Search Publications
Empirical mass-loss rates and clumping properties of Galactic early-type O supergiants
Puls, J.; de Koter, A.; Sana, H. +7 more
Aims: We investigate the impact of optically thick clumping on spectroscopic stellar wind diagnostics in O supergiants and constrain wind parameters associated with porosity in velocity space. This is the first time the effects of optically thick clumping have been investigated for a sample of massive hot stars, using models which include a f…
Evidence for disequilibrium chemistry from vertical mixing in hot Jupiter atmospheres. A comprehensive survey of transiting close-in gas giant exoplanets with warm-Spitzer/IRAC
Deming, Drake; Burrows, Adam; Fortney, Jonathan J. +10 more
Aims: We present a large atmospheric study of 49 gas giant exoplanets using infrared transmission photometry with Spitzer/IRAC at 3.6 and 4.5 µm.
Methods: We uniformly analyze 70 photometric light curves of 33 transiting planets using our custom pipeline, which implements pixel level decorrelation. Augmenting our sample with 16 pre…
The Tarantula Massive Binary Monitoring. V. R 144: a wind-eclipsing binary with a total mass ≳140 M⊙
Howarth, I. D.; Crowther, P. A.; de Mink, S. E. +21 more
Context. The evolution of the most massive stars and their upper-mass limit remain insufficiently constrained. Very massive stars are characterized by powerful winds and spectroscopically appear as hydrogen-rich Wolf-Rayet (WR) stars on the main sequence. R 144 is the visually brightest WR star in the Large Magellanic Cloud. R 144 was reported to …
MPS-ATLAS: A fast all-in-one code for synthesising stellar spectra
Solanki, S. K.; Shapiro, A. I.; Tagirov, R. V. +6 more
Context. Stellar spectral synthesis is essential for various applications, ranging from determining stellar parameters to comprehensive stellar variability calculations. New observational resources as well as advanced stellar atmosphere modelling, taking three dimensional effects from radiative magnetohydrodynamics calculations into account, requi…
New mass-loss rates of B supergiants from global wind models
Krtička, J.; Kubát, J.; Krtičková, I.
Massive stars lose a significant fraction of mass during their evolution. However, the corresponding mass-loss rates are rather uncertain, especially for evolved stars. To improve this, we calculated global line-driven wind models for Galactic B supergiants. Our models predict radial wind structure and particularly the mass-loss rates and terminal…
Structure and dynamics of the inner nebula around the symbiotic stellar system R Aquarii
Alcolea, J.; Santander-García, M.; Bujarrabal, V. +5 more
Aims: We investigate the structure, dynamics, and chemistry of the molecule-rich nebula around the stellar symbiotic system R Aqr, which is significantly affected by the presence of a white dwarf (WD) companion. We study the effects of the strong dynamical interaction between the AGB wind and the WD and of photodissociation by the WD UV radia…
Broad-line region configuration of the supermassive binary black hole candidate PG1302-102 in the relativistic Doppler boosting scenario
Lu, Youjun; Ge, Junqiang; Ji, Xiang +2 more
PG1302-102 is thought to be a supermassive binary black hole (BBH) system according to the periodical variations of its optical and UV photometry, which may be interpreted as being due to the relativistic Doppler boosting of the emission mainly from the disk around the secondary black hole (BH) modulated by its orbital motion. In this paper, we in…
The first heavy-metal hot subdwarf composite binary SB 744
Bastian, A.; Németh, P.; Vos, J. +1 more
Aims: The long-period sdOB+G1V type spectroscopic binary SB 744 reveals strong lines of fluorine and lead in the optical spectrum of the sdOB star and subsolar metallicity in the G1V companion thanks to a radial velocity follow-up study. Using high-quality observations and Gaia astrometric data, we aim to measure the chemical composition and …
HD 144941: the most extreme helium-strong star
Fossati, L.; Przybilla, N.; Jeffery, C. S.
Since its discovery about 50 yr ago, HD 144941 has generally been classified as a peculiar member of the extreme helium (EHe) supergiant stars, a very rare class of low-mass hydrogen-deficient stars. We report the detection of a strong longitudinal magnetic field based on spectropolarimetry with FORS2 on the ESO VLT with surface-averaged longitudi…
Fundamental parameters of the Ap-stars GO And, 84 UMa, and κ Psc
Sitnova, T. M.; Romanovskaya, A. M.; Ryabchikova, T. A. +1 more
Aims: The aim of this work is to determine fundamental parameters of three Ap stars, GO And (HD 4778), κ Psc (HD 220825), and 84 UMa (HD 120198), using spectroscopic techniques. By analysing these stars, we complete the sample of Ap stars for which fundamental parameters have additionally been derived by means of interferometry. This enables …