Search Publications
A critical evaluation of the elemental abundances and evolutionary status of 15 Vul (HD 189849): the first identification of an evolved Am star
Çay, M. Taşkın; Çay, İpek H.; Civelekler, Betül
Understanding the evolution of metallic-line (
New red supergiant stars in the other side of our Galaxy
Gao, Jian; Ren, Yi; Jiang, Biwei +3 more
Red supergiant stars (RSGs) are massive stars in a late stage of evolution, crucial for understanding stellar life cycles and Galactic structure. However, RSGs on the far side of our Galaxy have been underexplored due to observational challenges. In this study, we introduce a novel method and present a new catalogue comprising 474 RSGs situated on…
Unveiling the infrared excess of SIPS J2045-6332: evidence for a young stellar object with potential low-mass companion
Meisner, Aaron M.; Kirkpatrick, J. Davy; Burgasser, Adam J. +16 more
The Disc Detective project, a citizen science initiative, aims to identify circumstellar discs around stars by detecting objects with infrared (IR) excess using data from the Wide-field Infrared Survey Explorer (WISE). In this study, we investigate SIPS J2045-6332, a potential brown dwarf with significant IR excess in WISE and Two Micron All Sky S…
Machine learning-based identification of Gaia astrometric exoplanet orbits
Sahlmann, Johannes; Gómez, Pablo
The third Gaia data release (DR3) contains ~170 000 astrometric orbit solutions of two-body systems located within ~500 pc of the Sun. Determining component masses in these systems, in particular of stars hosting exoplanets, usually hinges on incorporating complementary observations in addition to the astrometry, e.g. spectroscopy and radial veloc…
The temporal and spatial variations of lithium abundance in the Galactic disc
Shi, Jianrong; Chen, Yuqin; Bi, Shaolan +6 more
This study investigates the temporal and spatial variations in lithium abundance within the Milky Way using a sample of 22 034 main-sequence turn-off (MSTO) stars and subgiants, characterized by precise stellar ages, 3D non-local thermodynamic equilibrium lithium abundances, and birth radii. Our results reveal a complex variation in lithium abunda…
X-ray timing and spectral characteristics of compact symmetric objects
Stalin, C. S.; Saikia, D. J.; Paliya, Vaidehi S. +1 more
Compact Symmetric Objects (CSOs) are a distinct category of jetted active galactic nuclei whose high-energy emission is not well understood. We examined the X-ray characteristics of 17 bona fide CSOs using observations from Chandra, XMM-Newton, and NuSTAR. Among the sources with XMM-Newton observations, we found two sources, J0713+4349 and J1326+3…
The Y dwarf population with HST: unlocking the secrets of our coolest neighbours - II. Parallaxes and proper motions
Bedin, Luigi R.; Bardalez Gagliuffi, Daniella C.; Albert, Loïc +1 more
We present astrometric results from a Hubble Space Telescope (HST) campaign aimed at determining precise distances for cold Y-type brown dwarfs. Combining observations from a dedicated HST/WFC3 programme with archival data, we derive astrometric solutions for 15 nearby Y dwarfs, by linking the high-precision relative astrometry from Hubble to the …
A comprehensive photometric and spectroscopic study of B-type stars in the open cluster NGC 6834
Baume, G.; Granada, A.; Aidelman, Y. J. +1 more
This study focuses on the open cluster NGC 6834. Despite being well-known, its primary parameters show considerable variation. As an intermediate-age cluster (50-80 million years), it is expected to host a prominent population of B-type stars, including numerous Be stars. Fifteen B-type variable stars have already been identified in the vicinity o…
Asteroseismic study of subgiants and giants of the open cluster M67 using Kepler/K2: expanded sample and precise masses
Vanderburg, Andrew; Li, Yaguang; Corsaro, Enrico +7 more
Sparked by the asteroseismic space revolution, ensemble studies have been used to produce empirical relations linking observed seismic properties and fundamental stellar properties. Cluster stars are particularly valuable because they have the same metallicity, distance, and age, thus reducing scatter to reveal smoother relations. We present the f…
Conducting high-frequency radio SETI searches using ALMA
Mason, Louisa A.; Garrett, Michael A.; Wandia, Kelvin +1 more
The Atacama Millimeter/Submillimeter Array (ALMA) remains unparalleled in sensitivity at radio frequencies above 35 GHz. In this paper, we explore ALMA's potential for narrow-band technosignature detection, considering factors such as the interferometer's undistorted field of view, signal dilution due to significant drift rates at high frequencies…