Publications (25)
The hematite (alpha-Fe_2 O_3) (0001) surface: evidence for domains of distinct chemistry
X. -G. Wang, W. Weiss, Sh. K. Shaikhutdinov +5
Using spin-density functional theory we investigated various possible structures of the hematite (0001) surface. Depending on the ambient oxygen partial pressure, two geometries ar…
Evolving pulsation of the slowly rotating magnetic Cep star CMa
G. A. Wade, A. Pigulski, S. Begy +11
Recent BRITE-Constellation space photometry of the slowly rotating, magnetic Cep pulsator CMa permits a new analysis of its pulsation properties. Analysis of the two-co…
Probing populations of red giants in the galactic disk with CoRoT
A. Miglio, J. Montalban, F. Baudin +6
The detection with CoRoT of solar-like oscillations in nearly 800 red giants in the first 150-days long observational run paves the way for detailed studies of populations of galac…
Solar-like oscillations in red giants in the CoRoT exo-field
S. Hekker, C. Barban, T. Kallinger +4
Asteroseismic observations from space can provide us with long time series of uninterrupted high quality data for many stars at the same time. The CoRoT satellite (Convection Rotat…
Looking for a connection between the Am phenomenon and hybrid delta Sct - gamma Dor pulsation: a determination of the fundamental parameters and abundances of HD 114839 and BD +18 4914
M. Hareter, L. Fossati, W. Weiss +4
Delta Sct - gamma Dor hybrids pulsate simultaneously in p- and g-modes, which carry information on the structure of the envelope as well as to the core. Hence they are key objects…
Discovery of new roAp pulsators in the UVES survey of cool magnetic Ap stars
O. Kochukhov, D. Alentiev, T. Ryabchikova +4
We have carried out a survey of short-period pulsations among a sample of carefully chosen cool Ap stars using time-resolved observations with the UVES spectrometer at the ESO 8-m…
Surface structure of the CoRoT CP2 target star HD 50773
T. Lüftinger, H. -E. Fröhlich, W. Weiss +15
We compare surface maps of the chemically peculiar star HD 50773 produced with a Bayesian technique and based on high quality CoRoT photometry with those derived from rotation phas…
Gamma Dor and Gamma Dor - Delta Sct Hybrid Stars In The CoRoT LRa01
M. Hareter, P. Reegen, A. Miglio +7
A systematic search for gamma Dor and gamma Dor - delta Scuti hybrid pulsators was conducted on the CoRoT LRa01 Exo-archive yielding a total of 418 gamma Dor and 274 hybrid candida…
First HARPSpol discoveries of magnetic fields in massive stars
E. Alecian, O. Kochukhov, C. Neiner +14
In the framework of the Magnetism in Massive Stars (MiMeS) project, a HARPSpol Large Program at the 3.6m-ESO telescope has recently started to collect high-resolution spectropolari…
Abundance analysis of seven delta Scuti Stars
L. Fossati, K. Kolenberg, P. Reegen +1
The current knowledge of the abundance pattern in delta Scuti stars is based on the analysis of just a few field stars. We aim to determine the general chemical properties of the a…
Ultrafast light-induced Coherent Optical and Acoustic Phonons in few Quintuple Layers of Topological Insulators Bi2Te3
W. Weiss, K. Balin, R. Rapacz +4
Ultrafast lattice dynamics of few quintuple layers of topological insulator (TI) BiTe is studied with time-resolved optical pump-probe spectroscopy. Both optical and acoust…
Lupi: measuring the heartbeat of a doubly-magnetic massive binary with BRITE-Constellation
H. Pablo, M. Shultz, J. Fuller +15
Lupi A is a binary system consisting of two main sequence early B-type stars Aa and Ab in a short period, moderately eccentric orbit. The close binary pair is the onl…
Explaining the Praesepe blue straggler HD 73666
L. Fossati, S. Mochnacki, J. Landstreet +1
The blue straggler phenomenon is not yet well explained by current theory; however, evolutionary models of star clusters call for a good knowledge of it. Here we try to understand…
Science with a small two-band UV-photometry mission II: Observations of stars and stellar systems
J. KrtiÄka, J. BenáÄek, J. Budaj +32
We outline the impact of a small two-band UV-photometry satellite mission on the field of stellar physics, magnetospheres of stars, binaries, stellar clusters, interstellar matter,…
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…
GAUDI: a preparatory archive for the COROT mission
E. Solano, C. Catala, R. Garrido +34
The GAUDI database (Ground-based Asteroseismology Uniform Database Interface, http://sdc.laeff.esa.es/gaudi/) is a preparatory archive for the COROT (COnvection, ROtation and plane…
Discovery of the longest-period rapidly oscillating Ap star HD177765
D. Alentiev, O. Kochukhov, T. Ryabchikova +3
We present the discovery of a long-period, rapidly oscillating Ap star, HD177765. Using high-resolution time-series observations obtained with UVES at the ESO VLT telescope, we fou…
The Most Massive Heartbeat: An In-depth Analysis of ι Orionis
Herbert Pablo, N. D. Richardson, J. Fuller +17
ι Ori is a well studied massive binary consisting of an O9 III + B1 III/IV star. Due to its high eccentricity (e = 0.764) and short orbital period (P orb = 29.13376 d), it has bee…
Multi-element Doppler imaging of the CP2 star HD 3980
N. Nesvacil, T. Lüftinger, D. Shulyak +8
In atmospheres of magnetic main-sequence stars, the diffusion of chemical elements leads to a number of observed anomalies, such as abundance spots across the stellar surface. The…
Exoplanet Characterization and the Search for Life
J. Kasting, W. Traub, A. Roberge +119
Over 300 extrasolar planets (exoplanets) have been detected orbiting nearby stars. We now hope to conduct a census of all planets around nearby stars and to characterize their atmo…
Red-giant seismic properties analyzed with CoRoT
B. Mosser, K. Belkacem, M. J. Goupil +10
The CoRoT 5-month long observation runs give us the opportunity to analyze a large variety of red-giant stars and to derive fundamental stellar parameters from their asteroseismic…
Abundance analysis of the Gamma Doradus - Delta Scuti hybrid metallic line (Am) star HD 8801
R. Neuteufel, W. Weiss, G. Handler
Low frequency oscillation, typical for Gamma Doradus g-mode type stellar core sensitive pulsation, as well as higher frequency Delta Scuti type pulsation typical for p-modes, sensi…
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…
BRITE photometry of the massive post-RLOF system HD149404
G. Rauw, A. Pigulski, Y. Nazé +12
HD149404 is an evolved non-eclipsing O-star binary that has previously undergone a Roche lobe overflow interaction. Understanding some key properties of the system requires a deter…
CoRoT's view of newly discovered B-star pulsators: results for 358 candidate B pulsators from the initial run's exoplanet field data
P. Degroote, C. Aerts, M. Ollivier +18
We search for new variable B-type pulsators in the CoRoT data assembled primarily for planet detection, as part of CoRoT's Additional Programme. We aim to explore the properties of…