Search Publications
Revisiting symbiotic binaries with interferometry: I. The PIONIER archival collection
Boffin, Henri M. J.; Merc, Jaroslav
Symbiotic stars serve as exceptional laboratories for investigating mass transfer processes in binary systems. However, the dominant mechanism of mass transfer from the red giant donor to the compact accretor – typically a white dwarf or, in rare cases, a neutron star – remains unclear. It is uncertain whether it is driven primarily by the stellar…
Testing the mass-radius relation of white dwarfs in common proper-motion pairs: I. Hydrogen-dominated atmospheres
Rebassa-Mansergas, Alberto; Raddi, Roberto; Camisassa, Maria E. +6 more
Context. White dwarf masses are among the most important properties used to constrain their past and future evolution. Direct estimates of white dwarf masses are crucial for assessing the validity of theoretical evolutionary models and methods of analysis. Aims. The main goal of this work was to measure the masses and radii of white dwarfs that be…
Using the STIX background detector as a proxy for GOES
Volpara, Anna; Krucker, Säm; Dickson, Ewan C. M. +4 more
Context. The Spectrometer/Telescope for Imaging X-Rays (STIX) on board Solar Orbiter was designed to observe solar flares in the X-ray range of 4‑150 keV, providing spectral, temporal, and spatial information. Besides 30 imaging detectors, STIX has two additional detectors: the coarse flare locator (CFL) and the background (BKG) detector, which ar…
Circumstellar emission of Cepheids across the instability strip: Mid-infrared observations with VLTI/MATISSE
Matter, A.; Smolec, R.; Lopez, B. +14 more
Context. The circumstellar envelopes (CSE) of Cepheids are still only poorly characterized despite their potential impact on the distance determination via both the period-luminosity relation and the parallax-of-pulsation method. Aims. This paper aims to investigate Galactic Cepheids across the instability strip in the mid-infrared with MATISSE/VL…
Three new hot hydrogen-deficient pre-white dwarfs
Werner, Klaus; Reindl, Nicole; Geier, Stephan +1 more
We have detected three new hydrogen-deficient (H < 0.001 mass fraction) pre-white dwarfs (WDs) with helium-dominated atmospheres. The first object is a relatively cool PG1159 star (effective temperature Teff = 72 000 K) that has the lowest surface gravity of any PG1159 star known (log g = 4.8). It is a PG1159 star in the earliest pre…
Resolving the mass transfer in the symbiotic recurrent nova T Coronae Borealis
Jorissen, A.; Planquart, L.; Van Winckel, H.
Context. T Coronæ Borealis (T CrB) is a symbiotic recurrent nova with an 80-year recurrence interval whose next eruption is imminent. Aims. We aim to resolve the accretion mechanism of the binary system governing the mass transfer during its super-active phase. Methods. Using phase-resolved high-resolution spectroscopy, we analyzed the zoo of spec…
MAGIS (Measuring Abundances of red super Giants with Infrared Spectroscopy) project: I. Establishment of an abundance analysis procedure for red supergiants and its evaluation with nearby stars
Kobayashi, Naoto; Matsunaga, Noriyuki; Kawakita, Hideyo +11 more
Context. Given their high luminosities (L ≳ 104 L⊙), red supergiants (RSGs) are good tracers of the chemical abundances of the young stellar population in the Milky Way and nearby galaxies. However, previous abundance analyses tailored to RSGs suffer some systematic uncertainties originating in, most notably, the synthesized …
Stereoscopic observations reveal coherent morphology and evolution of solar coronal loops
Peter, H.; Chitta, L. P.; Plaschke, F. +2 more
Coronal loops generally trace magnetic lines of force in the upper solar atmosphere. Understanding the loop morphology and its temporal evolution has implications for coronal heating models that rely on plasma heating due to reconnection at current sheets. Simultaneous observations of coronal loops from multiple vantage points are best suited for …
Coronal hole picoflare jets are progenitors of both fast and Alfvénic slow solar wind
Livi, S.; Peter, H.; Chitta, L. P. +19 more
Solar wind, classified by its bulk speed and the Alfvénic nature of its fluctuations, generates the heliosphere. The elusive physical processes responsible for the generation of the different types of this wind are a topic of active debate. Recent observations reveal intermittent jets, with kinetic energy in the picoflare range, emerging from dark…
The centimeter emission from planet-forming disks in Taurus
Pascucci, I.; Garufi, A.; Testi, L. +16 more
The last decade has witnessed remarkable advances in the characterization of the (sub-)millimeter emission from planet-forming disks. Conversely, the study of (sub-)centimeter emission has made more limited progress, to the point that only a few exceptional disk-bearing objects have been characterized in the centimeter regime. This work takes a br…