Search Publications
Quantitative spectroscopy of late O-type main-sequence stars with a hybrid non-LTE method
Butler, K.; Przybilla, N.; Aschenbrenner, P.
Context. Late O-type stars at luminosities log L/L⊙ ≲ 5.2 show weak winds with mass-loss rates lower than 10−8 M⊙ yr−1. This implies that, unlike their more massive and more luminous siblings, their photospheric layers are not strongly affected by the stellar wind.
Aims: A hybrid non-local thermodyn…
Evolution of dynamic fibrils from the cooler chromosphere to the hotter corona
Teriaca, Luca; Solanki, Sami K.; Long, David M. +17 more
Dynamic fibrils (DFs) are commonly observed chromospheric features in solar active regions. Recent observations from the Extreme Ultraviolet Imager (EUI) aboard the Solar Orbiter have revealed unambiguous signatures of DFs at the coronal base in extreme ultraviolet (EUV) emission. However, it remains unclear if the DFs detected in the EUV are link…
TOI-1736 and TOI-2141: Two systems including sub-Neptunes around solar analogs revealed by TESS and SOPHIE
Deleuil, M.; Moutou, C.; Winn, J. N. +32 more
Planetary systems around solar analogs inform us about how planets form and evolve in Solar System-like environments. We report the detection and characterization of two planetary systems around the solar analogs TOI-1736 and TOI-2141 using TESS photometry data and spectroscopic data obtained with the SOPHIE instrument on the 1.93 m telescope at t…
Benchmarking Gaia DR3 Apsis with the Hyades and Pleiades open clusters
Brandner, Wolfgang; Calissendorff, Per; Kopytova, Taisiya
Context. The Gaia astrophysical parameters inference system (Apsis) provides astrophysical parameter estimates for several to hundreds of millions of stars.
Aims: We aim to benchmark Gaia DR3 Apsis.
Methods: We compiled approximately 1500 bona fide single stars in the Hyades and Pleiades open clusters for validation of PARSEC isochrones,…
A neutron star candidate in the long-period binary 56 UMa
Jorissen, A.; Verschuur, G. L.; Schmelz, J. T. +6 more
Context. 56 UMa is a wide binary system that contains a chemically peculiar red giant and a faint companion. Due to its surface chemical abundances, the red giant was classified as a barium (Ba) star. This implies that the companion has to be a white dwarf, since Ba stars form when mass is transferred to them from an s-process rich Asymptotic Gian…
Wide binaries demonstrate the consistency of rotational evolution between open cluster and field stars
Gruner, D.; Barnes, S. A.; Janes, K. A.
Context. Gyrochronology enables the derivation of ages of late-type main sequence stars based on their rotation periods and a mass proxy, such as color. It has been explored in open clusters, but a connection to field stars has yet to be successfully established.
Aims: We explore the rotation rates of wide binaries, representing enlightening …
Asteroseismic age constraints on the open cluster NGC 2477 using oscillating stars identified with TESS FFI
Creevey, O. L.; Palakkatharappil, D. B.
Context. Asteroseismology is one of the few methods to derive ages of individual stars due to the high precision of their observations. Isochrone fitting is a powerful alternative method for deriving ages by studying clusters of stars. Pulsating stars in clusters should therefore allow for detailed studies of the stellar models.
Aims: Our obj…
Multipoint study of the energy release and transport in the 28 March 2022, M4 flare using STIX, EUI, and AIA during the first Solar Orbiter nominal mission perihelion
Krucker, Säm; Veronig, Astrid M.; Dissauer, Karin +8 more
Context. The Spectrometer Telescope for Imaging X-rays (STIX) on board Solar Orbiter enables exciting multipoint studies of energy release and transport in solar flares by observing the Sun from many different distances and vantage points out of the Sun-Earth line.
Aims: We present a case study of an M4-class flare that occurred on 28 March 2…
The VISCACHA survey. VIII. Chemical evolution history of the Small Magellanic Cloud west halo clusters
Minniti, D.; Bica, E.; Maia, F. +12 more
The chemical evolution history of the Small Magellanic Cloud (SMC) has been a matter of debate for decades. The challenges in understanding the SMC chemical evolution are related to a very slow star formation rate (SFR) combined with bursts triggered by the multiple interactions between the SMC and the Large Magellanic Cloud, a significant (∼0.5 d…
The structural properties of multiple populations in the dynamically young globular cluster NGC 2419
Vesperini, Enrico; Cadelano, Mario; Dalessandro, Emanuele +3 more
NGC 2419 is likely the globular cluster (GC) with the lowest dynamical age in the Galaxy. This makes it an extremely interesting target for studying the properties of its multiple populations (MPs), as they are likely to have been affected only modestly by long-term dynamical evolution effects. Here we present for the first time a detailed analysi…