Search Publications
New interpretation of the two hard X-ray sources IGR J17503-2636 and IGR J17507-2647
Ponti, G.; Sidoli, L.; Esposito, P. +4 more
We report on the results of X-ray observations (XMM–Newton, INTEGRAL and Swift) of two hard X-ray sources, IGR J17503-2636 and IGR J17507-2647, whose nature is not fully elucidated in the literature. Three XMM–Newton observations covered the field of IGR J17503-2636, in 2020 and twice in 2023. The analysis of the two XMM–Newton observations perfor…
PAStar: A model for stellar surface from the Sun to active stars
Petralia, Antonino; Micela, Giuseppina; Maldonado, Jesús
Context. The characterisation of exoplanets requires a good description of the host star. Stellar activity acts as a source of noise, which can alter planet radii as derived from the transit depth or atmospheric characterisation. Aims. Here, we propose PAStar, a model to describe photospheric activity in the form of spots and faculae, which could …
Effects of the September 2014 coronal mass ejection chain in the inner Solar System and the response of the Martian ionosphere
Sánchez-Cano, B.; Harada, Y.; Ippolito, A.
Context. During September 2014, intense solar activity led to a number of coronal mass ejections (CMEs) propagating in the heliosphere. The strong perturbation in the interplanetary magnetic field and the remarkable enhancements in the energetic particle fluxes accelerated by the shock waves associated with the CMEs affected the environments of th…
3D projection analysis: Characterizing the morphological stability of nearby open clusters
Hu, Qingshun; Luo, Yangping; Li, Yuting +1 more
Context. The study of open cluster morphology is pivotal for exploring their formation and evolutionary processes. Aims. We manage to assess the morphological stability of 105 nearby open clusters within tidal radii on the X-Y, X-Z, and Y-Z planes of the heliocentric Cartesian coordinate system, utilizing member catalogs from the literature. Meanw…
A broadband X-ray view of the ultraluminous sources in the galaxies ESO 501–023 and IC 5052
Combi, J. A.; García, F.; Abaroa, L. +4 more
We report the results obtained from the analysis of XMM-Newton and NuSTAR observations of two ultraluminous X-ray sources (ULXs) located in the galaxies ESO 501–023 and IC 5052. To better understand their nature, we studied the spectral and timing behavior of these sources. We used spectral-timing techniques to investigate the presence of possible…
Emergence of magnetic flux sheets in the quiet Sun: I. Statistical properties
Guglielmino, S. L.; Ishikawa, R.; Fischer, C. E. +3 more
Context. Small-scale magnetic flux emergence in the quiet Sun is crucial for maintaining solar magnetic activity. On the smallest scales studied so far, namely within individual granules, two mechanisms have been identified: emergence in tiny magnetic loops and emergence in the form of magnetic flux sheets covering the granule. While there are abu…
KIC 4150611: A quadruply eclipsing heptuple star system with a g-mode period-spacing pattern: Asteroseismic modelling of the g-mode period-spacing pattern
Li, Gang; Aerts, Conny; Van Reeth, Timothy +7 more
Context. KIC 4150611 is a high-order (seventh-order) multiple composed of a triple system with: a F1V primary (Aa), which is eclipsed on a 94.2 d period by a tight binary composed of two K/M dwarfs (Ab1 and Ab2) that also eclipse each other; an eccentric, eclipsing binary composed of two G stars (Ba and Bb); and another faint eclipsing binary comp…
MINCE: III. Detailed chemical analysis of the UVES sample
Hansen, C. J.; Bonifacio, P.; Caffau, E. +14 more
Context. The Measuring at Intermediate Metallicity Neutron-Capture Elements (MINCE) project aims to provide high-quality neutron-capture abundances measurements for several hundred stars at an intermediate metallicity of ‑2.5 < [Fe/H] < ‑1.5. This project will shed light on the origin of the neutron-capture elements and the chemical enrichme…
A Be star that turned bright and blue during a major outburst
Wang, Wei; Rivinius, Thomas; Baade, Dietrich +16 more
Context. Classical Be stars are rapidly rotating B-type stars exhibiting Balmer emission lines originating from circumstellar Keplerian gaseous disks, which likely form through episodic mass-ejection events. The currently favored model for Be star disks is the viscous decretion disk (VDD) model. However, the mechanism behind the mass ejection proc…
Searching for Galactic red supergiants with Gaia RVS spectra
Yang, Ming; Ren, Yi; Jiang, Biwei +2 more
Red supergiants (RSGs) are essential to understanding the evolution and the contribution to the interstellar medium of massive stars. However, the number of identified RSGs within the Milky Way is still limited, mainly due to the difficulty of measuring stellar extinction and distance. The release of approximately one million RVS spectra in Gaia D…