the present deliverable, we report on the results of two such models, MoBidiC (Louvain-la-Neuve) and CLIMBER-GREMLINS (LSCE). The overall objective of the work presented here is the simulation of the climate of the next 200 000 years for three different CO2 scenarios [Ref.1]. However, both models used for this work have been either modified for the project (MoBidiC) or developed within the project (CLIMBERGREMLINS). Therefore their performance, and the modifications and developments needed to be documented, especially as far as their ability to reproduce past and different climates is concerned. Therefore, a large section of the present deliverable is devoted to the evaluation of the models through past climate simulations. The deliverable is structured as follows: first, a brief description of the models is given. In the second section, results from the models for past climate situations are presented. The third section deals with the future climate simulations devised for the BIOCLIM project: for each CO2 scenario, the results of the two models are compared. It is emphasized that the model results, especially those for CLIMBER-GREMLINS, should be regarded as illustrations of possibilities rather than absolute predictions of climate evolution. The novel approach to long-term climate change adopted in BIOCLIM is based on research tools under continuing development, notably, the CLIMBER-GREMLINS model

Starspots on the fastest rotators in the Beta Pic moving group

Aims: We carried out high-resolution spectroscopy and BV(I)_C photometric monitoring of the two fastest late-type rotators in the nearby Beta Pictoris moving group, HD199143 (F7V) and CD-641208 (K7V). The motivation for this work is to investigate the rotation periods and photospheric spot patterns of these very young stars, with a longer term view to probing the evolution of rotation and magnetic activity during the early phases of main-sequence evolution. We also aim to derive information on key physical parameters, such as rotational velocity and rotation period. Methods: We applied maximum entropy (ME) and Tikhonov regularizing (TR) criteria to derive the surface spot map distributions of the optical modulation observed in HD199143 (F7 V) and CD-641208 (K7V). We also used cross-correlation techniques to determine stellar parameters such as radial velocities and rotational velocities. Lomb-Scargle periodograms were used to obtain the rotational periods from differential magnitude time series. Results: We find periods and inclinations of 0.356 days and 21.5deg for HD199143, and 0.355 days and 50.1deg for CD-641208. The spot maps of HD199143 obtained from the ME and TR methods are very similar, although the latter gives a smoother distribution of the filling factor. Maps obtained at two different epochs three weeks apart show a remarkable increase in spot coverage amounting to ~7% of the surface of the photosphere over a time period of only ~20 days. The spot maps of CD-641208 from the two methods show good longitudinal agreement, whereas the latitude range of the spots is extended to cover the whole visible hemisphere in the TR map. The distributions obtained from the first light curve of HD199143 show the presence of an extended and asymmetric active longitude with the maximum filling factor at longitude ~325degree.Comment: Accepted by A&A. 13 pages, 13 figures (4 online included), 5 Table

Deliverable D8b: Development of the physical/statistical downscaling methodology and application to climate model CLIMBER for BIOCLIM Workpackage 3. Work Package 3, Simulation of the future evolution of the biosphere system using the hierarchical strategy. Modelling Sequential Biosphere Systems under Climate Change for Radioactive Waste Disposal (BIOCLIM)

The overall aim of BIOCLIM is to assess the possible long term impacts due to climate change on the safety of radioactive waste repositories in deep formations. This aim is addressed through the following specific objectives: • Development of practical and innovative strategies for representing sequential climatic changes to the geosphere-biosphere system for existing sites over central Europe, addressing the timescale of one million years, which is relevant to the geological disposal of radioactive waste. • Exploration and evaluation of the potential effects of climate change on the nature of the biosphere systems used to assess the environmental impact. • Dissemination of information on the new methodologies and the results obtained from the project among the international waste management community for use in performance assessments of potential or planned radioactive waste repositories. This deliverable has the following specific motivations and objectives: Its main aim is to provide time series of climatic variables at the high resolution as needed by performance assessment (PA) of radioactive waste repositories, on the basis of coarse output from the CLIMBER-GREMLINS climate model