Publications (34)
Ionization ratios and elemental abundances in the atmosphere of 68 Tauri
A. Aouina, R. Monier
We have derived the ionization ratios of twelve elements in the atmosphere of the star 68 Tauri (HD 27962) using an ATLAS9 model atmosphere with 72 layers computed for the effectiv…
HD 30963: a new HgMn star
R. Monier, M. Gebran, F. Royer
Using high dispersion high quality spectra of HD 30963 obtained with the echelle spectrograph SOPHIE at Observatoire de Haute Provence in November 2015, we show that this star, hit…
TESS Cycle 1 observations of roAp stars with 2-min cadence data
D. L. Holdsworth, M. S. Cunha, D. W. Kurtz +41
We present the results of a systematic search for new rapidly oscillating Ap (roAp) stars using the 2-min cadence data collected by the Transiting Exoplanet Survey Satellite (TESS)…
The nature of the late B-type stars HD 67044 and HD 42035
R. Monier, M. Gebran, F. Royer
While monitoring a sample of apparently slowly rotating superficially normal bright late B and early A stars in the northern hemisphere, we have discovered that HD 67044 and HD 420…
Chemical composition of A and F dwarfs members of the Hyades open cluster
M. Gebran, M. Vick, R. Monier +1
Abundances of 15 chemical elements have been derived for 28 F and 16 A stars members of the Hyades open cluster in order to set constraints on self-consistent evolutionary models i…
Line synthesis of several chemical elements from carbon to Bismuth in the spectrum of HD 72660
A. Lemonnier, R. Monier
The high resolution and high HARPS and STIS spectra of the A0Vm star HD72660 have been synthesised using model atmospheres and the line synthesis code Synspec49 in order to d…
Elemental abundances of HD 87240, member of the young open cluster NGC 3114
V. Wellenreiter, R. Monier, L. Fossati
We have determined the abundances of several chemical elements in the atmosphere of HD 87240, a member of the young open cluster NGC 3114. We have used the code ATLAS9 to compute a…
Microturbulence in A/F Am/Fm stars
M. Gebran, R. Monier, F. Royer +2
A programme to observe all A dwarfs in open clusters brighter than V=6.5 mag of various ages and in the field was initiated several years ago. In this work we present the current s…
Abundances determination of A, Am and F stars in the Pleiades and Coma Berenices clusters
M. Gebran, R. Monier, O. Richard
Abundances of 18 chemical elements have been derived for 27 A/Am and 16 F stars members of the Pleiades and Coma Berenices open clusters. We have specifically computed, with the Mo…
Chemical composition of A and F dwarfs members of the Pleiades open cluster
M. Gebran, R. Monier
Abundances of 18 chemical elements have been derived for 16 A (normal and chemically peculiar CP) and 5 F dwarfs members of the Pleiades open cluster in order to set constraints on…
Hyperfine Structure and Abundances of Heavy Elements in 68 Tauri (HD 27962)
S. Martinet, R. Monier
HD 27962, also known as 68 Tauri, is a Chemically Peculiar Am star member of the Hyades Open Cluster in the local arm of the Galaxy. We have modeled the high resolution SOPHIE (R=7…
The flat bottomed lines of Vega
R. Monier, M. Gebran, F. Royer +1
Using one high dispersion high quality spectrum of Vega (HR7001, A0V) obtained with the echelle spectrograph SOPHIE at Observatoire de Haute Provence, we have measured the centroid…
Discovery of new chemically peculiar late B-type stars: HD 67044
R. Monier, M. Gebran, F. Royer
HD 67044 currently assigned a B8 spectral type is one of the slowly rotating B stars situated in the northern hemisphere which we are currently observing. The selection criteria fo…
Atomic data needs for the modelling of stellar spectra
R. Monier
The current need for atomic data to model stellar spectra obtained in various wavelength ranges is described. The level of completeness and accuracy of these data is discussed.
Automated procedure to derive fundamental parameters of B and A stars: Application to the young cluster NGC 3293
E. Aydi, M. Gebran, R. Monier +3
This work describes a procedure to derive several fundamental parameters such as the effective temperature, surface gravity, equatorial rotational velocity and microturbulent veloc…
Elemental Abundance Analysis of the Early Type Members of the Open Cluster M6: Preliminary Results
T. Kilicoglu, R. Monier, L. Fossati
Differences in chemical composition among main sequence stars within a given cluster are probably due to differences in their masses and other effects such as radiative diffusion,…
A spectroscopic survey of the youngest field stars in the solar neighbourhood. I. The optically bright sample
P. Guillout, A. Klutsch, A. Frasca +8
We present the first results of a ground-based programme conducted on 1-4m class telescopes. Our sample consists of 1097 active and presumably young stars, all of them being optica…
Chemically Peculiar A/F Stars in Open Clusters of the Milky Way
M. Gebran, R. Monier
Abundance anomalies have been determined at the surface of many field and open cluster A and F dwarfs. These abundance anomalies are most likely caused by microscopic diffusion at…
A new method for the inversion of atmospheric parameters of A/Am stars
M. Gebran, W. Farah, F. Paletou +2
We present an automated procedure that derives simultaneously the effective temperature , the surface gravity logg, the metallicity [Fe/H], and the equatorial projected ro…
A search for magnetic Scuti stars in Kepler hybrid candidates
K. Thomson-Paressant, C. Neiner, P. Lampens +4
Numerous candidate hybrid stars of type Scuti - Doradus have been identified with the Kepler satellite. However, many of them lie outside the theoretically expected insta…
The chemical compositions of the 2 new HgMn stars HD 30085 and HD 30963. Comparison to Lupi A, Cap and HD 174567
R. Monier, E. Griffin, M. Gebran +3
We report on a detailed abundance study of the fairly bright slow rotators HD 30085 (A0 IV), HD 30963 (B9 III) and HD 174567 (A0 V), hitherto reported as normal stars and the sharp…
HR8844: A new hot Am star ?
R. Monier, M. Gebran, F. Royer
Using one archival high dispersion high quality spectrum of HR8844 (A0V) obtained with the echelle spectrograph SOPHIE at Observatoire de Haute Provence, we show that this star is…
Late stages of the evolution of A-type stars on the main sequence: comparison between observed chemical abundances and diffusion models for 8 Am stars of the Praesepe cluster
L. Fossati, S. Bagnulo, R. Monier +5
Aims. We aim to provide observational constraints on diffusion models that predict peculiar chemical abundances in the atmospheres of Am stars. We also intend to check if chemical…
Four new HgMn stars: HD 18104, HD 30085, HD 32867, HD 53588
R. Monier, M. Gebran, F. Royer
We have detected four new HgMn stars, while monitoring a sample of apparently slowly rotating superficially normal bright late B and early A stars in the northern hemisphere. Impor…
Elemental Abundance Analysis of Single and Binary Late-B Stars Using Sub-meter Class Telescopes: HR 342, HR 769, HR 1284, and HR 8705
T. KılıçoÄlu, R. Monier
We test the capabilities of 0.4 m telescopes equipped with an échelle spectrograph to derive fundamental parameters and elemental abundances of four late-B type stars: HR 342, HR…
Line identifications in the spectrum of Lupi A
R. Monier, T. KılıçoÄlu
We present new abundance determinations for the sharp-lined HgMn star Ï Lupi A from archival FEROS spectra. Selected unblended lines with accurate atomic data have been synthesize…
HR 8844: a new transition object between the Am stars and the HgMn stars ?
R. Monier, M. Gebran, F. Royer +2
While monitoring a sample of apparently slowly rotating superficially normal early A stars, we have discovered that HR 8844 (A0 V), is actually a new Chemically Peculiar star. We h…
Normal A0--A1 stars with low rotational velocities. I. Abundance determination and classification
F. Royer, M. Gebran, R. Monier +6
Context. The study of rotational velocity distributions for normal stars requires an accurate spectral characterization of the objects in order to avoid polluting the results with…
The effect of rotation on the abundances of the chemical elements of the A-type stars in the Praesepe cluster
L. Fossati, S. Bagnulo, J. Landstreet +5
We study how chemical abundances of late B-, A- and early F-type stars evolve with time, and we search for correlations between the abundance of chemical elements and other stellar…
HR 62: A New Evolved Chemically Peculiar Late-B Star?
T. KılıçoÄlu, R. Monier
The spectrum of the evolved B8 III giant HR 62 exhibits weak He-lines and strong Mn and P lines. HR 62 therefore resembles both a HgMn star (CP3) and a He-weak PGa star (CP4). This…
HR 7098: A new cool HgMn star?
R. Monier, M. Gebran, F. Royer +1
Using one archival high dispersion high quality spectrum of HR 7098 (A0V) obtained with the échelle spectrograph SOPHIE at Observatoire de Haute Provence, we show that this star i…
The peculiar abundance pattern of the new Hg-Mn star HD 30085
R. Monier, M. Gebran, F. Royer +1
Using high-dispersion, high-quality spectra of HD 30085 obtained with the echelle spectrograph SOPHIE at Observatoire de Haute Provence, we show that this star contains strong line…
GYES, a multifibre spectrograph for the CFHT
P. Bonifacio, S. Mignot, J. -L. Dournaux +38
We have chosen the name of GYES, one of the mythological giants with one hundred arms, offspring of Gaia and Uranus, for our instrument study of a multifibre spectrograph for the p…
Chemical composition of A and F dwarf members of the Coma Berenices open cluster
M. Gebran, R. Monier, O. Richard
Abundances of 18 chemical elements have been derived for 11 A (normal and Am) and 11 F dwarfs members of the Coma Berenices open cluster in order to set constraints on evolutionary…