Search Publications
Evolution of the critical torus instability height and coronal mass ejection likelihood in solar active regions
O'Kane, Jennifer; James, Alexander W.; Williams, David R.
Aims: Working towards improved space weather predictions, we aim to quantify how the critical height at which the torus instability drives coronal mass ejections (CMEs) varies over time in a sample of solar active regions.
Methods: We model the coronal magnetic fields of 42 active regions and quantify the critical height at their central…
Establishing the accuracy of asteroseismic mass and radius estimates of giant stars. III. KIC 4054905, an eclipsing binary with two 10 Gyr thick disk RGB stars
Grundahl, F.; Lund, M. N.; Miglio, A. +16 more
Context. Eclipsing binary stars with an oscillating giant component allow accurate stellar parameters to be derived and asteroseismic methods to be tested and calibrated. To this aim, suitable systems need to be firstly identified and secondly measured precisely and accurately. KIC 4054905 is one such system, which has been identified, but with me…
Deuteration of c-C3H2 towards the pre-stellar core L1544
Caselli, P.; Spezzano, S.; Sipilä, O. +7 more
Context. In the centre of pre-stellar cores, the deuterium fractionation is enhanced due to the cold temperatures and high densities. Therefore, the chemistry of deuterated molecules can be used to probe the evolution and the kinematics in the earliest stages of star formation.
Aims: We analyse emission maps of cyclopropenylidene, c-C3
Searching for anomalous microwave emission in nearby galaxies. K-band observations with the Sardinia Radio Telescope
Bianchi, S.; Madden, S. C.; Galliano, F. +9 more
Aims: We observed four nearby spiral galaxies (NGC 3627, NGC 4254, NGC 4736, and NGC 5055) in the K band with the 64-m Sardinia Radio Telescope, with the aim of detecting anomalous microwave emission (AME), a radiation component presumably due to spinning dust grains, which has been observed thus far in the Milky Way and only in a handful of …
THA 15−31: Discovery with VLT/X-shooter and Swift/UVOT of a new symbiotic star of the accreting-only variety
Masetti, N.; Munari, U.; Alcalá, J. M. +4 more
We report the discovery and characterization of a new symbiotic star of the accreting-only variety, which we observed in the optical/near-infrared (NIR) with VLT/X-shooter and in the X-rays/ultraviolet with Swift/UVOT+XRT. The new symbiotic star, THA 15−31, was previously described as a pre-main sequence star belonging to the Lupus 3 association. …
SRGA J124404.1-632232/SRGU J124403.8-632231: New X-ray pulsar discovered in the all-sky survey by the SRG
Haberl, F.; Santangelo, A.; Gromadzki, M. +12 more
Ongoing all-sky surveys by the eROSITA and the Mikhail Pavlinsky ART-XC telescopes on board the Spectrum-Roentgen-Gamma (SRG) mission have already revealed over a million of X-ray sources. One of them, SRGA J124404.1-632232/SRGU J124403.8-632231, was detected as a new source in the third (of the planned eight) consecutive X-ray surveys by ART-XC. …
Metallicity of the globular cluster NGC 6388 based on high-resolution spectra of more than 160 giant stars
Bragaglia, Angela; Carretta, Eugenio
News from Gaia on σ Ori E: A case study for the wind magnetic braking process
Eggenberger, P.; Meynet, G.; Mowlavi, N. +8 more
Context.σ Ori E, a massive helium B-type star, shows high surface rotation and a strong surface magnetic field, potentially challenging the process of wind magnetic braking.
Aims: The Gaia satellite provides an accurate distance to σ Ori E and confirms its membership to the σ Ori cluster. We account for these two key pieces of information in …
Superflares on solar-like stars. A new method for identifying the true flare sources in photometric surveys
Solanki, S. K.; Shapiro, A. I.; Usoskin, I. +5 more
Context. Over the past years, thousands of stellar flares have been detected by harvesting data from large photometric surveys. These detections, however, do not account for potential sources of contamination such as background stars or small Solar System objects appearing in the same aperture as the primary target.
Aims: We present a new met…
Accretion variability in RU Lup
Ray, T. P.; Natta, A.; Caratti o Garatti, A. +2 more
Context. The process of accretion in classical T Tauri stars (CTTSs) has been observed to vary on different timescales. Studying this variability is vital to understanding a star's evolution and provides insight into the complex processes at work within, including sources of the veiling present. Understanding the dichotomy between continuum veilin…