Search Publications
TITANS metal-poor reference stars. II. Red giants and CEMP stars
Valentini, M.; Chiappini, C.; Jorissen, A. +6 more
Context. Representative samples of F-, G-, K-type stars located outside of the solar neighbourhood have started to become available in spectroscopic surveys. The fraction of metal-poor ([Fe/H] ≲ −0.8 dex) giants becomes increasingly relevant towards greater distances. In metal-poor stars, effective temperatures (Teff) based on local the…
Evidence for non-thermal X-ray emission from the double Wolf-Rayet colliding-wind binary Apep
Altamirano, D.; del Palacio, S.; García, F. +5 more
Context. Massive colliding-wind binaries (CWBs) can be non-thermal sources. The emission produced in their wind-collision region (WCR) encodes information of both the shock properties and the relativistic electrons accelerated in them. The recently discovered system Apep, a unique massive system hosting two Wolf-Rayet stars, is the most powerful s…
Small-scale loops heated to transition region temperatures and their chromospheric signatures in the simulated solar atmosphere
Leenaarts, J.; Danilovic, S.; Rempel, M. +2 more
Context. Recent observations have revealed loop-like structures at very small scales visible in observables that sample the transition region (TR) and even coronal temperatures. These structures are referred to as either `unresolved fine structures', `dynamic cool loops', `miniature hot loops' or `campfires' depending on the observables in which t…
TOI-1416: A system with a super-Earth planet with a 1.07 d period
Fridlund, M.; Pallé, E.; Guenther, E. W. +49 more
TOI-1416 (BD+42 2504, HIP 70705) is a V =10 late G- or early K-type dwarf star. TESS detected transits in its Sectors 16, 23, and 50 with a depth of about 455 ppm and a period of 1.07 days. Radial velocities (RVs) confirm the presence of the transiting planet TOI-1416 b, which has a mass of 3.48 ± 0.47 M⊕ and a radius of 1.62 ± 0.08 R
The young mini-Neptune HD 207496b that is either a naked core or on the verge of becoming one
Deleuil, M.; Winn, J. N.; Adibekyan, V. +39 more
Aims: We report the discovery and characterisation of the transiting mini-Neptune HD 207496 b (TOI-1099) as part of a large programme that aims to characterise naked core planets.
Methods: We obtained HARPS spectroscopic observations, one ground-based transit, and high-resolution imaging which we combined with the TESS photometry to conf…
Hint of an exocomet transit in the CHEOPS light curve of HD 172555
Alonso, R.; Deleuil, M.; Erikson, A. +72 more
HD 172555 is a young (~20 Myr) A7V star surrounded by a 10 au wide debris disk suspected to be replenished partly by collisions between large planetesimals. Small evaporating transiting bodies, that is exocomets, have also been detected in this system by spectroscopy. After β Pictoris, this is another example of a system possibly witnessing a phas…
In-flight radiometric calibration of the Metis Visible Light channel using stars and comparison with STEREO-A/COR2 data
Heinzel, P.; Sasso, C.; Romoli, M. +45 more
Context. We present the results for the in-flight radiometric calibration performed for the Visible Light (VL) channel of the Metis coronagraph on board Solar Orbiter.
Aims: The radiometric calibration is a fundamental step in building the official pipeline of the instrument, devoted to producing the calibrated data in physical units (L2 data…
Observing the onset of the accretion wake in Vela X-1
Santangelo, A.; Grinberg, V.; Kretschmar, P. +7 more
High-mass X-ray binaries (HMXBs) offer a unique opportunity to investigate accretion onto compact objects and the wind structure in massive stars. A key source for such studies is the bright neutron star HMXB Vela X-1 whose convenient physical and orbital parameters facilitate analyses and in particular enable studies of the wind structure in HMXB…
Accretion in the recurrent nova T CrB: Linking the superactive state to the predicted outburst
Zamanov, R.; Marchev, D.; Semkov, E. +6 more
Context. T CrB (NOVA CrB 1946) is a famous recurrent nova with a recurrence timescale of 80 years.
Aims: We aim to estimate the colours, luminosity, and mass-accretion rate for T CrB (NOVA CrB 1946) during and after the superactive state.
Methods: We performed and analysed UBV photometry of the recurrent nova T CrB.
Results: For the…
Direct assessment of SDO/HMI helioseismology of active regions on the Sun's far side using SO/PHI magnetograms
Schmidt, W.; Woch, J.; Solanki, S. K. +47 more
Context. Earth-side observations of solar p modes can be used to image and monitor magnetic activity on the Sun's far side. In this work, we use magnetograms of the far side obtained by the Polarimetric and Helioseismic Imager (PHI) on board Solar Orbiter (SO) to directly assess the validity of far-side helioseismic holography for the first time. …