988 datasets found

The physical properties of transiting exoplanets are connected with the physical properties of their host stars. We present a homogeneous spectroscopic analysis based on the...

White dwarfs are excellent research laboratories as they reach temperatures, pressures, and magnetic fields that are unattainable on Earth. To better understand how these three...

We measure abundances of 12 elements (Na, Mg, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni) in a sample of 86 metal-poor (-2<~[Fe/H]<~-1) subgiant stars in the solar...

We used the Immersion GRating Infrared Spectrometer (IGRINS) to determine fundamental parameters for 61 K- and M-type young stellar objects (YSOs) located in the Ophiuchus and...

Mass loss in red supergiants (RSGs) is generally recognized to be episodic, but mass-loss prescriptions fail to reflect this. Evolutionary models show that the total amount of...

A total of 222 hot subdwarf stars were identified with LAMOST DR8 spectra, among which 131 stars show composite spectra and have been decomposed, while 91 stars present...

Fast yellow pulsating supergiants (FYPS) are a recently discovered class of evolved massive pulsators. As candidate supergiant objects, and one of the few classes of pulsating...

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...

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...

In this work, six convolutional neural networks (CNNs) have been trained based on 15638 superflare candidates on solar-type stars, which are collected from the three years of...

White dwarf (WD) stars evolve simply and predictably, making them reliable age indicators. However, self-consistent validation of the methods for determining WD total ages has...

We present the discovery of 17 double white dwarf (WD) binaries from our ongoing search for extremely low mass (ELM) <0.3M_{sun} WDs, objects that form from binary evolution....

The Serpens Molecular Cloud is one of the most active star-forming regions within 500pc, with over 1000 young stellar objects (YSOs) at different evolutionary stages. The ages...

We present optical spectroscopy observations of 145 high-mass pre-main-sequence candidates from the catalog of Vioque et al. (2020, PhD thesis University of Leeds) From these,...

We present results from high-resolution (R~40000) spectroscopic observations of over 200 metal-poor stars, mostly selected from the RAVE survey, using the Southern African Large...

Accretion plays an important role in protoplanetary disk evolution, and it is thought that the accretion mechanism changes between low- and high-mass stars. Here we characterize...

The kinematics and dynamics of stellar and substellar populations within young, still-forming clusters provide valuable information for constraining theories of formation...

Magnetic fields and mass accretion processes create dark and bright spots on the surface of young stars. These spots manifest as surface thermal inhomogeneities, which alter the...

We analyze space-based time-series photometry of Sun-like stars, mostly in the Pleiades, but also field stars and the Sun itself. We focus on timescales between roughly 1hr and...

The projected stellar rotational velocity (vsini) is critical for our understanding of processes related to the evolution of angular momentum in pre-main-sequence stars. We...