太阳与恒星天体物理
The thermally pulsating asymptotic giant branch (TP-AGB) phase plays a key role in the evolution of low- to intermediate-mass stars, driving mass loss that influences their final stages and contributes to galactic chemical enrichment.…
[Abbreviated] Context. Solar twins, stars whose stellar parameters (Teff, log g, and [M/H]) are very close to the Solar ones, offer a unique opportunity to investigate Galactic archaeology with very high accuracy and precision. However,…
Star formation is governed by multiple physical processes, making it inherently complicated. One excellent example is the Canis Major OB1/R1 Association, whose complex history of star formation is related to different episodes. Three…
The alignment between the radio-based International Celestial Reference Frame (ICRF) and the optical Gaia Celestial Reference Frame (Gaia-CRF) is critical for multi-waveband astronomy, yet systematic offsets at the optical bright end (G<13)…
Determining how long circumstellar disks last is key to understanding the timescale of planet formation. Typically, this is done by measuring the fraction of young stars with infrared-excess, a sign of circumstellar material, in stellar…
Latitude distribution of stellar magnetic activity is not well constrained by observations, despite its importance for a better understanding of stellar dynamos. We aim to obtain an accurate reconstruction of the surface spot distribution…
Dipolar (l=1) mixed modes revealed surprisingly weak differential rotation between the core and the envelope of evolved solar-like stars. Quadrupolar (l=2) mixed modes also contain information on the internal dynamics, but are very rarely…
With the ever faster cadence of untargeted surveys of the sky, the supernova (SN) community will capture in the coming years a growing number of shock breakouts in red-supergiant (RSG) stars. Expecting a high frequency of breakouts within…
Polycyclic Aromatic Hydrocarbons (PAHs) constitute a significant fraction of the Universe's carbon budget, playing a key role in the cosmic carbon cycle and dominating the mid-infrared spectra of astrophysical environments in which they…
The Energetic Particle Radiation Environment Model (EPREM) solves the focused transport equation (FTE) on a Lagrangian grid in a frame co-moving with the solar wind plasma and simulates the acceleration and transport of solar energetic…
We present GalRSG, a new catalogue of 227 Galactic Red Supergiants in the Scutum-Crux region, which provides a nearly coeval and co-distant sample, target of a long-term, panchromatic, high-cadence photometric monitoring campaign aimed at…
We investigate whether the first discovered fluorine-rich CEMP-no star, CS 29498$-$043, can be explained by a very metal-poor rotating massive star. We consider single rotating stellar models of 20 $M_{\odot}$ at a metallicity of $Z =…
Context. Long-period Wolf-Rayet (WR) star binaries produced by mass transfer are predicted to be abundant, but are observationally rare. This yields constraints on the evolution of initially wide O star binaries, including those potentially…
The phosphorus abundance distribution in field stars as a function of metallicity reveals a complex pattern. The LTE data for [P/Fe] in the low-metallicity range are sparse and scattered around [P/Fe]~ 0 dex. Near [Fe/H]~ -2 dex, the…
Time-resolved optical photometry, complemented by TESS data and long-term survey light curves, reveals that the transient object CRTS SSS100505 J093417-174421 is an eclipsing novalike cataclysmic variable of the VY~Scl subtype, with an…
We present optical and near-infrared (NIR) photometric and spectroscopic observations of the Type II supernova SN 2023ixf spanning 150 to 750 days, combined with published early-time optical and infrared photometry, and JWST NIRSpec and…
The R Coronae Borealis (RCB) Star, V854 Cen, was not discovered until the 1980's even though it is 7th magnitude at maximum light. This is because it was in a faint state due to the presence of thick circumstellar dust clouds for nearly a…
An important goal of the disk instability model is to explain the superhump phenomenon. Superhumps are features found in the light curves of binary systems, characterized by a period slightly different from the binary orbital period. In…
We present a ground-based time-series photometric study of stellar variability in four intermediate- to old-age open clusters NGC 2192, NGC 2266, NGC 2509, and IC 1369 based on high-cadence Cousins R-band observations obtained with the 0.6…
The modified Castor, Abbott, and Klein (m-CAK) theory predicts different wind regimes based on the line force parameter for changes in ionization ($\delta$) and the rotation parameter ($\Omega$). Stationary hydrodynamic studies have…