Search Publications
HR 10 as seen by CHEOPS and TESS: Revealing δ Scuti pulsations, granulation-like signal and hint for transients
Alonso, R.; Deleuil, M.; Erikson, A. +78 more
Context. HR 10 has only recently been identified as a binary system. Previously thought to be an A-type shell star, it appears that both components are fast-rotating A-type stars, each presenting a circumstellar envelope. Although showing complex photometric variability, spectroscopic observations of the metallic absorption lines reveal variation …
Unveiling very young O stars. Two Galactic O2V((f*))z in Westerlund 2
Roman-Lopes, A.
Context. O-type stars are known to significantly contribute to both the dynamics and evolution of galaxies. Massive and luminous, they probably control and regulate the galaxies star formation rates. The stellar feedback generated by such cosmic beasts can strongly affect the local star formation rate, with effects in the current (and future) gene…
The corona of a fully convective star with a near-polar flare
Stelzer, B.; Poppenhäger, K.; Ilin, E. +1 more
Context. In 2020, the Transiting Exoplanet Survey Satellite (TESS) observed a rapidly rotating M7 dwarf, TIC 277539431, producing a flare at 81° latitude, the highest latitude flare located to date. This is in stark contrast to solar flares that occur much closer to the equator, typically below 30°. The mechanisms that allow flares at high latitud…
Variation in the intensity ratio at each wavelength point of the Si IV 1394/1403 Å lines: Spectral diagnostics of a bifurcated eruption
Xu, Zhe; Xue, Zhike; Yan, Xiaoli +3 more
Aims. This study aims to investigate the deviation of the intensity ratio of the Si IV 1394 Å and 1403 Å emission lines from the expected value of 2 in the optically thin regime, as has been observed in many recent studies. Methods. We analyzed the integrated intensity ratio (R) and the wavelength-dependent ratio (r(Δλ)) in a small bifurcated erup…
The true age of multi-planet host star HD 110067: Or: Don't be fooled by K0V-type stars
Fridlund, Malcolm; Jack, Dennis; Schröder, Klaus-Peter +3 more
HD 110067 is a near (d = 32.22 pc, V = 8.43 mag) K0V star in Coma Ber that was recently discovered to host a six-planet system in stable resonances. The star has a very old age of 8+/‑4 Gyr. However, by the nature of the respective evolution tracks (i.e. with masses of 0.78...0.85 M⊙), which run parallel to the zero-age main sequence fo…
The AMBRE Project: Lead abundance in Galactic stars
Recio-Blanco, A.; de Laverny, P.; Contursi, G. +4 more
Context. The chemical evolution of neutron capture elements in the Milky Way is still a matter of debate. Although more and more studies investigate their chemical behaviour, there is still a lack of a significant large sample of abundances of a key heavy element: lead. Aims. Lead is the final product of the s-process nucleosynthesis channel and i…
European VLBI Network observations of the peculiar radio source 4C 35.06 overlapping with a compact group of nine galaxies
An, T.; Gabányi, K. É.; Frey, S. +8 more
Context. According to the hierarchical structure formation model, brightest cluster galaxies (BCGs) evolve into the most luminous and massive galaxies in the Universe through multiple merger events. The peculiar radio source 4C 35.06 is located at the core of the galaxy cluster Abell 407, overlapping with a compact group of nine galaxies. Low-freq…
Extreme-emission-line galaxies in the MUSE Hubble Ultra Deep Field Survey
Vílchez, J. M.; Iglesias-Páramo, J.; Arroyo-Polonio, A. +1 more
Aims: We aim to apply a methodology to build a sample of extreme-emission-line galaxies (EELGs) using integral field spectroscopy data. In this work, we followed the spectroscopic criteria corresponding to EELG selection and used the MUSE Hubble Ultra-Deep Field Survey, which includes the deepest spectroscopic survey ever performed.
Meth…
Multiwavelength identification of millisecond pulsar candidates in the Galactic bulge
Kerr, M.; Calore, F.; Schinzel, F. K. +4 more
Context. The existence of a population of millisecond pulsars in the Galactic bulge is supported, along with other evidence, by the Fermi GeV excess, an anomalous γ-ray emission detected almost 15 years ago in the direction of the Galactic center. However, radio surveys searching for pulsations have not yet revealed bulge millisecond pulsars. Aims…
Unveiling the short and faint X-ray transient nature of IGR J17419–2802
Sidoli, L.; Sguera, V.
We report new X-ray results from the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL), Swift, Chandra, and XMM–Newton observations of the hitherto poorly studied unidentified X-ray transient IGR J17419‑2802. We studied in detail the temporal, spectral, and energetic properties of three hard X-ray outbursts detected above 20 keV by INTEGR…