1,106 datasets found

The lack of knowledge of photospheric parameters and the level of chromospheric activity in young low-mass pre-main sequence stars introduces uncertainties when measuring mass...

Be stars are fast rotating early-type emission line stars. It is generally assumed that observed emission is generated in a rotating disk- like envelope, as supported by the...

Interstellar (IS) absorption lines or diffuse bands are usually extracted from early-type star spectra because they are characterized by smooth continua. However, this...

We perform a detailed elemental abundance analysis of dwarf stars in the Galactic bulge, based on high-resolution spectra that were obtained while the stars were optically...

The near-infrared (NIR) wavelength range offers some unique spectral features, and it is less prone to the extinction than the optical one. Recently, the first flux calibrated...

We present high-quality, medium-resolution X-shooter/VLT spectra in the range 300-2500nm for a sample of 12 very low mass stars in the {sigma} Orionis cluster. The sample...

We present a study of the column density distribution and cosmological mass density of neutral gas from a survey of Damped Lyman-alpha systems in the Sloan Digital Sky Survey...

Most observational studies conducted so far point toward brown dwarfs sharing a similar formation mechanism as the one that is accepted for low-mass stars. However, larger...

A significantly higher incidence of strong (rest equivalent width Wr>1{AA}) intervening MgII absorption is observed along gamma-ray burst (GRB) sight-lines relative to those...

In this work we analyze the spectroscopic properties of a large number of HII regions, ~2600, located in 38 galaxies. The sample of galaxies has been assembled from the face-on...

We present 6.5-m MMT and 3.5m APO spectrophotometry of 69 HII regions in 42 low-metallicity emission-line galaxies, selected from the data release 7 of the Sloan Digital Sky...

The main paper on the hypergiant HR8752 evolving through the void combines observational data from various sources: new spectral data, new and already published (B-V), V data....

We present H{alpha}3 (acronym for H{alpha}-{alpha}{alpha}), an H{alpha} narrow-band imaging survey of ~400 galaxies selected from the HI Arecibo Legacy Fast ALFA Survey...

Lithium abundances in open clusters are a very effective probe of mixing processes, and their study can help to understand the large depletion of lithium in the Sun. Due to its...

The planet-star interaction is manifested in many ways. It has been found that a close-in exoplanet causes small but measurable variability in the cores of a few lines in the...

Well determined radial velocities and abundances are essential for analyzing the properties of the Globular Cluster system of the Milky Way. However more than 50% of these...

We present the global properties (redshift, SED-based stellar mass and star formation rate, [OII]3727 flux and equivalent width) of the MASSIV sample. It contains 84...

We present positions and velocities for 796 planetary nebulae (PNe) in the Fornax Brightest Cluster Galaxy NGC 1316 (Fornax A). The planetary nebulae and existing kinematics are...

The ages of individual Red Giant Branch stars can range from 1Gyr old to the age of the Universe, and it is believed that the abundances of most chemical elements in their...

We have studied age dependent features in optical and near-infrared spectra of candidate members to the cluster (such as alkali lines and accretion associated indicators). In...