367 citations · 8.3k across the 236 of their papers we have counts for
46 papers · 1 filter
Asteroseismology of chemically peculiar stars
O. Kochukhov
Pulsational variability is observed in several types of main sequence stars with anomalous chemical abundances. In this contribution I summarize the relationship between pulsations…
The MiMeS Project: Magnetism in Massive Stars
G. A. Wade, E. Alecian, D. A. Bohlender +11
The Magnetism in Massive Stars (MiMeS) Project is a consensus collaboration among the foremost international researchers of the physics of hot, massive stars, with the basic aim of…
The MiMeS Project: First Results
J. H. Grunhut, E. Alecian, D. A. Bohlender +11
Massive stars are those stars with initial masses above about 8 times that of the sun, eventually leading to catastrophic explosions in the form of supernovae. These represent the…
Discovery of very low amplitude 9-minute multiperiodic pulsations in the magnetic Ap star HD 75445
O. Kochukhov, S. Bagnulo, G. Lo Curto +1
We present our discovery of pulsational radial-velocity variations in the cool Ap star HD 75445, an object spectroscopically similar to the bright, rapidly-oscillating Ap (roAp) st…
New high resolution synthetic stellar libraries for the Gaia Mission
R. Sordo, A. Vallenari, J. C. Bouret +12
High resolution synthetic stellar libraries are of fundamental importance for the preparation of the Gaia Mission. We present new sets of spectral stellar libraries covering two sp…
MOST discovers a multimode delta Scuti star in a triple system: HD 61199
M. Hareter, O. Kochukhov, H. Lehmann +13
A field star, HD 61199 (V ~ 8), simultaneously observed with Procyon by the MOST (Microvariability & Oscillations of STars) satellite in continuous runs of 34, 17, and 34 days in 2…
Pulsation in the atmosphere of roAp stars
O. Kochukhov
High time resolution spectroscopy of roAp stars at large telescopes has led to a major breakthrough in our understanding of magnetoacoustic pulsations in these interesting objects.…
Magnetic fields and chemical peculiarities of the very young intermediate-mass binary system HD 72106
C. P. Folsom, G. A. Wade, O. Kochukhov +9
The recently discovered magnetic Herbig Ae and Be stars may provide qualitatively new information about the formation and evolution of magnetic Ap and Bp stars. We have performed a…
Pulsations in the atmosphere of the rapidly oscillating Ap star 10 Aquilae
M. Sachkov, O. Kochukhov, T. Ryabchikova +4
The rapidly oscillating Ap (roAp) star 10 Aql shows one of the lowest photometric pulsation amplitudes and is characterized by an unusual spectroscopic pulsational behavior compare…
Model atmospheres of magnetic chemically peculiar stars. A remarkable strong-field Bp SiCrFe star HD137509
Denis Shulyak, Oleg Kochukhov, Sergiy Khan
In the last few years we have developed stellar model atmospheres which included effects of anomalous abundances and strong magnetic field. The full treatment of anomalous Zeeman s…
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…
The Paschen-Back effect in the Li I 6708 A line and the presence of lithium in cool magnetic Ap stars
O. Kochukhov
A number of cool magnetic Ap stars show a prominent feature at lambda 6708 A. Its identification with Li I remains controversial due to a poor knowledge of the spectra of rare-eart…
Isotopic anomaly and stratification of Ca in magnetic Ap stars
T. Ryabchikova, O. Kochukhov, S. Bagnulo
We have carried out an accurate investigation of the Ca isotopic composition and stratification in the atmospheres of 23 magnetic chemically peculiar (Ap) stars of different temper…
The discovery of high-amplitude 10.9-minute oscillations in the cool magnetic Ap star HD 115226
O. Kochukhov, T. Ryabchikova, S. Bagnulo +1
We present the discovery of pulsational variations in the cool magnetic Ap star HD 115226 -- the first high-amplitude rapidly oscillating Ap star discovered with time-series spectr…
Magnetic Doppler Imaging of Active Stars
O. Kochukhov, N. Piskunov
We present a new implementation of the magnetic Doppler imaging technique, which aims at self-consistent temperature and magnetic mapping of the surface structures in cool active s…
Magnetic Doppler Imaging of Ap stars
J. Silvester, G. A. Wade, O. Kochukhov +2
Historically, the magnetic field geometries of the chemically peculiar Ap stars were modelled in the context of a simple dipole field. However, with the acquisition of increasingly…
Spectroscopic study of pulsations in the atmosphere of roAp star 10 Aql
M. Sachkov, O. Kochukhov, T. Ryabchikova +3
We present the analysis of spectroscopic time-series observations of the roAp star 10 Aql. Observations were carried out in July 2006 with the UVES and SARG spectrographs simultane…
Magnetic, Chemical and Rotational Properties of the Herbig Ae/Be Binary System HD 72106
C. P. Folsom, G. A. Wade, O. Kochukhov +5
Recently, strong, globally-ordered magnetic fields have been detected in some Herbig Ae and Be (HAeBe) stars, suggesting a possible evolutionary connection to main sequence magneti…
A search of very low amplitude magnetoacoustic pulsations with HARPS
O. Kochukhov, T. Ryabchikova, S. Bagnulo +1
We have obtained time-resolved spectroscopic observations for a sample of 10 cool Ap stars using the ultra-stable spectrograph HARPS at the ESO 3.6-m telescope. The aim of our stud…
Zeeman split lines in CP stars: a discovery of low-contrast fields in slow rotators?
O. Kochukhov
We show that high-resolution observations of resolved Zeeman split lines can be used to obtain new constraints on the stellar magnetic field geometry. In particular, the contrast o…
New generation model atmospheres for chemically peculiar stars
O. Kochukhov, D. Shulyak
The atmospheric structure of chemically peculiar stars deviates from that of normal stars with similar fundamental parameters due to unusual chemistry, abundance inhomogeneities an…
Magnetic fields, spots and weather in chemically peculiar stars
O. Kochukhov
New observational techniques and sophisticated modelling methods has led to dramatic breakthroughs in our understanding of the interplay between the surface magnetism, atomic diffu…
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…
Pulsation tomography of rapidly oscillating Ap stars. Resolving the third dimension in peculiar pulsating stellar atmospheres
T. Ryabchikova, M. Sachkov, O. Kochukhov +1
We present detailed analysis of the vertical pulsation mode cross-section in ten rapidly oscillating Ap (roAp) stars based on spectroscopic time-series observations. The aim of thi…