Search Publications
An asteroseismic study of the O9V star HD 46202 from CoRoT space-based photometry
Auvergne, M.; Baudin, F.; Michel, E. +13 more
The O9V star HD 46202, which is a member of the young open cluster NGC 2244, was observed by the CoRoT satellite in October/November 2008 during a short run of 34 days. From the very high-precision light curve, we clearly detect β Cep-like pulsation frequencies with amplitudes of ~0.1 mmag and below. A comparison with stellar models was performed …
Constraining the structure of the planet-forming region in the disk of the Herbig Be star HD 100546
Pinte, C.; Ménard, F.; Weigelt, G. +8 more
Context. Studying the physical conditions in circumstellar disks is a crucial step toward understanding planet formation and disk evolution. Of particular interest is the case of HD 100546, a Herbig Be star that presents a gap within the first 13 AU of its protoplanetary disk, a gap that may originate in the dynamical interactions of a forming pla…
Abundances in planetary nebulae: NGC 1535, NGC 6629, He2-108, and Tc1
Pottasch, S. R.; Bernard-Salas, J.; Surendiranath, R.
Context. Models have been made of stars of a given mass that produce planetary nebulae that usually begin on the AGB (although they may begin earlier) and run to the white dwarf stage. While these models cover the so-called dredge-up phases when nuclear reactions occur and the newly formed products are brought to the surface, it is important to co…
The fundamental parameters of the roAp star γ Equulei
Chesneau, O.; Goldfinger, P. J.; Sturmann, J. +18 more
Context. A precise comparison of the predicted and observed locations of stars in the H-R diagram is needed when testing stellar interior theoretical models. For doing this, one must rely on accurate, observed stellar fundamental parameters (mass, radius, luminosity, and abundances).
Aims: We determine the angular diameter of the rapidly osci…
The two components of the evolved massive binary LZ Cephei. Testing the effects of binarity on stellar evolution
Bouret, J. -C.; Martins, F.; Donati, J. -F. +2 more
Aims: We present an in-depth study of the two components of the binary system LZ Cep to constrain the effects of binarity on the evolution of massive stars.
Methods: We analyzed a set of high-resolution, high signal-to-noise ratio optical spectra obtained over the orbital period of the system to perform a spectroscopic disentangling and …
Photometric observations of asteroid 4 Vesta by the OSIRIS cameras onboard the Rosetta spacecraft
Sierks, H.; Mottola, S.; Barucci, M. A. +2 more
Aims: We report on new observations of asteroid 4 Vesta obtained on 1 May 2010 with the optical system OSIRIS onboard the ESA Rosetta mission. One lightcurve was taken at a phase angle (52°) larger than achievable from ground-based observations together with a spectrophotometric sequence covering the 260 to 990 nm wavelength range.
Metho…
A comprehensive approach to analyzing the XMM-Newton data of Seyfert 1 galaxies
Santos-Lleó, M.; Krongold, Y.; Rodríguez-Pascual, P. +3 more
Aims: We seek a comprehensive analysis of all the information provided by the XMM-Newton satellite of the four Seyfert 1 galaxies ESO 359-G19, HE 1143-1810, CTS A08.12, and Mrk 110, including the UV range, to characterize the different components that are emitting and absorbing radiation in the vicinity of the active nucleus.
Methods: Th…
An intrinsic source of reddening in the cataclysmic variable SS Cygni
Gaudenzi, S.; Giovannelli, F.; Lombardi, R. +2 more
By using the INES archive of the IUE satellite, we analyzed the spectra of SS Cygni in quiescence in order to determine the value of the reddening of the binary system. The reddening of the system is reported in the literature with values that vary significantly from one another. The results demonstrate that the reddening is comprised by two compo…
XMM-Newton observations of the X-ray soft polar QS Telescopii
Burwitz, V.; Dreizler, S.; Walter, F. M. +4 more
Context. On the basis of XMM-Newton observations, we investigate the energy balance of selected magnetic cataclysmic variables, which have shown an extreme soft-to-hard X-ray flux ratio in the ROSAT All-Sky Survey.
Aims: We intend to establish the X-ray properties of the system components, their flux contributions, and the accretion geometry …