Search Publications
The Wolf-Rayet binaries of the nitrogen sequence in the Large Magellanic Cloud. Spectroscopy, orbital analysis, formation, and evolution
Hamann, W. -R.; Oskinova, L. M.; Sander, A. A. C. +11 more
Context. Massive Wolf-Rayet (WR) stars dominate the radiative and mechanical energy budget of galaxies and probe a critical phase in the evolution of massive stars prior to core collapse. It is not known whether core He-burning WR stars (classical WR; cWR) form predominantly through wind stripping (w-WR) or binary stripping (b-WR). Whereas spectro…
A UV and optical study of 18 old novae with Gaia DR2 distances: mass accretion rates, physical parameters, and MMRD
Selvelli, Pierluigi; Gilmozzi, Roberto
We combine the results of our earlier study of the UV characteristics of 18 classical novae (CNe) with data from the literature and with the recent precise distance determinations from the Gaia satellite to investigate the statistical properties of old novae. All final parameters for the sample include a detailed treatment of the errors and their …
Hot UV-bright stars of galactic globular clusters
Lanz, T.; Miller Bertolami, M. M.; Landsman, W. B. +1 more
Context. We have performed a census of the UV-bright population in 78 globular clusters using wide-field UV telescopes. This population includes a variety of phases of post-horizontal branch (HB) evolution, including hot post-asymptotic giant branch (AGB) stars, and post-early AGB stars. There are indications that old stellar systems like globular…
Heavy metals in intermediate He-rich hot subdwarfs: the chemical composition of HZ 44 and HD 127493
Heber, U.; Latour, M.; Dorsch, M.
Context. Hot subluminous stars can be spectroscopically classified as subdwarf B (sdB) and O (sdO) stars. While the latter are predominantly hydrogen deficient, the former are mostly helium deficient. The atmospheres of most sdOs are almost devoid of hydrogen, whereas a small group of hot subdwarf stars of mixed H/He composition exists, showing ex…
Consistent dust and gas models for protoplanetary disks. IV. A panchromatic view of protoplanetary disks
Waters, L. B. F. M.; Pinte, C.; Ménard, F. +17 more
Context. Consistent modeling of protoplanetary disks requires the simultaneous solution of both continuum and line radiative transfer, heating and cooling balance between dust and gas and, of course, chemistry. Such models depend on panchromatic observations that can provide a complete description of the physical and chemical properties and energy…
Probing the weak wind phenomenon in Galactic O-type giants
Bouret, J. -C.; Pereira, C. B.; Marcolino, W. L. F. +1 more
Aims: Analyses of Galactic late O dwarfs (O8-O9.5V stars) raised the "weak wind problem": spectroscopic mass-loss rates (Ṁ) are up to two orders of magnitude lower than the theoretical values. We investigated the stellar and wind properties of Galactic late O giants (O8-O9.5III stars). These stars have luminosities log (L⋆ / L…
HST/STIS analysis of the first main sequence pulsar CU Virginis
Pigulski, A.; Trigilio, C.; Leto, P. +9 more
Context. CU Vir has been the first main sequence star that showed regular radio pulses that persist for decades, resembling the radio lighthouse of pulsars and interpreted as auroral radio emission similar to that found in planets. The star belongs to a rare group of magnetic chemically peculiar stars with variable rotational period.
Aims: We…
LMC S154: the first Magellanic symbiotic recurrent nova
Gromadzki, Mariusz; Miszalski, Brent; Iłkiewicz, Krystian +3 more
Classical nova outburst has been suggested for a number of extragalactic symbiotic stars, but in none of the systems has it been proven. In this work we study the nature of one of these systems, LMC S154. We gathered archival photometric observations in order to determine the timescales and nature of variability in this system. Additionally we car…
Heavy metal enrichment in the intermediate He-sdOB pulsator Feige 46
Heber, U.; Latour, M.; Dorsch, M.
The intermediate He-enriched hot subdwarf star Feige 46 was recently reported as the second member of the V366 Aqr (or He-sdOBV) pulsating class. Feige 46 is very similar to the prototype of the class, LS IV - 14°116, not only in terms of pulsational properties, but also in terms of atmospheric parameters and kinematic properties. LS IV - 14°116 i…
HD 96446: a long-period binary with a strongly magnetic He-rich primary with β Cephei pulsations
Järvinen, S.; González, J. F.; Butler, K. +14 more
Aims: HD 96446 is a magnetic B2p He-strong star that has been reported to be a β Cep pulsator. We present a detailed spectroscopic analysis of this object based on an intensive observational data set obtained in a multisite campaign with the spectrographs CORALIE, FEROS, and HARPS (La Silla); UVES (Paranal); HERCULES (Mt. John Observatory); a…