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A binary system in the S cluster close to the supermassive black hole Sagittarius A*

Eckart, Andreas; Zajaček, Michal; Labadie, Lucas +4 more

High-velocity stars and peculiar G objects orbit the central supermassive black hole (SMBH) Sagittarius A* (Sgr A*). Together, the G objects and high-velocity stars constitute the S cluster. In contrast with theoretical predictions, no binary system near Sgr A* has been identified. Here, we report the detection of a spectroscopic binary system in …

Long-term Doppler imaging of the star XX Trianguli indicates chaotic non-periodic dynamo

Strassmeier, K. G.; Weber, M.; Granzer, T. +1 more

Sunspots are the most well-known manifestations of solar magnetic fields and exhibit a range of phenomena related to the interior dynamo. Starspots are the direct analogs of sunspots on other stars but with the big observational restriction that we usually cannot resolve other star's surfaces. In this paper we employ an indirect surface imaging te…

Jupiter-like planets might be common in a low-density environment

D'Orazi, Valentina; Zurlo, Alice; Gratton, Raffaele +6 more

Radial velocity surveys suggest that the Solar System may be unusual and that Jupiter-like planets have a frequency < 20% around solar-type stars. However, they may be much more common in one of the closest associations in the solar neighbourhood. Young moving stellar groups are the best targets for direct imaging of exoplanets and four massive…

Phosphorus-rich stars with unusual abundances are challenging theoretical predictions

Masseron, Thomas; García-Hernández, D. A.; Zamora, Olga +4 more

Almost all chemical elements have been made by nucleosynthetic reactions in various kind of stars and have been accumulated along our cosmic history. Among those elements, the origin of phosphorus is of extreme interest because it is known to be essential for life such as we know on Earth. However, current models of (Galactic) chemical evolution u…