Search Publications
Identifying quiescent compact objects in massive Galactic single-lined spectroscopic binaries
Shenar, T.; Sana, H.; Hawcroft, C. +13 more
Context. The quest to detect dormant stellar-mass black holes (BHs) in massive binaries (i.e. OB+BH systems) is challenging; only a few candidates have been claimed to date, all of which must still be confirmed.
Aims: To search for these rare objects, we study 32 Galactic O-type stars that were reported as single-lined spectroscopic binaries …
CRIRES high-resolution near-infrared spectroscopy of diffuse interstellar band profiles. Detection of 12 new DIBs in the YJ band and the introduction of a combined ISM sight line and stellar analysis approach
Butler, K.; Weßmayer, D.; Przybilla, N. +7 more
Aims: A high spectral resolution investigation of diffuse interstellar bands (DIBs) in the near-infrared (YJ band) is conducted to test new methods, to confirm and improve existing parameters, and to search for new DIBs.
Methods: The CRyogenic high-resolution InfraRed Echelle Spectrograph (CRIRES) on the European Southern Observatory's V…
Quantitative spectroscopy of B-type supergiants
Butler, K.; Weßmayer, D.; Przybilla, N.
Context. B-type supergiants are versatile tools to address a number of highly-relevant astrophysical topics, ranging from stellar atmospheres over stellar and galactic evolution to the characterisation of interstellar sightlines and to the cosmic distance scale.
Aims: A hybrid non-local thermodynamic equilibrium (LTE) approach, involving line…
Apsidal motion in massive eccentric binaries in NGC 6231. The case of HD 152219
Farnir, M.; Dupret, M. -A.; Rauw, G. +2 more
Context. The measurement of the apsidal motion in close eccentric massive binary systems provides essential information to probe the internal structure of the stars that compose the system.
Aims: Following the determination of the fundamental stellar and binary parameters, we make use of the tidally induced apsidal motion to infer constraints…
Non-local thermodynamic equilibrium spectral analysis of five hot, hydrogen-deficient pre-white dwarfs
Raddi, Roberto; Munari, Ulisse; Werner, Klaus +3 more
Hot, compact, hydrogen-deficient pre-white dwarfs (pre-WDs) with effective temperatures of Teff > 70 000 K and a surface gravity of 5.0 < logg < 7.0 are rather rare objects despite recent and ongoing surveys. It is believed that they are the outcome of either single star evolution (late helium-shell flash or late helium-core fl…
Towards a consistent model of the hot quadruple system HD 93206 = QZ Carinæ. I. Observations and their initial analyses
Wolf, M.; Chini, R.; Harmanec, P. +18 more
The hot nine-component system HD 93206, which contains a gravitationally bounded eclipsing Ac1+Ac2 binary (P = 5.9987 d) and a spectroscopic Aa1+Aa2 (P = 20.734 d) binary can provide important insights into the origin and evolution of massive stars. Using archival and new spectra, and a rich collection of ground-based and space photometric observa…
Cyclic changes in the interacting binary RX Cassiopeiae
Jurkovic, M. I.; Mennickent, R. E.; Djurašević, G. +6 more
We analyzed 109 years of published photometry and times of minima of the eclipsing interacting binary RX Cas. The inclusion of 171 previously unnoticed minima confirms the tendency of an increase in the orbital period at a rate of 1.84 s per cycle. We also find evidence of variations in the length of the previously reported long photometric cycle …
Revisiting the high-mass transfer close binary star system AU Monocerotis
Shore, Steven N.; Armeni, Antonio
Context. AU Monocerotis is an eclipsing, double-lined spectroscopic binary with a period of 11 days that is in a state of extreme mass transfer, consisting of a main sequence B-type embedded in a thick accretion disk fed by a Roche lobe overflowing evolved G-type companion. It is also one of the double periodic variable Algol-type binaries.
A…