30,001 datasets found

Close encounters of stars to the Sun could affect life on Earth through gravitational perturbations of comets in the Oort cloud or exposure to ionizing radiation. By integrating...

Massive binaries play an important role in fields ranging from gravitational- wave astronomy to stellar evolution. We provide several lines of evidence that classical OBe stars...

We present the results of optical and near-IR spectroscopy and multicolor photometry of the emission-line star MWC 645, which exhibits the B[e] phenomenon. The presence of...

A long-term (1995-2016) survey for novae in the nearby Andromeda galaxy (M31) was conducted as part of the Research-Based Science Education initiative. During the course of the...

It is known that the blazar jet emissions are dominated by nonthermal radiation, while the accretion disk jets are normally dominated by thermal emission. In this work,...

We report the discovery of Tucana B, an isolated ultra-faint dwarf galaxy at a distance of D=1.4Mpc. Tucana B was found during a search for ultra-faint satellite companions to...

The culmination of solar cycle 24 by the end of 2019 has created the opportunity to compare the differing properties of coronal mass ejections (CMEs) between two whole solar...

We examine the degree of energy equipartition in nine Galactic globular clusters using proper motions measured with the Hubble Space Telescope. For most clusters in the sample,...

A search for extremely slow (Vsw<300km/s) solar winds (ESSWs) at 1au has been conducted using hourly average solar wind data from 1963 through 2021. 297 ESSW events were...

Recent analyses of Gaia data have resulted in the identification of new stellar structures, including a new class of extended stellar filaments called stellar "strings," first...

We present the first results from our ongoing project to study extremely low-mass (ELM) white dwarfs (WDs) (M<~0.3M{sun}) with the Large Sky Area Multi-Object Fiber...

We have computed obscured active galactic nuclei (AGN) redshifts using the XZ method, adopting a broad treatment in which we employed a wide-ranging data set and worked...

Dynamical models for 673 galaxies at z=0.6-1.0 with spatially resolved (long-slit) stellar kinematic data from LEGA-C are used to calibrate virial mass estimates defined as...

HD-166620 was recently identified as a Maunder minimum candidate based on nearly 50 years of CaII H and K activity data from Mount Wilson and Keck HIRES. These data showed clear...

Changing-look active galactic nucleus NGC4151, which has attracted a lot of attention, is undergoing the second dramatic outburst stage in its evolutionary history. To...

Surrounding the Milky Way (MW) is the circumgalactic medium (CGM), an extended reservoir of hot gas that has significant implications for the evolution of the MW. We used the...

Historically, FU Orionis-type stars are low-mass, pre-main-sequence stars. The members of this class experience powerful accretion outbursts and remain in an enhanced accretion...

We present detailed criteria for the classification of subtypes of B-type supergiants and apply them to 97 supergiants chosen manually from the LAMOST DR5 data set. We obtained...

Studying the physical and chemical properties of cold and dense molecular clouds is crucial for the understanding of how stars form. Under the typical conditions of infrared...

The accuracy in determining the spatial-kinematical parameters of open clusters makes them ideal tracers of the Galactic structure. Young open clusters (YOCs) are the main...