Search Publications
Hertzsprung gap stars in nearby galaxies and the quest for luminous red nova progenitors
Blagorodnova, Nadejda; van Roestel, Jan; Vreeswijk, Paul M. +5 more
Context. After the main sequence phase, stars more massive than 2.5 M⊙ rapidly evolve through the Hertzsprung gap as yellow giants and yellow supergiants (YSGs) before settling into the red giant branch. Identifying Hertzsprung gap stars in nearby galaxies is crucial for pinpointing progenitors of luminous red novae (LRNe) – astrophysic…
A Maia-type candidate was misclassified: V424 Cep is an eclipsing β Cep-type pulsator in a triple system
Schmutz, W.; Koenigsberger, G.; Richer, M. G. +2 more
Context. V424 Cephei is an eclipsing binary system that has been classified as a Maia variable candidate. These objects are pulsators that apparently lie outside the theoretical instability strips. Aims. We determine the properties of V424 Cep and identify the nature of the pulsating variable. Methods. We analyzed photometric data obtained over th…
Cooling rate and turbulence in the intracluster medium of the cool-core cluster Abell 2667
Rodighiero, G.; Gastaldello, F.; Tozzi, P. +8 more
Context. We present a detailed analysis of the thermal X-ray emission from the intracluster medium in the cool-core galaxy cluster Abell 2667 at z = 0.23. Aims. Our main goal is to detect low-temperature (< 2 keV) X-ray emitting gas associated with a potential cooling flow connecting the hot intracluster medium reservoir to the cold gas phase r…
First unambiguous detection of ammonia in the atmosphere of a planetary mass companion with JWST/MIRI coronagraphs
Henning, Thomas; Güdel, Manuel; Boccaletti, Anthony +28 more
Context. The newly accessible mid-infrared (MIR) window offered by the James Webb Space Telescope (JWST) for exoplanet imaging is expected to provide valuable information to characterize their atmospheres. In particular, coronagraphs on board the JWST Mid-InfraRed instrument (MIRI) are capable of imaging the coldest directly imaged giant planets a…
Disentangling the stellar atmosphere and the focused wind in different accretion states of Cygnus X-1
Russell, D. M.; Svoboda, J.; Skarka, M. +8 more
Context. In high-mass X-ray binaries (HMXBs), the compact object accretes the strong stellar wind of an O-B supergiant companion star. X-ray flux variations alter the stellar wind's ionization state and optical line profiles, which are important in the determination of the orbital parameters of the system. Aims. We analyzed the state-dependent var…
Signatures of simulated spiral arms on radial actions
Recio-Blanco, A.; McMillan, P. J.; Palicio, P. A. +7 more
Context. Spiral arms play a key role in the evolution of disc galaxies, defining their morphology, star formation, chemistry, and dynamics. Among their various implications, it has been observed in the Milky Way disc that the distribution of Gaia Data Release 3 (DR3) radial actions exhibits structures that might be related to the spiral arms. Aims…
JOYS: The [D/H] abundance derived from protostellar outflows across the Galactic disk measured with JWST
Henning, T.; Güdel, M.; Ray, T. P. +11 more
Context. The total deuterium abundance [D/H] in the universe is set by just two processes: the creation of deuterium in Big Bang nucleosynthesis at an abundance of [D/H] = 2.58 ± 0.13 × 10‑5, and its destruction within stellar interiors (astration). Measurements of variations in the total [D/H] abundance can thus potentially provide a p…
Spatial distribution and clustering properties of the young stellar populations in the Carina Nebula complex and Car OB1
Preibisch, T.; Göppl, C.
Aims. We use Gaia DR3 astrometry and photometry to analyze the spatial distribution of the young stellar populations and stellar clusters and to search for new OB star candidates in the Carina Nebula complex and the full extent (∼5°, corresponding to ∼200 pc) of the Car OB1 association. Methods. We first performed a new census of high-mass stars i…
Exploring coronal abundances of M dwarfs at moderate activity levels
Wood, B. E.; Alvarado-Gómez, J. D.; Poppenhäger, K. +1 more
Context. Main sequence stars of spectral types F, G, and K with low to moderate activity levels exhibit a recognizable pattern known as the first ionization potential effect (FIP effect), where elements with lower first ionization potentials are more abundant in the stellar corona than in the photosphere. In contrast, high activity main sequence s…
Statistical investigation of solar flares showing quasi-periodicity based on STIX quick-look light curves
Mrozek, T.; Szaforz, Ż.; Tomczak, M.
Context. The emission of radiation associated with the release of energy in solar flares is often modulated according to a quasi-oscillatory pattern. This behavior is known as quasi-periodic pulsation (QPP). In this work, the STIX instrument on board Solar Orbiter was used to study solar flares that show quasi-periodic variations in X-ray emission…