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See detailFirst Magnetic Field Models for Recently Discovered Magnetic β Cephei and Slowly Pulsating B Stars
Hubrig, S.; Schöller, M.; Ilyin, I. et al

in Progress in Solar/Stellar Physics with Helio- and Asteroseismology (2012, September 01)

Despite of the importance of magnetic fields for the full understanding of the properties of pulsating β Cephei and slowly pulsating B (SPB) stars, these fields have scarcely been studied over the ... [more ▼]

Despite of the importance of magnetic fields for the full understanding of the properties of pulsating β Cephei and slowly pulsating B (SPB) stars, these fields have scarcely been studied over the rotation cycle until now. During the past two years we have obtained multi-epoch polarimetric spectra of several β Cephei and SPB stars with FORS 2 at the Very Large Telescope and SOFIN at the Nordic Optical Telescope to search for a rotation period and to constrain the geometry of the magnetic field. The rotation periods and magnetic field geometries were determined for three β Cephei stars, ℰ[SUP]1[/SUP] CMa, 15 CMa, and V1449 Aql, the candidate β Cephei star α Pyx, and the SPB star 33 Eri. [less ▲]

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See detailFirst Magnetic Field Models for Recently Discovered Magnetic β Cephei and Slowly Pulsating B Stars
Hubrig, S.; Ilyin, Ilya; Schöller, Markus et al

in Astrophysical Journal Letters (2011), 726

In spite of recent detections of magnetic fields in a number of β Cephei and slowly pulsating B (SPB) stars, their impact on stellar rotation, pulsations, and element diffusion has not yet been ... [more ▼]

In spite of recent detections of magnetic fields in a number of β Cephei and slowly pulsating B (SPB) stars, their impact on stellar rotation, pulsations, and element diffusion has not yet been sufficiently studied. The reason for this is the lack of knowledge of rotation periods, the magnetic field strength distribution and temporal variability, and the field geometry. New longitudinal field measurements of four β Cephei and candidate β Cephei stars, and two SPB stars were acquired with FORS 2 at the Very Large Telescope. These measurements allowed us to carry out a search for rotation periods and to constrain the magnetic field geometry for four stars in our sample. Based on observations obtained at the European Southern Observatory (ESO programme 084.D-0230(A)). [less ▲]

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See detailFirst man in the eastern Finland : an Early Mesolithic inland site with a red-ochre grave in Joensuu Rahakangas
Pesonen, Petro; Hertell, Esa; Nyholm, Mikael et al

Poster (2010)

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See detailFirst manufactured diamond AGPM vector vortex for the L- and N-bands: metrology and expected performances
Delacroix, Christian ULg; Forsberg, Pontus; Karlsson, Mikael et al

Conference (2010, October 28)

The AGPM (Annular Groove Phase Mask, Mawet et al. 2005) is an optical vectorial vortex coronagraph (or vector vortex) synthesized by a circular subwavelength grating, that is a grating with a period ... [more ▼]

The AGPM (Annular Groove Phase Mask, Mawet et al. 2005) is an optical vectorial vortex coronagraph (or vector vortex) synthesized by a circular subwavelength grating, that is a grating with a period smaller than λ/n (λ being the observed wavelength and n the refractive index of the grating substrate). Since it is a phase mask, it allows to reach a high contrast with a small working angle. Moreover, its subwavelength structure provides a good achromatization over wide spectral bands. Recently, we have manufactured and measured our first N-band prototypes that allowed us to validate the reproducibility of the microfabrication process. Here, we present newly produced mid-IR diamond AGPMs in the N-band (~10 µm), and in the most wanted L-band (~3.5 µm). We first give an extrapolation of the expected coronagraph performances. We then present the manufacturing and measurement results, using diamond-optimized microfabrication techniques such as nano-imprint lithography (NIL) and reactive ion etching (RIE). Finally, the subwavelength grating profile metrology combines surface metrology (scanning electron microscopy, atomic force microscopy, white light interferometry) with diffractometry on an optical polarimetric bench and cross correlation with theoretical simulations using rigorous coupled wave analysis (RCWA). [less ▲]

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See detailA First Measurement Look at the Deployment and Evolution of the Locator/ID Separation Protocol
Saucez, Damien; Iannone, Luigi; Donnet, Benoît ULg

in Computer Communication Review (2013), 43(1), 37-43

During the last decade, we have seen the rise of discussions regarding the emergence of a Future Internet. One of the proposed approaches leverages on the separation of the identifier and the locator ... [more ▼]

During the last decade, we have seen the rise of discussions regarding the emergence of a Future Internet. One of the proposed approaches leverages on the separation of the identifier and the locator roles of IP addresses, leading to the LISP (Locator/Identifier Separation Protocol) protocol, currently under development at the IETF (Internet Engineering Task Force). Up to now, researches made on LISP have been rather theoretical, i.e., based on simulations/emulations often using Internet traffic traces. There is no work in the literature attempting to assess the state of its deployment and how this has evolved in recent years. This paper aims at bridging this gap by presenting a first measurement study on the existing worldwide LISP network (lisp4.net). Early results indicate that there is a steady growth of the LISP network but also that network manageability might receive a higher priority than performance in a large scale deployment. [less ▲]

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See detailFirst measurements of the HCFC-142b trend from atmospheric chemistry experiment (ACE) solar occultation spectra
Rinsland, Curtis P; Chiou, Linda; Boone, Chris et al

in Journal of Quantitative Spectroscopy & Radiative Transfer (2009), 110(18), 2127-2134

The first measurement of the HCFC-142b (CH3CClF2) trend near the tropopause has been derived from volume mixing ratio (VMR) measurements at northern and southern hemisphere mid-latitudes for the 2004-2008 ... [more ▼]

The first measurement of the HCFC-142b (CH3CClF2) trend near the tropopause has been derived from volume mixing ratio (VMR) measurements at northern and southern hemisphere mid-latitudes for the 2004-2008 time period from spaceborne solar occultation observations recorded at 0.02 cm(-1) resolution with the ACE (atmospheric chemistry experiment) Fourier transform spectrometer. The HCFC-142b molecule is currently the third most abundant HCFC (hydrochlorofluorocarbon) in the atmosphere and ACE measurements over this time span show a continuous rise in its volume mixing ratio. Monthly average measurements at northern and southern hemisphere mid-latitudes have similar increase rates that are consistent with surface trend measurements for a similar time span. A mean northern hemisphere profile for the time span shows a near constant VMR at 8-20 km altitude range, consistent on average for the same time span with in situ results. The nearly constant vertical VMR profile also agrees with model predictions of a long lifetime in the lower atmosphere. (c) 2009 Elsevier Ltd. All rights reserved. [less ▲]

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See detailFirst mesocosm experiments to study the impacts of ocean acidification on plankton communities in the NW Mediterranean Sea (MedSeA project)
Gazeau, F; Sallon, A; Maugendre, L et al

in Estuarine Coastal & Shelf Science (2016)

There is a growing international interest in studying the effects of ocean acidification on plankton communities that play a major role in the global carbon cycle and in the consumption of atmospheric CO2 ... [more ▼]

There is a growing international interest in studying the effects of ocean acidification on plankton communities that play a major role in the global carbon cycle and in the consumption of atmospheric CO2 via the so-called biological pump. Recently, several mesocosm experiments reported on the effect of ocean acidification on marine plankton communities, although the majority were performed in eutro- phic conditions or following nutrient addition. The objective of the present study was to perform two mesocosm experiments in the oligo- to meso-trophic Northwestern Mediterranean Sea during two seasons with contrasting environmental conditions: in summer 2012 in the Bay of Calvi (Corsica, France) and in winter 2013 in the Bay of Villefranche (France). This paper describes the objectives of these ex- periments, the study sites, the experimental set-up and the environmental and experimental conditions during the two experiments. The 20-day experiment in the Bay of Calvi was undoubtedly representative of summer conditions in the Northwestern Mediterranean Sea with low nutrient and chlorophyll a concentrations, warm waters and high surface solar irradiance. In contrast, the winter experiment, which was reduced to 12 days because of bad weather conditions, failed to reproduce the mesotrophic con- ditions typical of the wintertime in this area. Indeed, a rapid increase in phytoplankton biomass during the acidification phase led to a strong decrease in nitrate concentrations and an unrealistic N and P co- limitation at this period of the year. An overview of the 11 other papers related to this study and pub- lished in this special issue is provided. [less ▲]

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See detailFirst Molecular Evidence of Potentially Zoonotic Babesia microti and Babesia sp. EU1 in Ixodes ricinus Ticks in Belgium
Lempereur, Laetitia ULg; De Cat, Ann; Caron, Yannick ULg et al

in Vector Borne & Zoonotic Diseases (2011), 11(2), 125-30

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See detailFirst monitoring results of three straw bale buildings in Belgium
Evrard, Arnaud; Dubois, Samuel ULg; Louis, Arnaud et al

Conference (2014, December 13)

Straw bale use in buildings may be an interesting way to decrease our energy needs and our impact on environment. The present paper describes an experimental set up to monitor three straw bale buildings ... [more ▼]

Straw bale use in buildings may be an interesting way to decrease our energy needs and our impact on environment. The present paper describes an experimental set up to monitor three straw bale buildings recently built in Belgium. For each building, results on temperature and relative humidity, inside and outside, are analyzed, as well as internal evolution of temperature and humidity distribution in the walls. The first building is an office building where two finishing are compared. Measurements also provide additional data on CO2 levels and electric consumption. The two other buildings are dwellings where live one single family. In the first one, a wall in the bedroom and a retaining wall are analyzed. In the second one, a wall in the bedroom and a wall in the bathroom are analyzed. Their hygrothermal behavior is discussed based on simulation results obtained with WUFI Pro and WUFI Plus software. The criterion for the validation of wall behavior is based on water content distribution through the walls. The paper confirms the great potential of this type of building technology and helps to identify how to assess and validate their effective hygrothermal behavior. [less ▲]

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See detailFirst nationwide survey on cardiovascular risk factors in Grand-Duchy of Luxembourg (ORISCAV-LUX)
Alkerwi, A; Sauvageot, N; Donneau, Anne-Françoise ULg et al

Poster (2010)

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See detailFirst nationwide survey on cardiovascular risk factors in Grand-Duchy of Luxembourg (ORISCAV-LUX).
Alkerwi, Ala'a; Sauvageot, Nicolas; Donneau, Anne-Françoise ULg et al

in BMC Public Health (2010), 10

BACKGROUND: The ORISCAV-LUX study is the first baseline survey of an on-going cardiovascular health monitoring programme in Grand-Duchy of Luxembourg. The main objectives of the present manuscript were 1 ... [more ▼]

BACKGROUND: The ORISCAV-LUX study is the first baseline survey of an on-going cardiovascular health monitoring programme in Grand-Duchy of Luxembourg. The main objectives of the present manuscript were 1) to describe the study design and conduct, and 2) to present the salient outcomes of the study, in particular the prevalence of the potentially modifiable and treatable cardiovascular disease risk factors in the adult population residing in Luxembourg. METHOD: ORISCAV-LUX is a cross-sectional study based on a random sample of 4496 subjects, stratified by gender, age categories and district, drawn from the national insurance registry of 18-69 years aged Luxembourg residents, assuming a response rate of 30% and a proportion of 5% of institutionalized subjects in each stratum. The cardiovascular health status was assessed by means of a self-administered questionnaire, clinical and anthropometric measures, as well as by blood, urine and hair examinations. The potentially modifiable and treatable risk factors studied included smoking, hypertension, dyslipidemia, diabetes mellitus, and obesity. Both univariate and multivariate statistical analyses used weighted methods to account for the stratified sampling scheme. RESULTS: A total of 1432 subjects took part in the survey, yielding a participation rate of 32.2%. This figure is higher than the minimal sample size of 1285 subjects as estimated by power calculation. The most predominant cardiovascular risk factors were dyslipidemia (69.9%), hypertension (34.5%), smoking (22.3%), and obesity (20.9%), while diabetes amounted 4.4%. All prevalence rates increased with age (except smoking) with marked gender differences (except diabetes). There was a significant difference in the prevalence of hypertension and of lipid disorders by geographic region of birth. The proportion of subjects cumulating two or more cardiovascular risk factors increased remarkably with age and was more predominant in men than in women (P<0.0001). Only 14.7% of men and 23.1% of women were free of any cardiovascular risk factor. High prevalence of non-treated CVRF, notably for hypertension and dyslipidemia, were observed in the study population. CONCLUSION: The population-based ORISCAV-LUX survey revealed a high prevalence of potentially modifiable and treatable cardiovascular risk factors among apparently healthy subjects; significant gender and age-specific differences were seen not only for single but also for combined risk factors. From a public health perspective, these preliminary findings stress the urgent need for early routine health examinations, preventive interventions and lifestyle behavioural changes, even in young asymptomatic adults, to decrease cardiovascular morbidity and mortality in Luxembourg. [less ▲]

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See detailFirst New Solar Models With Opas Opacity Tables
Le Pennec, Maëlle; Turck-Chièze, Sylvaine; Salmon, Sébastien ULg et al

in Astrophysical Journal Letters (2015), 813(2), 42

Stellar seismology appears more and more as a powerful tool for a better determination of the fundamental properties of solar-type stars. However, the particular case of the Sun is still challenging. For ... [more ▼]

Stellar seismology appears more and more as a powerful tool for a better determination of the fundamental properties of solar-type stars. However, the particular case of the Sun is still challenging. For about a decade now, the helioseismic sound-speed determination has continued to disagree with the standard solar model (SSM) prediction, questioning the reliability of this model. One of the sources of uncertainty could be in the treatment of the transport of radiation from the solar core to the surface. In this Letter, we use the new OPAS opacity tables, recently available for solar modeling, to address this issue. We discuss first the peculiarities of these tables, then we quantify their impact on the solar sound-speed and density profiles using the reduced OPAS tables taken on the grids of the OPAL ones. We use the two evolution codes, Modules for Experiments in Stellar Astrophysics and Code Liégeois d'Evolution Stellaire, that led to similar conclusions in the solar radiative zone. In comparison to commonly used OPAL opacity tables, the new solar models are computed for the most recent photospheric composition with OPAS tables and present improvements to the location of the base of the convective zone and to the description of the solar radiative zone in comparison to the helioseismic observations, even if the differences in the Rosseland mean opacity do not exceed 6%. We finally carry out a comparison to a solar model computed with the OP opacity tables. [less ▲]

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See detailFirst observations of anthropogenic underwater noise in a large multi-use lake
Bolgan, Marta ULg; Chorazyczewska, Emilia; Winfield, Ian J. et al

in Journal of Limnology (2016)

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See detailFirst occurrence of the lungfish Sagenodus (Dipnoi, Sarcopterygii) from the Carboniferous Lagerstätte of Montceau-les-Mines, France
Olive, Sébastien ULg; Clément, Gaël; Pouillon, Jean-Marc

in Ichthyolith Issues (2011)

New material of the dipnoan genus Sagenodus is described from the Carboniferous of the Barrat quarry (Blanzy-Creuzot coal basin, Montceau-les-Mines, France). This is the first occurrence of this lungfish ... [more ▼]

New material of the dipnoan genus Sagenodus is described from the Carboniferous of the Barrat quarry (Blanzy-Creuzot coal basin, Montceau-les-Mines, France). This is the first occurrence of this lungfish in France, which enlarges its distribution within Europe (Fritsch, 1888; Schultze, 1993; Watson and Gill, 1923). This material is Stephanian B in age, the previously established geological range of this Euramerican (Schultze and Chorn, 1997) genus. Remains consist of skull, lower jaw and shoulder girdle elements, closely set together with many ribs. This material, considered as belonging to a single disarticulated specimen, presents affinities with the material of Sagenodus sp. from Germany (Schultze, 1993) and appears significantly different to all other known Sagenodus species. However this new material can only be attributed to Sagenodus sp. because of its incompleteness. Montceau-les-Mines is interpreted as a freshwater environment deposit and the presence of Sagenodus in this locality confirms that most of the localities of Sagenodus are freshwater deposits. The strong affinities, existing between the material from France and Germany, indicate that there were solid hydrographic links between both basins during the Stephanian B–Upper Rotliegend period. [less ▲]

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See detailFirst occurrence of the lungfish Sagenodus (Dipnoi, Sarcopterygii) from the Carboniferous Lagerstätte of Montceau-les-Mines, France
Olive, Sébastien ULg; Clément, Gaël; Pouillon, Jean-Marc

in Journal of Vertebrate Paleontology (2012), 32(2), 285-295

New material of the dipnoan genus Sagenodus is described from the Carboniferous Lagerstätte of Montceau-les-Mines, Massif Central, France. This is the first occurrence of this lungfish in France, thus ... [more ▼]

New material of the dipnoan genus Sagenodus is described from the Carboniferous Lagerstätte of Montceau-les-Mines, Massif Central, France. This is the first occurrence of this lungfish in France, thus enlarging its worldwide distribution; and the first occurrence of a lungfish in Montceau-les-Mines, thus increasing the vertebrate taxa list of this Lagerstätte. This material is Stephanian B in age, the previously established geological range of this Euramerican genus. Remains consist of skull, lower jaw, operculum, and shoulder girdle elements closely set together with several ribs. This material, here considered as belonging to a single disarticulated specimen, shows strong affinities with the material of Sagenodus sp. from Germany and appears significantly different from all other known species of Sagenodus by the shape and ridge pattern of the upper tooth plate. However, this new material can only be attributed to Sagenodus sp. due to its incompleteness. In the literature, Montceau-les-Mines is either interpreted as a freshwater environment or as a coastal marine to marine-influenced environment. As Sagenodus is a euryhaline genus; its presence in this locality does not bring arguments to one or the other assumption. The strong affinities, existing between the material from France and Germany, indicate that there were solid hydrographic links between both basins during the Stephanian B–Upper Rotliegend period. [less ▲]

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See detailFirst on-sky results with ARGOS at LBT
Orban De Xivry, Gilles ULg; Rabien, Sebastian; Busoni, Lorenzo et al

in First on-sky results with ARGOS at LBT (2016, July)

One year and an half after ARGOS first light, the Large Binocular Telescope (LBT) laser guided ground-layer adaptive optics (GLAO) system has been operated on both sides of the LBT. The system fulfills ... [more ▼]

One year and an half after ARGOS first light, the Large Binocular Telescope (LBT) laser guided ground-layer adaptive optics (GLAO) system has been operated on both sides of the LBT. The system fulfills the GLAO promise and typically delivers an improvement by a factor of 2 in FWHM over the 4'×4' field of view of both Luci instruments, the two near-infrared imagers and multi-object spectrographs. In this paper, we report on the first on-sky results and analyze the performances based on the data collected so far. We also discuss adaptive optics procedures and the joint operations with Luci for science observations. [less ▲]

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See detailThe first orbital solution for the massive colliding-wind binary HD 93162 ( WR 25)
Gamen, R.; Gosset, Eric ULg; Morrell, N. et al

in Astronomy and Astrophysics (2006), 460(3), 777-782

Context. Since the discovery, with the EINSTEIN satellite, of strong X-ray emission associated with HD 93162 (equivalent to WR 25), this object has been predicted to be a colliding-wind binary system ... [more ▼]

Context. Since the discovery, with the EINSTEIN satellite, of strong X-ray emission associated with HD 93162 (equivalent to WR 25), this object has been predicted to be a colliding-wind binary system. However, radial-velocity variations that would prove the suspected binary nature have yet to be found. Aims. We spectroscopically monitored this object to investigate its possible variability to address this discordance. Methods. We compiled the largest available radial-velocity data set for this star to look for variations that might be due to binary motion. We derived radial velocities from spectroscopic data acquired mainly between 1994 and 2006, and searched these radial velocities for periodicities using different numerical methods. Results. For the first time, periodic radial-velocity variations are detected. Our analysis definitively shows that the Wolf-Rayet star WR 25 is an eccentric binary system with a probable period of about 208 days. [less ▲]

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See detailThe first orbital solution for the massive colliding-wind binary HD 93162 (=WR 25)
Gamen, R.; Gosset, Eric ULg; Morrell, N. I. et al

in Revista Mexicana de Astronomia y Astrofisica Conference Series (2008, August 01)

Since the discovery, with EINSTEIN, of strong X-ray emission associated with HD 93162, this object was recurrently predicted by some authors to be a colliding-wind binary system. However, radial-velocity ... [more ▼]

Since the discovery, with EINSTEIN, of strong X-ray emission associated with HD 93162, this object was recurrently predicted by some authors to be a colliding-wind binary system. However, radial-velocity variations that would prove the suspected binary nature have never been found so far. We spectroscopically monitored this object in order to investigate its possible variability and to provide an answer to the above-mentioned discordance. We derived radial velocities from spectroscopic data acquired mainly between 1994 and 2006, and searched for periodicities. For the first time, periodic radial-velocity variations are detected. Our analysis definitively shows that the Wolf-Rayet star WR 25 is actually an eccentric binary system with a probable period of about 208 days. [less ▲]

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See detailFirst Orbital Solution for the Non-thermal Emitter Cyg OB2 No. 9
Nazé, Yaël ULg; Damerdji, Yassine ULg; Rauw, Grégor ULg et al

in Astrophysical Journal (2010), 719

After the first detection of its binary nature, the spectroscopic monitoring of the non-thermal radio emitter Cyg OB2 No. 9 (P = 2.4 yr) has continued, doubling the number of available spectra of the star ... [more ▼]

After the first detection of its binary nature, the spectroscopic monitoring of the non-thermal radio emitter Cyg OB2 No. 9 (P = 2.4 yr) has continued, doubling the number of available spectra of the star. Since the discovery paper of 2008, a second periastron passage has occurred in 2009 February. Using a variety of techniques, the radial velocities could be estimated and a first, preliminary orbital solution was derived from the He I 5876 line. The mass ratio appears close to unity and the eccentricity is large, i.e., 0.7-0.75. X-ray data from 2004 and 2007 are also analyzed in quest of peculiarities linked to binarity. The observations reveal neither large overluminosity nor strong hardness, but it must be noted that the high-energy data were taken after the periastron passage, at a time where colliding wind emission may be low. Some unusual X-ray variability is however detected, with a 10% flux decrease between 2004 and 2007. To clarify their origin and find a more obvious signature of the wind-wind collision, additional data, taken at periastron and close to it, are needed. Based on observations collected at the Haute-Provence Observatory and with XMM-Newton, an ESA Science Mission with instruments and contributions directly funded by ESA Member States and the USA (NASA). [less ▲]

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See detailA first orbital solution for the non-thermal radio emitter Cyg OB2 #9
Nazé, Yaël ULg; Damerdji, Yassine ULg; Rauw, Grégor ULg et al

in Bulletin de la Société Royale des Sciences de Liège (2011), 80

We reported in 2008 the first detection of the binary nature of Cyg OB2 #9. Since then, we have continued our spectroscopic monitoring of this object, doubling the number of available spectra of the star ... [more ▼]

We reported in 2008 the first detection of the binary nature of Cyg OB2 #9. Since then, we have continued our spectroscopic monitoring of this object, doubling the number of available spectra of the star while covering a second periastron passage. Using a variety of techniques, the radial velocities were estimated and a first, preliminary orbital solution was derived (P=2.4 yrs). The mass ratio appears close to unity and the eccentricity is large, 0.7-0.75. [less ▲]

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