太阳与恒星天体物理
Stellar rotation has long been recognized as important to the evolution of stars, by virtue of the chemical mixing it can induce and how it interacts with binary mass transfer. Binary interaction and rapid rotation are both common in…
We present centimeter continuum observations of seven high luminosity massive protostars and their surrounding sources in regions with multiple targets, as part of the SOFIA Massive (SOMA) Star Formation Survey. With data from the Very…
We aim to identify the cluster members, estimate cluster properties, study the dynamical state of the clusters as a function of mass, trace the existence of dynamical effects in massive stars, and check for spatial patterns of members in…
Two main formation routes have been proposed for interstellar complex organic molecules (iCOMs): on dust grain surfaces and in the gas phase. Observing such molecules in protostellar outflow shock regions - provided that their ages are…
We present an atlas of full-scan spectra from the Short-Wavelength Spectrometer (SWS) aboard the Infrared Space Observatory (ISO) after reprocessing and improving an earlier version published 22 years ago. The SWS spectra cover the…
Recent observations have revealed a surprisingly large fraction of hydrogen-rich supernovae (SNe) interacting with dense confined circumstellar material (CSM), whose origin is heavily debated. Exploiting our recent implementation of a…
We present phosphorus abundance measurements for a total of 102 giant stars, including 82 stars in 24 open clusters and 20 Cepheids, based on high-resolution near-infrared spectra obtained with GIANO-B. Evolution of phosphorus abundance,…
Through three-dimensional MHD simulations, we have uncovered a kind of fast coronal wave originating from both ends of a current sheet (CS) during a solar eruption. These waves are observed to appear near the top and bottom ends of the…
Aims: Studying the dynamical evolution of young clusters is crucial for a more general understanding of the star formation process. Methods: We took spectra of >600 candidate pre-main sequence (PMS) stars in several nearby young clusters…
We present a comprehensive photometric, spectroscopic, and polarimetric study of the intermediate polar (IP) 1RXS J080114.6-462324, using observations from the South African Astronomical Observatory (SAAO) 1.0-m and 1.9-m telescopes and the…
Local particle acceleration in the shock sheath region formed during the interaction between multiple coronal mass ejections (CMEs) is a complicated process that is still under investigation. On March 23, 2024, the successive eruption of…
The classification of X-ray binaries into high- and low-mass types has historically lacked a unified, data-driven quantitative criterion, and large-scale statistical studies of the donor star population have been limited. In this work, we…
Magnetic reconnection is a multiscale phenomenon where fluid- and particle-scale processes interact. The particle-in-cell (PIC) method, capable of resolving kinetic (particle-scale) physics, is extensively used to study the kinetic effects…
Tracing the water snowline in low-mass young stellar objects (YSOs) is important because dust grain growth is promoted and the chemical composition varies at the water snowline, which influences planet formation and its properties. In…
This study investigates the gravitational waves (GWs) generated by the emergence of magnetic flux tubes in the solar convection zone. We focus on the upward buoyancy of magnetic flux tubes, which leads to significant magnetic activity and…
Gyrochronology, a method for dating aged field stars ($\gtrsim$ a few Gyr) based on their rotation rate, has recently been shown to fail for many stars older than the sun. The explanation most often put forth is that a shutdown or mode…
The study presents a detailed spectroscopic analysis of the planetary nebulae (PNe) NGC~2392 and NGC~4361 using optical spectra obtained from the 2-m Himalayan Chandra Telescope (HCT) and mid-infrared spectra from archival \textit{Spitzer}…
Massive stars can have extreme effects on their environments from local to galactic scales. While O star multiplicity has been studied over a broad separation range (to the point where absolute masses of these systems have been determined…
Radial velocity searches may lead to detection of exoplanets at large orbital separations only if long-enough time-series of data are available. Therefore publication of precise measurements collected in the past is very valuable even if…
Supernova 1987A was the closest supernova event to be observed in nearly 400 years. The outflowing ejecta from the explosion continues to interact with extended circumstellar material and with the equatorial ring (ER) in the triple ring…