Search Publications
KMHK 1762: Another star cluster in the Large Magellanic Cloud age gap
Cignoni, M.; Tosi, M.; Ripepi, V. +11 more
Context. The star cluster (SC) age distribution of the Large Magellanic Cloud (LMC) exhibits a gap from ∼4 to 10 Gyr ago, with an almost total absence of SCs. Within this age gap, only two confirmed SCs have been identified hitherto. Nonetheless, the star field counterpart does not show the same characteristics, making the LMC a peculiar galaxy wh…
Orbital and atmospheric parameters of two wide O-type subdwarf binaries: BD−11o162 and Feige 80
Németh, Péter; Tkachenko, Andrew; van Winckel, Hans +4 more
Context. There are 23 long-period binary systems discovered to date that contain a B-type hot subdwarf whose orbital parameters have been fully solved. They evolve into O-type subdwarfs (sdO) once the helium burning transitions from the core to the He shell. Their study will help constraint parameters on the formation and evolution of these binari…
An intermediate polar candidate toward the Galactic plane
Campana, S.; Haberl, F.; Ponti, G. +5 more
Context. For the past decade, it has been suggested that intermediate polars (IPs), a subclass of magnetic cataclysmic variables (CVs), are one of the main contributors to the hard diffuse X-ray emission from the Galactic center (GC) and Galactic ridge.
Aims: In our ongoing XMM-Newton survey of the central region of the Galactic disk (20° ×2°…
Analytic modeling of recurrent Forbush decreases caused by corotating interaction regions
Vršnak, B.; Dumbović, M.; Heber, B. +1 more
Context. On scales of days, the galactic cosmic ray (GCR) flux is affected by coronal mass ejections and corotating interaction regions (CIRs), causing so-called Forbush decreases and recurrent Forbush decreases (RFDs), respectively.
Aims: We explain the properties and behavior of RFDs recorded at about 1 au that are caused by CIRs generated …
Spectroscopic observation of a transition region network jet
Peter, H.; Chitta, L. P.; Gorman, J.
Aims: Ubiquitous transition region (TR) network jets are considered to be substantial sources of mass and energy to the corona and solar wind. We conduct a case study of a network jet to better understand the nature of mass flows along its length and the energetics involved in its launch.
Methods: We present an observation of a jet with …
HD 60431, the CP2 star with the shortest rotational period. Physical parameters and period analysis
Paunzen, E.; Bernhard, K.; Hümmerich, S. +5 more
Context. CP2 stars show periodic photometric, spectroscopic, and magnetic variations with the rotational period. They are generally slow rotators, with rotational periods exceeding half a day, except for the late B-type star HD 60431, which has an unusually short rotational period of 0.4755 days. As slow rotation is deemed a necessary criterion fo…
The X-ray Emission of γ Cassiopeiae During the 2020-2021 Disc Eruption
Motch, C.; Smith, M. A.; Nazé, Y. +3 more
Context. γ Cas is known for its unusually hard and intense X-ray emission. This emission could trace accretion by a compact companion, wind interaction with a hot sub-dwarf companion, or magnetic interaction between the star and its Be decretion disc.
Aims: These various scenarios should lead to diverse dependences of the hard X-ray emission …
The first study of four doubly eclipsing systems
Zasche, P.; Henzl, Z.; Kára, J.
We present the discovery and the very first analysis of four stellar systems showing two periods of eclipses, that are the objects classified as doubly eclipsing systems. Some of them were proved to orbit each other thanks to their eclipse-timing-variations (ETVs) of both pairs, hence they really constitute rare quadruples with two eclipsing pairs…
Surface brightness-colour relations of dwarf stars from detached eclipsing binaries. I. Calibrating sample
Kervella, P.; Maxted, P. F. L.; Southworth, J. +19 more
Aims: Surface brightness - colour relations (SBCRs) are very useful tools for predicting the angular diameters of stars. They offer the possibility to calculate very precise spectrophotometric distances by the eclipsing binary method or the Baade-Wesselink method. Double-lined Detached Eclipsing Binary stars (SB2 DEBs) with precisely known tr…
Gaia-TESS synergy: improving the identification of transit candidates
Latham, David W.; Collins, Karen A.; Mazeh, Tsevi +5 more
Context. The TESS team periodically issues a new list of transiting exoplanet candidates based on the analysis of the accumulating light curves obtained by the satellite. The list includes the estimated epochs, periods, and durations of the potential transits. As the point spread function (PSF) of TESS is relatively wide, follow-up photometric obs…