We present radial-velocity measurements for three solar-type stars (HD 127506, HD 174457 and HD 185414) hosting low-mass companions. The measurements were obtained with the ELODIE echelle spectrograph mounted on the 1.93–m telescope at Observatoire de Haute–Provence (CNRS, France) within the frame of the OHP-ELODIE Planet Search Programme. The inferred minimum masses of the detected companions are in the substellar mass range. Combining ELODIE radial-velocity data and HIPPARCOS astrometric data, the inclination angles of the orbital planes of HD 127506 and HD 174457 have been derived providing us with the de-projected masses of the companions: m 2 = 44MJup for the companion of HD 127506 and m 2= 0.13M⊙ for the companion of HD 174457. Moreover, using adaptive optics measurements, we show that HD 174457 is probably a (F8V + M7V + M3-4V) triple system. To date, only a minimal orbital solution is available for HD 185414.

Since the discovery of 51 Peg by Mayor & Queloz (1995) about 50 extra-solar planets have been discovered by means of the Doppler technique, and much more will follow. In future the goal will be to detect even lighter planets and/or planets with longer orbital periods, which may induce changes of only few m/s on the radial velocity of their parent star. Therefore very high performance instruments will be required. In view of the realization of HARPS (Pepe et al. 2000), the high-accuracy RV spectrograph for the ESO 3.6-m telescope dedicated to extra-solar planet search, we are investigating the accuracy limits and possible error sources. First results are presented in this paper.

We report the discovery of an extrasolar planetary system with two Saturnian planets around the star HD 83443. The new planetary system is unusual by more than one aspect, as it contains two very low–mass gaseous giant planets, both on very tight orbits. Among the planets detected so far, the inner planet has the smallest semi–major axis (0.038 AU) and period (2.985 days) whereas the outer planet is the lightest one with m2 sin i = 0.53 MSat. A preliminary dynamical study confirms the stability of the system.

Gilliland et al. (2000) have reported HST photometric observations of 34000 stars in the globular cluster 47 Tuc, showing an absence of close-in giant planets in that cluster relative to their frequency in the solar neighborhood. Here we describe the methods of time-series analysis that were used to search the 47 Tuc data for transits by giant extrasolar planets, and the means by which these methods were validated.

We present radial-velocity data measurements for 4 solar-type stars (HD 6434, HD 19994, HD 92788 and HD 121504) harboring new detected planetary companions. The measurements were obtained with the CORALIE echelle spectrograph mounted on the 1.2–m “Leonard Euler” Swiss telescope at ESO–LaSilla Observatory (Chile). The minimum masses inferred for the planets are m 2 sin i = 0.48, 2.0, 3.81 and 0.89MJup, respectively.

The new Hipparcos parallax data for local subdwarfs allow a much more reliable determination of the distance to globular clusters (by direct sequence fitting) than was previously possible. Earlier studies (Reid 1997, Gratton et al. 1997) have reported larger distances than expected, especially for the most metal-poor clusters, implying much younger ages. In our study of Hipparcos subdwarfs applied to M92 — representative of the oldest, most metal-poor clusters — we find however a distance only slightly in excess of previous expectations. We show, using Monte Carlo simulations, that most of the difference may be explained by our more detailed treatment of the Lutz-Kelker and selection biases. With up-to-date stellar evolution models, we derive a minimum age of 13 Gyr for the Universe. This value, although lower than previous estimates, still imposes a rather strict upper limit to Ho in the context of standard cosmological models.

The maximum age of galactic globular clusters provides the best observational constraint on the minimum age of the Universe. One of the main “missing link” in the globular cluster age determination has been the lack of a precise calibration, with local subdwarfs, of the position of the subdwarf sequence at different [Fe/H].

Hipparcos data may change this situation. As many precise parallaxes become available for local subdwarfs, the distance to globular clusters can be estimated directly from ZAMS fitting to the subdwarf locus. The ages can then be inferred from the turnoff luminosity (a robust prediction of stellar evolution models), rather than using secondary indicators such as Horizontal-Branch position, or indicators depending on the uncertain colour scale such as turnoff colour.

Combining Hipparcos parallaxes with [Fe/H] values determined with the CORAVEL spectrometer, we are studying the position of the subdwarfs in the Colour-Magnitude Diagram from a sample of more than 900 subdwarf candidates. Preliminary results are presented here. It is shown that the distances of many subdwarfs had been underestimated in previous studies, mainly because a large fraction of them is in fact evolved off the main sequence into the turnoff or the subgiant branch.

Long-term radial-velocity surveys of G, K and M dwarfs of the solar neighbourhood are presented. The inferred orbital elements are discussed, focusing on the (e, log P) diagram, the mass-ratio and secondary mass distributions, and on the binary frequency of the studied samples. The proportion of companions to M dwarfs is found to be not significantly different from the binary frequency among G- and K-dwarf primaries. The mass function of stellar and planetary companions to solar-type stars strongly suggests different formation and evolution mechanisms for the two populations. Finally, beautiful mass-luminosity relations are obtained from low-mass binaries with high-precision radial-velocity measurements and adaptive optics visual data.

Professor Colomb resigned as President of the Commission because of pressing demands of work. The Organizing Committee appointed Stuart Bowyer (Vice President) as Acting President.

The Commission has proposed changing its name to “Bioastronomy: Search for Extrasolar Planets and Extraterrestial Life” to reflect our long-standing involvement in the search for extrasolar planets. The name change is pending approval of the IAU.

A group of faint, remote Cepheids in the outer disc of the Galaxy has been observed in spectroscopy and photometry. These Cepheids are used as tracers to measure the rotation curve of the disc beyond R=11 kpc, and to study the metallicity gradient in the outer disc.

The parallax data gathered by Hipparcos for field subdwarfs allow a muchmore precise determination of globular cluster distances by direct sequencefitting than was previously possible. We determined the distance and age ofthe old, representative globular cluster M92 from a set of more than 500 subdwarf candidates with Hipparcos parallaxes. Precise [Fe/H] values were derived using the equivalent width of the CORAVEL cross-correlation function.

Our best estimate of the distance of M92 is (m — M)v = 14.67 ± 0.08 (including binaries with a statistical correction) or (m — M)v = 14.74 ± 0.08 (classic treatment, i.e. excluding binaries). The agreement of the cluster sequence with the position of extreme metal-poor field subdwarfs is remarkable [figure, left]. The distance found is slightly higher than previously thought. The corresponding ages, derived by comparing the luminosity of the turnoff and subgiant-branchstars with up-to-date evolution models [figure, right], are 14±1.2 Gyr or 13±1.2 Gyr respectively, implying a minimum age of 13 Gyr for the Universe.

Other authors have claimed that larger distances, and smaller ages, resulted from Hipparcos subdwarf parallaxes. Although there are some differences in the data sets used by each author, the main difference resides in the treatment of systematic and selection biases. We have examined at some length the biases affecting the determination of the mean luminosity of a set of subdwarfs selected in the usual way. By means of Monte Carlo simulations, we show that selection biases act in a direction opposite to the classic Lutz-Kelker bias affecting parallax data, and that they can be dominant. The biases introduced are of the order of 0.1 mag.

It is pointed out that, now that the whole Hipparcos catalogue is available, we shall be able to greatly reduce the systematic biases by refining the fitting procedure. Firstly, by imposing no [Fe/H] limits and fitting the subdwarf locus for all [Fe/H] values at the same time. Secondly, by imposing no parallax error limit and fitting the data in parallax space instead of magnitude space (comparing observed parallaxes directly with parallaxes predicted from the models).

This study aimed to analyse the existence of an association between social class (categorized by type of occupation) and the occurrence of A(H1N1)pmd09 infection and hospitalization for two seasons (2009–2010 and 2010–2011). This multicentre study compared ambulatory A(H1N1)pmd09 confirmed cases with ambulatory controls to measure risk of infection, and with hospitalized A(H1N1)pmd09 confirmed cases to asses hospitalization risk. Study variables were: age, marital status, tobacco and alcohol use, pregnancy, chronic obstructive pulmonary disease, chronic respiratory failure, cardiovascular disease, diabetes, chronic liver disease, body mass index >40, systemic corticosteroid treatment and influenza vaccination status. Occupation was registered literally and coded into manual and non-manual worker occupational social class groups. A conditional logistic regression analysis was performed. There were 720 hospitalized cases, 996 ambulatory cases and 1062 ambulatory controls included in the study. No relationship between occupational social class and A(H1N1)pmd09 infection was found [adjusted odds ratio (aOR) 0·97, 95% confidence interval (CI) 0·74–1·27], but an association (aOR 1·53, 95% CI 1·01–2·31) between occupational class and hospitalization for A(H1N1)pmd09 was observed. Influenza vaccination was a protective factor for A(H1N1)pmd09 infection (aOR 0·41, 95% CI 0·23–0·73) but not for hospitalization. We conclude that manual workers have the highest risk of hospitalization when infected by influenza than other occupations but they do not have a different probability of being infected by influenza.

We report on a new survey of metallicities, ages, and Galactic orbits for a complete, magnitude-limited, and kinematically unbiased all-sky sample of 16 682 nearby F- and G-dwarfs. Our ∼ 63 000 new, accurate radial velocities for nearly 13 500 of the stars, combined with Hipparcos parallaxes and Tycho-2 proper motions, complete the kinematic data for 14 139 stars and allow us to identify most of the binary stars in the sample. Isochrone ages have been determined whenever reliable results are possible, with particular attention to realistic error estimates.

Among the basic properties of the Galactic disk that can be reinvestigated from our data are the metallicity distribution of G-dwarfs and the age–metallicity and age–velocity relations of the solar neighbourhood. We confirm the lack of metal-poor G-dwarfs relative to classical model predictions (the 'G-dwarf problem'), the near-constancy of the mean metallicity since the formation of the thin disk, and the appearance of the kinematic signature of the thick disk ∼ 10 Gyr ago.

The partial specific enthalpy and the partial specific entropy for the water uptake of two bentonites was investigated by means of the water vapor adsorption-desorption isotherms and the heat of immersion with liquid water. From these experiments, and as confirmed by X-ray measurements, it is evident that the interlayer water shows a high degree of order. Calculations of the swelling pressure from the adsorption isotherms show good agreement with measured swelling pressures.

The uptake of liquid water by the compacted bentonites under conditions of restrained swelling can be described as a non-steady state diffusion with constant surface concentration. The water uptake of two bentonites in their natural sodium and calcium forms has been investigated. The measurements were carried out in a swelling pressure apparatus with water supply from one or both sides, and in a device modelling the repository conditions with radial water supply. In this modelling experiment, the water uptake was measured and the enclosed air determined. In addition, the swelling pressure was observed and compared to earlier test results.

The meeting was opened by Ted Bowell, president, at 11 am. The 2006 Division III meetings were reviewed by Guy Consolmagno, secretary; as the minutes of those meetings have already been published, they were assumed to be approved.

Due to their high vsini, early-type main-sequence stars have been considered as unsuitable targets for radial-velocity surveys. Knowing about the presence of planets around those stars is however a key issue to understand the impact of the mass of the central star on the way planets form and evolve. We developped in recent years a method that allows to search for planets around those stars and started radial-velocity surveys focused on these targets. We report here some results obtained so far in terms of performances and detection.

Division III's activities focus on a broad range of astronomical research on bodies in the solar system (excluding the Sun), on extrasolar planets, and on the search for life in the Universe.