Dynamical stability analysis of the HD202206 system and constraints to the planetary orbits

Long-term precise Doppler measurements with the CORALIE spectrograph revealed the presence of two massive companions to the solar-type star HD202206. Although the three-body fit of the system is unstable, it was shown that a 5:1 mean motion resonance exists close to the best fit, where the system is stable. We present here an extensive dynamical study of the HD202206 system aiming at constraining the inclinations of the two known companions, from which we derive possible ranges of value for the companion masses. We study the long term stability of the system in a small neighborhood of the best fit using Laskar's frequency map analysis. We also introduce a numerical method based on frequency analysis to determine the center of libration mode inside a mean motion resonance. We find that acceptable coplanar configurations are limited to inclinations to the line of sight between 30 and 90 degrees. This limits the masses of both companions to roughly twice the minimum. Non coplanar configurations are possible for a wide range of mutual inclinations from 0 to 90 degrees, although $\Delta\Omega = 0 [\pi]$ configurations seem to be favored. We also confirm the 5:1 mean motion resonance to be most likely. In the coplanar edge-on case, we provide a very good stable solution in the resonance, whose $\chi^2$ does not differ significantly from the best fit. Using our method to determine the center of libration, we further refine this solution to obtain an orbit with a very low amplitude of libration, as we expect dissipative effects to have dampened the libration.Comment: 14 pages, 18 figure

The HARPS search for southern extra-solar planets XIX. Characterization and dynamics of the GJ876 planetary system

Precise radial-velocity measurements for data acquired with the HARPS spectrograph infer that three planets orbit the M4 dwarf star GJ876. In particular, we confirm the existence of planet "d", which orbits every 1.93785 days. We find that its orbit may have significant eccentricity (e=0.14), and deduce a more accurate estimate of its minimum mass of 6.3 Earth masses. Dynamical modeling of the HARPS measurements combined with literature velocities from the Keck Observatory strongly constrain the orbital inclinations of the "b" and "c" planets. We find that i_b = 48.9 degrees and i_c = 48.1 degrees, which infers the true planet masses of M_b = 2.64 Jupiter masses and M_c = 0.83 Jupiter masses, respectively. Radial velocities alone, in this favorable case, can therefore fully determine the orbital architecture of a multi-planet system, without the input from astrometry or transits. The orbits of the two giant planets are nearly coplanar, and their 2:1 mean motion resonance ensures stability over at least 5 Gyr. The libration amplitude is smaller than 2 degrees, suggesting that it was damped by some dissipative process during planet formation. The system has space for a stable fourth planet in a 4:1 mean motion resonance with planet "b", with a period around 15 days. The radial velocity measurements constrain the mass of this possible additional planet to be at most that of the Earth.Comment: 10 pages, 10 figures, accepted for publication in Astronomy & Astrophysic

The HARPS search for southern extra-solar planets. IX. mu Ara, a system with four planets

The mu Ara planetary system is rather complex: It contains two already known planets, mu Ara b with P=640 days and mu Ara c with P=9.64 days, and a third companion on a wide but still poorly defined orbit. Even with three planets in the system, the data points keep anomalously high dispersion around the fitted solution. The high residuals are only partially due to the strong p-mode oscillations of the host star. We have therefore studied in this paper the possible presence of a fourth planet in the system. During the past years we have carried out additional and extremely precise radial-velocity measurements with the HARPS spectrograph. We provide in this paper a full orbital solution of the planetary system around mu Ara. It turns out to be the second system known to harbor 4 planetary companions. Thanks to the new data points acquired with HARPS we can confirm the presence of mu Ara c at P=9.64 days, which produces a coherent RV signal over more than two years. The new orbital fit sets the mass of mu Ara c to 10.5 M_Earth. Furthermore, we present the discovery of mu Ara d, a new planet on an almost circular 310 days-period and with a mass of 0.52 M_Jup. Finally, we give completely new orbital parameters for the longest-period planet, mu Ara e. It is the first time that this companion is constrained by radial-velocity data into a dynamical stable orbit, which leaves no doubt about its planetary nature. (Abridged).Comment: 11 pages, 8 low-resolution figures. Submitted to A&A on August 5, 200

Human Cysteine Cathepsins Are Not Reliable Markers of Infection by Pseudomonas aeruginosa in Cystic Fibrosis

Cysteine cathepsins have emerged as new players in inflammatory lung disorders. Their activities are dramatically increased in the sputum of cystic fibrosis (CF) patients, suggesting that they are involved in the pathophysiology of CF. We have characterized the cathepsins in CF expectorations and evaluated their use as markers of colonization by Pseudomonas aeruginosa. The concentrations of active cathepsins B, H, K, L and S were the same in P. aeruginosa-positive (19 Ps+) and P. aeruginosa-negative (6 Ps−) samples, unlike those of human neutrophil elastase. Also the cathepsin inhibitory potential and the cathepsins/cathepsin inhibitors imbalance remained unchanged and similar (∼2-fold) in the Ps+ and Ps− groups (p<0.001), which correlated with the breakdown of their circulating cystatin-like inhibitors (kininogens). Procathepsins, which may be activated autocatalytically, are a potential proteolytic reservoir. Immunoblotting and active-site labeling identified the double-chain cathepsin B, the major cathepsin in CF sputum, as the main molecular form in both Ps+ and Ps− samples, despite the possible release of the ∼31 kDa single-chain form from procathepsin B by sputum elastase. Thus, the hydrolytic activity of cysteine cathepsins was not correlated with bacterial colonization, indicating that cathepsins, unlike human neutrophil elastase, are not suitable markers of P. aeruginosa infection

VizieR Online Data Catalog: Radial velocity curve of HD 202206 (Couetdic+, 2010)

VizieR On-line Data Catalog: J/A+A/519/A10We consider each inclination and one of the longitudes of ascending node as free parameters. For any chosen triplet of these parameters, we compute a new fit. Then we study the long-term stability in a small (in terms of O-C) neighborhood using Laskar's frequency map analysis. We also introduce a numerical method based on frequency analysis to determine the center of libration mode inside a mean motion resonance

VizieR Online Data Catalog: Radial velocity curve of HD 202206 (Couetdic+, 2010)

VizieR On-line Data Catalog: J/A+A/519/A10We consider each inclination and one of the longitudes of ascending node as free parameters. For any chosen triplet of these parameters, we compute a new fit. Then we study the long-term stability in a small (in terms of O-C) neighborhood using Laskar's frequency map analysis. We also introduce a numerical method based on frequency analysis to determine the center of libration mode inside a mean motion resonance

Leptospirosis in Franche-Comté (FRANCE): clinical, biological, and therapeutic data.

International audienceOBJECTIVES AND METHOD: We report the patient data in 77 cases of leptospirosis confirmed by PCR and/or serology (micro-agglutination), observed between 1994 and 2008 at the Besançon teaching hospital. Our aim was to compare the epidemiological, clinical, biological, and therapeutic characteristics of leptospirosis in the Franche-Comté region, to those reported in other regions. RESULTS: The median age was 42years and 95% were male patients. Leptospirosis acquisition was likely related to aquatic leisure activities (50.6%), professional exposure (28.6%), building maintenance works (11.7%), or unknown (9.1%). Forty-eight cases were uncomplicated and 29 were severe presentations of leptospirosis. Among severe cases, eight patients had to be managed in an intensive care unit, and one patient died. L. grippotyphosa and L. icterohaemorrhagiae were the main serogroups involved. Age above 50years and serogroup L. icterohaemorrhagiae were positively associated with clinical severity. The outcome was favorable for 15 patients treated with ceftriaxone for less than 7days. CONCLUSIONS: We recommended conducting clinical trials aiming at validating short courses of ceftriaxone to treat leptospirosis