References of "Briquet, Maryline"      in Complete repository Arts & humanities   Archaeology   Art & art history   Classical & oriental studies   History   Languages & linguistics   Literature   Performing arts   Philosophy & ethics   Religion & theology   Multidisciplinary, general & others Business & economic sciences   Accounting & auditing   Production, distribution & supply chain management   Finance   General management & organizational theory   Human resources management   Management information systems   Marketing   Strategy & innovation   Quantitative methods in economics & management   General economics & history of economic thought   International economics   Macroeconomics & monetary economics   Microeconomics   Economic systems & public economics   Social economics   Special economic topics (health, labor, transportation…)   Multidisciplinary, general & others Engineering, computing & technology   Aerospace & aeronautics engineering   Architecture   Chemical engineering   Civil engineering   Computer science   Electrical & electronics engineering   Energy   Geological, petroleum & mining engineering   Materials science & engineering   Mechanical engineering   Multidisciplinary, general & others Human health sciences   Alternative medicine   Anesthesia & intensive care   Cardiovascular & respiratory systems   Dentistry & oral medicine   Dermatology   Endocrinology, metabolism & nutrition   Forensic medicine   Gastroenterology & hepatology   General & internal medicine   Geriatrics   Hematology   Immunology & infectious disease   Laboratory medicine & medical technology   Neurology   Oncology   Ophthalmology   Orthopedics, rehabilitation & sports medicine   Otolaryngology   Pediatrics   Pharmacy, pharmacology & toxicology   Psychiatry   Public health, health care sciences & services   Radiology, nuclear medicine & imaging   Reproductive medicine (gynecology, andrology, obstetrics)   Rheumatology   Surgery   Urology & nephrology   Multidisciplinary, general & others Law, criminology & political science   Civil law   Criminal law & procedure   Criminology   Economic & commercial law   European & international law   Judicial law   Metalaw, Roman law, history of law & comparative law   Political science, public administration & international relations   Public law   Social law   Tax law   Multidisciplinary, general & others Life sciences   Agriculture & agronomy   Anatomy (cytology, histology, embryology...) & physiology   Animal production & animal husbandry   Aquatic sciences & oceanology   Biochemistry, biophysics & molecular biology   Biotechnology   Entomology & pest control   Environmental sciences & ecology   Food science   Genetics & genetic processes   Microbiology   Phytobiology (plant sciences, forestry, mycology...)   Veterinary medicine & animal health   Zoology   Multidisciplinary, general & others Physical, chemical, mathematical & earth Sciences   Chemistry   Earth sciences & physical geography   Mathematics   Physics   Space science, astronomy & astrophysics   Multidisciplinary, general & others Social & behavioral sciences, psychology   Animal psychology, ethology & psychobiology   Anthropology   Communication & mass media   Education & instruction   Human geography & demography   Library & information sciences   Neurosciences & behavior   Regional & inter-regional studies   Social work & social policy   Sociology & social sciences   Social, industrial & organizational psychology   Theoretical & cognitive psychology   Treatment & clinical psychology   Multidisciplinary, general & others     Showing results 1 to 20 of 173 1 2 3 4 5 6     Combined asteroseismology, spectroscopy, and astrometry of the CoRoT B2V target HD 170580Aerts, C.; Pedersen, M. G.; Vermeyen, E. et alin Astronomy and Astrophysics (2019), 624Detailed reference viewed: 21 (1 ULiège) B fields in OB stars (BOB): Concluding the FORS 2 observing campaignSchöller, M.; Hubrig, S.; Fossati, L. et alin Astronomy and Astrophysics (2017), 599Aims. The B fields in OB stars (BOB) Collaboration is based on an ESO Large Programme to study the occurrence rate, properties, and ultimately the origin of magnetic fields in massive stars. Methods. In ... [more ▼]Aims. The B fields in OB stars (BOB) Collaboration is based on an ESO Large Programme to study the occurrence rate, properties, and ultimately the origin of magnetic fields in massive stars. Methods. In the framework of this program, we carried out low-resolution spectropolarimetric observations of a large sample of massive stars using FORS 2 installed at the ESO VLT 8 m telescope. Results. We determined the magnetic field values with two completely independent reduction and analysis pipelines. Our in-depth study of the magnetic field measurements shows that differences between our two pipelines are usually well within 3σ errors. From the 32 observations of 28 OB stars, we were able to monitor the magnetic fields in CPD -57° 3509 and HD 164492C, confirm the magnetic field in HD 54879, and detect a magnetic field in CPD -62° 2124. We obtain a magnetic field detection rate of 6 ± 3% for the full sample of 69 OB stars observed with FORS 2 within the BOB program. For the preselected objects with a v sin i below 60 km s-1, we obtain a magnetic field detection rate of 5 ± 5%. We also discuss X-ray properties and multiplicity of the objects in our FORS 2 sample with respect to the magnetic field detections. © ESO, 2017. [less ▲]Detailed reference viewed: 34 (1 ULiège) Photometric and spectroscopic variability of the B5IIIe star HD 171219Andrade, L.; Janot-Pacheco, E.; Emilio, M. et alin Astronomy and Astrophysics (2017), 603Detailed reference viewed: 19 (0 ULiège) Magnetic characterization of the SPB/$\beta$ Cep hybrid pulsator HD 43317Buysschaert, B.; Neiner, C.; Briquet, Maryline et alin Astronomy and Astrophysics (2017), 605Detailed reference viewed: 24 (0 ULiège) The challenge of measuring magnetic fields in strongly pulsating stars: the case of HD 96446Järvinen, S. P.; Hubrig, S.; Ilyin, I. et alin Monthly Notices of the Royal Astronomical Society (2017), 464Detailed reference viewed: 23 (0 ULiège) Magnetic field geometry and chemical abundance distribution of the He-strong star CPD -57\deg3509Hubrig, S.; Przybilla, N.; Korhonen, H. et alin Monthly Notices of the Royal Astronomical Society (2017), 471Detailed reference viewed: 23 (0 ULiège) The Central Role of FORS1/2 Spectropolarimetric Observations for the Progress of Stellar Magnetism StudiesSchöller, M.; Hubrig, S.; Ilyin, I. et alin Messenger (2016), 163The spectropolarimetric mode of the FOcal Reducer and low dispersion Spectrographs (FORS), which was first implemented in FORS1, and then moved to FORS2 seven years ago, has made it possible to probe the ... [more ▼]The spectropolarimetric mode of the FOcal Reducer and low dispersion Spectrographs (FORS), which was first implemented in FORS1, and then moved to FORS2 seven years ago, has made it possible to probe the presence of magnetic fields in stars of different spectral classes at almost all stages of stellar evolution. While in the early days of FORS1, many of the observations were related to magnetic Ap/Bp stars and their progenitor Herbig Ae/Be stars, recent spectropolarimetric studies with FORS2 have involved more challenging targets, such as massive O- and B-type stars in clusters and in the field, very fast rotating massive stars with magnetospheres, Wolf-Rayet stars and central stars of planetary nebulae. The role of FORS observations for stellar magnetic field measurements is summarised and improvements in the measurement technique are described. [less ▲]Detailed reference viewed: 19 (2 ULiège) Weak magnetic field, solid-envelope rotation, and wave-induced N-enrichment in the SPB star zeta CassiopeiaeBriquet, Maryline ; Neiner, C.; Petit, P. et alin Astronomy and Astrophysics (2016), 587Aims. The main-sequence B-type star zeta Cassiopeiae is known as a N-rich star with a magnetic field discovered with the Musicos spectropolarimeter. We model the magnetic field of the star by means of 82 ... [more ▼]Aims. The main-sequence B-type star zeta Cassiopeiae is known as a N-rich star with a magnetic field discovered with the Musicos spectropolarimeter. We model the magnetic field of the star by means of 82 new spectropolarimetric observations of higher precision to investigate the field strength, topology, and effect. Methods. We gathered data with the Narval spectropolarimeter installed at Télescope Bernard Lyot (TBL; Pic du Midi, France) and applied the least-squares deconvolution technique to measure the circular polarisation of the light emitted from zeta Cas. We used a dipole oblique rotator model to determine the field configuration by fitting the longitudinal field measurements and by synthesizing the measured Stokes V profiles. We also made use of the Zeeman-Doppler imaging technique to map the stellar surface and to deduce the difference in rotation rate between the pole and equator. Results. zeta Cas exhibits a polar field strength B_pol of 100-150 G, which is the weakest polar field observed so far in a massive main-sequence star. Surface differential rotation is ruled out by our observations and the field of zeta Cas is strong enough to enforce rigid internal rotation in the radiative zone according to theory. Thus, the star rotates as a solid body in the envelope. Conclusions. We therefore exclude rotationally-induced mixing as the cause of the surface N-enrichment. We discuss that the transport of chemicals from the core to the surface by internal gravity waves is the most plausible explanation for the nitrogen overabundance at the surface of zeta Cas. [less ▲]Detailed reference viewed: 40 (3 ULiège) The MiMeS survey of magnetism in massive stars: introduction and overviewWade, G. A.; Neiner, C.; Alecian, E. et alin Monthly Notices of the Royal Astronomical Society (2016), 456The MiMeS (Magnetism in Massive Stars) project is a large-scale, high-resolution, sensitive spectropolarimetric investigation of the magnetic properties of O- and early B-type stars. Initiated in 2008 and ... [more ▼]The MiMeS (Magnetism in Massive Stars) project is a large-scale, high-resolution, sensitive spectropolarimetric investigation of the magnetic properties of O- and early B-type stars. Initiated in 2008 and completed in 2013, the project was supported by three Large Program allocations, as well as various programmes initiated by independent principal investigators, and archival resources. Ultimately, over 4800 circularly polarized spectra of 560 O and B stars were collected with the instruments ESPaDOnS (Echelle SpectroPolarimetric Device for the Observation of Stars) at the Canada-France-Hawaii Telescope, Narval at the Télescope Bernard Lyot and HARPSpol at the European Southern Observatory La Silla 3.6 m telescope, making MiMeS by far the largest systematic investigation of massive star magnetism ever undertaken. In this paper, the first in a series reporting the general results of the survey, we introduce the scientific motivation and goals, describe the sample of targets, review the instrumentation and observational techniques used, explain the exposure time calculation designed to provide sensitivity to surface dipole fields above approximately 100 G, discuss the polarimetric performance, stability and uncertainty of the instrumentation, and summarize the previous and forthcoming publications. [less ▲]Detailed reference viewed: 38 (9 ULiège) Detection of Solar-like Oscillations, Observational Constraints, and Stellar Models for þetas Cyg, the Brightest Star Observed By the Kepler MissionGuzik, J. A.; Houdek, G.; Chaplin, W. J. et alin Anuario de Psicologia Juridica (2016), 831Detailed reference viewed: 17 (0 ULiège) Kepler's first view of O-star variability: K2 data of five O stars in Campaign 0 as a proof of concept for O-star asteroseismologyBuysschaert, B.; Aerts, C.; Bloemen, S. et alin Monthly Notices of the Royal Astronomical Society (2015), 453We present high-precision photometric light curves of five O-type stars observed with the refurbished Kepler satellite during its Campaign 0. For one of the stars, we also assembled high-resolution ground ... [more ▼]We present high-precision photometric light curves of five O-type stars observed with the refurbished Kepler satellite during its Campaign 0. For one of the stars, we also assembled high-resolution ground-based spectroscopy with the HERMES spectrograph attached to the 1.2 m Mercator telescope. The stars EPIC 202060097 (O9.5V) and EPIC 202060098 (O7V) exhibit monoperiodic variability due to rotational modulation with an amplitude of 5.6 and 9.3 mmag and a rotation period of 2.63 and 5.03 d, respectively. EPIC 202060091 (O9V) and EPIC 202060093 (O9V:pe) reveal variability at low frequency but the cause is unclear. EPIC 202060092 (O9V:p) is discovered to be a spectroscopic binary with at least one multiperiodic β Cep-type pulsator whose detected mode frequencies occur in the range [0.11, 6.99] d[SUP]-1[/SUP] and have amplitudes between 0.8 and 2.0 mmag. Its pulsation spectrum is shown to be fully compatible with the ones predicted by core-hydrogen burning O-star models. Despite the short duration of some 33 d and the limited data quality with a precision near 100 μmag of these first K2 data, the diversity of possible causes for O-star variability already revealed from campaigns of similar duration by the MOST and CoRoT satellites is confirmed with Kepler. We provide an overview of O-star space photometry and give arguments why future K2 monitoring during Campaigns 11 and 13 at short cadence, accompanied by time-resolved high-precision high-resolution spectroscopy, opens up the possibility of in-depth O-star seismology. [less ▲]Detailed reference viewed: 36 (7 ULiège) KIC 4768731: a bright long-period roAp star in the Kepler fieldSmalley, B.; Niemczura, E.; Murphy, S. J. et alin Monthly Notices of the Royal Astronomical Society (2015), 452We report the identification of 61.45 d[SUP]-1[/SUP] (711.2 μHz) oscillations, with amplitudes of 62.6 μmag, in KIC 4768731 (HD 225914) using Kepler photometry. This relatively bright (V = 9.17 ... [more ▼]We report the identification of 61.45 d[SUP]-1[/SUP] (711.2 μHz) oscillations, with amplitudes of 62.6 μmag, in KIC 4768731 (HD 225914) using Kepler photometry. This relatively bright (V = 9.17) chemically peculiar star with spectral type A5 Vp SrCr(Eu) has previously been found to exhibit rotational modulation with a period of 5.21 d. Fourier analysis reveals a simple dipole pulsator with an amplitude that has remained stable over a 4-yr time span, but with a frequency that is variable. Analysis of high-resolution spectra yields stellar parameters of T[SUB]eff[/SUB] = 8100 ± 200 K, log g = 4.0 ± 0.2, [Fe/H] = +0.31 ± 0.24 and v sin i = 14.8 ± 1.6 km s[SUP]-1[/SUP]. Line profile variations caused by rotation are also evident. Lines of Sr, Cr, Eu, Mg and Si are strongest when the star is brightest, while Y and Ba vary in antiphase with the other elements. The abundances of rare earth elements are only modestly enhanced compared to other roAp stars of similar T[SUB]eff[/SUB] and log g. Radial velocities in the literature suggest a significant change over the past 30 yr, but the radial velocities presented here show no significant change over a period of 4 yr. [less ▲]Detailed reference viewed: 24 (0 ULiège) Magnetic fields in O-, B- and A-type stars on the main sequenceBriquet, Maryline in European Physical Journal Web of Conferences (2015, September 01)In this review, the latest observational results on magnetic fields in main-sequence stars with radiative envelopes are summarised together with the theoretical works aimed at explaining them.Detailed reference viewed: 38 (12 ULiège) Lamost Observations in the Kepler Field. I. Database of Low-resolution SpectraDe Cat, P.; Fu, J. N.; Ren, A. B. et alin Astrophysical Journal Supplement Series (2015), 220The nearly continuous light curves with micromagnitude precision provided by the space mission Kepler are revolutionizing our view of pulsating stars. They have revealed a vast sea of low-amplitude ... [more ▼]The nearly continuous light curves with micromagnitude precision provided by the space mission Kepler are revolutionizing our view of pulsating stars. They have revealed a vast sea of low-amplitude pulsation modes that were undetectable from Earth. The long time base of Kepler light curves allows for the accurate determination of the frequencies and amplitudes of pulsation modes needed for in-depth asteroseismic modeling. However, for an asteroseismic study to be successful, the first estimates of stellar parameters need to be known and they cannot be derived from the Kepler photometry itself. The Kepler Input Catalog provides values for the effective temperature, surface gravity, and metallicity, but not always with sufficient accuracy. Moreover, information on the chemical composition and rotation rate is lacking. We are collecting low-resolution spectra for objects in the Kepler field of view with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (lamost, Xinglong observatory, China). All of the requested fields have now been observed at least once. In this paper, we describe those observations and provide a useful database for the whole astronomical community. ) located at the Xinglong observatory, China. [less ▲]Detailed reference viewed: 25 (5 ULiège) Spectroscopic survey of Kepler stars. I. HERMES/Mercator observations of A- and F-type starsNiemczura, E.; Murphy, S. J.; Smalley, B. et alin Monthly Notices of the Royal Astronomical Society (2015), 450The Kepler space mission provided near-continuous and high-precision photometry of about 207,000 stars, which can be used for asteroseismology. However, for successful seismic modelling it is equally ... [more ▼]The Kepler space mission provided near-continuous and high-precision photometry of about 207,000 stars, which can be used for asteroseismology. However, for successful seismic modelling it is equally important to have accurate stellar physical parameters. Therefore, supplementary ground-based data are needed. We report the results of the analysis of high-resolution spectroscopic data of A- and F-type stars from the Kepler field, which were obtained with the HERMES spectrograph on the Mercator telescope. We determined spectral types, atmospheric parameters and chemical abundances for a sample of 117 stars. Hydrogen Balmer, Fe I, and Fe II lines were used to derive effective temperatures, surface gravities, and microturbulent velocities. We determined chemical abundances and projected rotational velocities using a spectrum synthesis technique. The atmospheric parameters obtained were compared with those from the Kepler Input Catalogue (KIC), confirming that the KIC effective temperatures are underestimated for A stars. Effective temperatures calculated by spectral energy distribution fitting are in good agreement with those determined from the spectral line analysis. The analysed sample comprises stars with approximately solar chemical abundances, as well as chemically peculiar stars of the Am, Ap, and Lambda Boo types. The distribution of the projected rotational velocity, Vsini, is typical for A and F stars and ranges from 8 to about 280 km/s, with a mean of 134 km/s. [less ▲]Detailed reference viewed: 29 (1 ULiège) New spectroscopic and polarimetric observations of the A0 supergiant HD 92207Hubrig, S.; Kholtygin, A. F.; Schöller, M. et alin Astronomische Nachrichten (2015), 336Our recent search for the presence of a magnetic field in the bright early A-type supergiant HD 92207 using FORS 2 in spectropolarimetric mode revealed the presence of a longitudinal magnetic field of the ... [more ▼]Our recent search for the presence of a magnetic field in the bright early A-type supergiant HD 92207 using FORS 2 in spectropolarimetric mode revealed the presence of a longitudinal magnetic field of the order of a few hundred Gauss. However, the definite confirmation of the magnetic nature of this object remained pending due to the detection of short-term spectral variability probably affecting the position of line profiles in left- and right-hand polarized spectra. We present new magnetic field measurements of HD 92207 obtained on three different epochs in 2013 and 2014 using FORS 2 in spectropolarimetric mode. A 3σ detection of the mean longitudinal magnetic field using the entire spectrum, _all=104±34 G, was achieved in observations obtained in 2014 January. At this epoch, the position of the spectral lines appeared stable. Our analysis of spectral line shapes recorded in opposite circularly polarized light, i.e. in light with opposite sense of rotation, reveals that line profiles in the light polarized in a certain direction appear slightly split. The mechanism causing such a behaviour in the circularly polarized light is currently unknown. Trying to settle the issue of short-term variability, we searched for changes in the spectral line profiles on a time scale of 8-10 min using HARPS polarimetric spectra and on a time scale of 3-4 min using time series obtained with the CORALIE spectrograph. No significant variability was detected on these time scales during the epochs studied. Based on observations collected with the CORALIE echelle spectrograph mounted on the 1.2-m Swiss telescope at La Silla Observatory, data obtained at the European Southern Observatory (ESO Prg. 092.D-0209(A), and data obtained from the ESO Science Archive Facility under request MSCHOELLER 102067). [less ▲]Detailed reference viewed: 37 (0 ULiège) B fields in OB stars (BOB): on the detection of weak magnetic fields in the two early B-type stars beta CMa and epsilon CMaFossati, L.; Castro, N.; Morel, Thierry et alin Astronomy and Astrophysics (2015), 574Within the context of the "B fields in OB stars (BOB)" collaboration, we used the HARPSpol spectropolarimeter to observe the early B-type stars beta CMa (HD44743; B1 II/III) and epsilon CMa (HD52089; B1.5 ... [more ▼]Within the context of the "B fields in OB stars (BOB)" collaboration, we used the HARPSpol spectropolarimeter to observe the early B-type stars beta CMa (HD44743; B1 II/III) and epsilon CMa (HD52089; B1.5 II). For both stars, we consistently detected the signature of a weak (<30 G in absolute value) longitudinal magnetic field. We determined the physical parameters of both stars and characterise their X-ray spectrum. For beta CMa, our mode identification analysis led to determining a rotation period of 13.6+/-1.2 days and of an inclination angle of the rotation axis of 57.6+/-1.7 degrees, with respect to the line of sight. On the basis of these measurements and assuming a dipolar field geometry, we derived a best fitting obliquity of ~22 degrees and a dipolar magnetic field strength (Bd) of ~100 G (60