Related papers: Early-type objects in NGC6611 and Eagle Nebula
H$\alpha$ emission is a clear indicator of circumstellar activity in Be stars, historically employed to assess the classical Be star (CBe) population in young open clusters (YOCs). The YOC NGC330 in the Small Magellanic Cloud exhibits a…
We have carried out a study of the early type stars in nearby OB associations spanning an age range of $\sim$ 3 to 16 Myr, with the aim of determining the fraction of stars which belong to the Herbig Ae/Be class. We studied the B, A, and F…
Galactic field Be stars were studied by taking into account the effects induced by the fast rotation on their fundamental parameters. Fractional ages $\tau/\tau\_{\rm MS}$ ($\tau\_{\rm MS}$ = time spent in the MS) against stellar mass…
We present FEROS high-resolution (R~45000) optical spectroscopy of 34 Herbig Ae/Be star candidates with previously unknown or poorly constrained spectral types. Within the sample, 16 sources are positionally coincident with nearby (d<250…
We derive a catalog of early-type emission-line stars including 30,048 spectra of 25,886 stars from LAMOST DR7, in which 3,922 have Simbad records. The sample is obtained using K-Nearest Neighbor and Random Forest methods and visually…
We present a spectroscopic analysis of the GIRAFFE and UVES data collected by the Gaia-ESO survey for the young open cluster NGC 3293. Archive spectra from the same instruments obtained in the framework of the `VLT-FLAMES survey of massive…
The origin of initial rotation rates of stars, and how a star's surface rotational velocity changes during the evolution, either by internal angular momentum transport or due to interactions with a binary companion, remain open questions in…
We explore the hypothesis that B type emission-line stars (Be stars) have their origin in mass-transfer binaries by measuring the fraction of runaway Be stars. We assemble the largest-to-date catalogue of 632 Be stars with 6D kinematics,…
At low metallicity, B-type stars show lower loss of mass and, therefore, angular momentum so that it is expected that there are more Be stars in the Magellanic Clouds than in the Milky Way. However, till now, searches for Be stars were only…
We present a photometric and spectroscopic study of the young open cluster NGC 7419, which is know to host a large number of classical Be stars for reasons not well understood. Based on CCD photometric observations of 327 stars in UBV…
The Gaia-ESO Survey (GES) is obtaining high quality spectra of $\sim$10$^{5}$ stars in our Galaxy, providing an homogeneous and unique overview of all the main components of the Milky Way, its formation history and the evolution of young,…
In the group of B stars with spectroscopic peculiarities, we can find the Be and the B[e] stars. The Be stars are early-type rapid rotators that present, as their principal characteristic, emission lines of hydrogen and singly ionized…
According to recent theoretical studies, the progenitors of Long Gamma Ray Bursts should be very fast rotating stars, massive enough but not so for collapsing into a black hole. In addition, recent observations seem to show that stars of…
A list of 50 optically observable O stars that are likely on or very near the ZAMS is presented. They have been selected on the basis of five distinct criteria, although some of them exhibit more than one. Three of the criteria are…
We present an analysis of high-resolution optical spectra recorded for 30 stars of the split extended main-sequence turnoff (eMSTO) of the young ($\sim$ 40 Myr) Small Magellanic Cloud (SMC) globular cluster NGC 330. Spectra were obtained…
We present a spectroscopic study of 150 Classical Be stars in 39 open clusters using medium resolution spectra in the wavelength range 3800 - 9000 \AA. One-third of the sample (48 stars in 18 clusters) has been studied for the first time.…
We report on the study of the population of B and Be stars in SMC young clusters, performed with the Wide Field Imager in slitless spectroscopic mode at ESO/T2.2m with a filter centered at Halpha. First, we explain the reduction methods we…
We report the analysis of the rotational properties of our sample of Herbig Ae/Be (HAeBe) and related stars for which we have obtained high-resolution spectropolarimetric observations. Using the projected rotational velocities measured at…
We present integral field unit (IFU) spectroscopy and self-consistent photoionisation modelling for a sample of four southern Galactic planetary nebulae (PNe) with supposed weak emission-line (WEL) central stars. The Wide Field Spectrograph…
The stellar populations of galaxies hold vital clues to their formation histories. In this paper we present results based on modeling stacked spectra of early-type galaxies drawn from the Sloan Digital Sky Survey (SDSS) as a function of…