Search Publications
Recurrent X-ray flares of the black hole candidate in the globular cluster RZ 2109 in NGC 4472
Lodato, G.; Salvaterra, R.; Tiengo, A. +7 more
We report the systematic analysis of the X-ray observations of the ultraluminous X-ray source
FSR 1776: A new globular cluster in the Galactic bulge?
Minniti, D.; Saito, R. K.; Fernández-Trincado, J. G. +6 more
Context. Recent near-IR surveys have uncovered a plethora of new globular cluster (GC) candidates towards the Milky Way bulge. These new candidates need to be confirmed as real GCs and properly characterised.
Aims: We investigate the physical nature of FSR 1776, a very interesting star cluster projected towards the Galactic bulge. This object…
The GAPS programme at TNG. XXXIV. Activity-rotation, flux-flux relationships, and active-region evolution through stellar age
Baratella, M.; Mallonn, M.; Scandariato, G. +26 more
Context. Active-region evolution plays an important role in the generation and variability of magnetic fields on the surface of lower main sequence stars. However, determining the lifetime of active-region growth and decay as well as their evolution is a complex task. Most previous studies of this phenomenon are based on optical light curves, whil…
Validation and atmospheric exploration of the sub-Neptune TOI-2136b around a nearby M3 dwarf
Kuzuhara, M.; Tamura, M.; Kudo, T. +51 more
Context. The NASA space telescope TESS is currently in the extended mission of its all-sky search for new transiting planets. Of the thousands of candidates that TESS is expected to deliver, transiting planets orbiting nearby M dwarfs are particularly interesting targets since they provide a great opportunity to characterize their atmospheres by t…
Lithium, masses, and kinematics of young Galactic dwarf and giant stars with extreme [α/Fe] ratios
Charbonnel, C.; Prantzos, N.; Borisov, S.
Context. Recent spectroscopic explorations of large Galactic stellar samples stars have revealed the existence of red giants with [α/Fe] ratios that are anomalously high, given their relatively young ages.
Aims: We revisit the GALAH DR3 survey to look for both dwarf and giant stars with extreme [α/Fe] ratios, that is, the upper 1% in the [α/F…
Li-rich and super Li-rich giants produced by element diffusion
Shi, Jianrong; Lü, Guoliang; Zhu, Chunhua +4 more
Context. About 0.2−2% of giant stars are Li rich, that is to say their lithium abundance (A(Li)) is higher than 1.5 dex. Nearly 6% of these Li-rich giant stars are super Li rich, with an A(Li) exceeding 3.2 dex. Meanwhile, the formation mechanism of these Li-rich and super Li-rich giants is still under debate.
Aims: Considering the compact He…
SRG/ART-XC discovery of SRGA J204318.2+443815: Towards the complete population of faint X-ray pulsars
Yao, Y.; Kulkarni, S. R.; Bikmaev, I. F. +19 more
We report the discovery of the new long-period X-ray pulsar SRGA J204318.2+443815/SRGe J204319.0+443820 in a Be binary system. The source was found in the second all-sky survey by the Mikhail Pavlinsky ART-XC telescope on board the SRG mission. The follow-up observations with XMM-Newton, NICER, and NuSTAR allowed us to discover a strong coherent s…
Pulsating hydrogen-deficient white dwarfs and pre-white dwarfs observed with TESS. V. Discovery of two new DBV pulsators, WDJ152738.4−450207.4 and WD 1708−871, and asteroseismology of the already known DBV stars PG 1351+489, EC 20058−5234, and EC 04207−4748
Kepler, S. O.; Hermes, J. J.; Althaus, L. G. +9 more
Context. The TESS space mission has recently demonstrated its great potential to discover new pulsating white dwarf and pre-white dwarf stars, and to detect periodicities with high precision in already known white-dwarf pulsators.
Aims: We report the discovery of two new pulsating He-rich atmosphere white dwarfs (DBVs) and present a detailed …
Radial Velocity Survey for Planets around Young stars (RVSPY). Target characterisation and high-cadence survey
Trifonov, Trifon; Henning, Thomas; Reffert, Sabine +15 more
Context. The occurrence rate and period distribution of (giant) planets around young stars is still not as well constrained as for older main-sequence stars. This is mostly due to the intrinsic activity-related complications and the avoidance of young stars in many large planet search programmes. Yet, dynamical restructuring processes in planetary…
Fast time optical variability in Be/X-ray binaries. Pulsation and rotation
Reig, P.; Fabregat, J.
Context. Classical Be stars, regardless of spectral subtype, display multi-periodic light modulations in the frequency range 0.1-12 c d−1 when observed with a high cadence and a long duration. This behavior is attributed to non-radial pulsations and/or the rotation of the Be star. A similar study on the optical counterparts to Be/X-ray …