45 datasets found

Blue supergiants (BSGs) are key objects for understanding the evolution of massive stars. However, discrepancies between theoretical predictions and empirical observations have...

We recently found the globular cluster (GC) EXT8 in M31 to have an extremely low metallicity of [Fe/H]=-2.91+/-0.04 using high-resolution spectroscopy. Here we present a...

This work is part of the Gaia Data Processing and Analysis Consortium papers published with the Gaia Early Data Release 3 (EDR3). It is one of the demonstration papers aiming to...

Cygnus OB2 provides a unique insight into the high-mass stellar content in one of the largest groups of young massive stars in our Galaxy. Although several studies of its...

We aim to explore the variable photometric and stellar properties of four yellow hypergiants (YHGs), HR 8752, HR 5171A, rho Cas, and HD 179821, and their pulsations of hundreds...

We report a new star formation history for the Tucana dwarf spheroidal galaxy, obtained from a new look at a deep HST/ACS colour-magnitude diagram. We combined information from...

Protoplanetary disks are the birth environments of planetary systems. Therefore, the study of young, circumstellar environments is essential to understanding the processes...

The second Gaia data release (Gaia DR2) contains high-precision positions, parallaxes, and proper motions for 1.3 billion sources. The resulting Hertzsprung-Russel diagram...

Ruprecht 147 (NGC 6774) is the closest old open cluster, with a distance of less than 300pc and an age of about 2.5Gyr. It is therefore well suited for testing stellar evolution...

With the availability of parallaxes provided by the Tycho-Gaia Astrometric Solution, it is possible to construct the Hertzsprung-Russell diagram (HRD) of barium and related...

Stellar clusters in the Small Magellanic Cloud (SMC) are useful probes to study the chemical and dynamical evolution of this neighbouring dwarf galaxy, enabling inspection of a...

We analyze the non-standard mixing history of the solar twins HIP 55459, HIP 79672, HIP 56948, HIP 73815, and HIP 100963, to determine as precisely as possible their mass and...

We investigate the spatial distribution, the space velocities and age distribution of the pre-main sequence (PMS) stars belonging to Ophiuchus, Lupus and Chamaeleon star-forming...

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UBV observations of over 37,000 stars have been compiled from the literature to yield 165 color-magnitude diagrams. There is a list of bibliographic references for each cluster...

The tracks cover the mass interval from 0.6 to 120M_{sun}_, for 7 different metallicities The isochrones are derived from the evolutionary tracks listed in the item above.

The table provides improved numerical relations between effective temperatures of stars, their B-V colors, and their bolometric corrections (BC) for the purpose of comparing...

CCD photometry of the intermediate-age open cluster IC 4651 on the uvbyH{beta} system is presented and analyzed. By using a combination of the information from the...

Infrared JKs-band photometry of the Galactic globular clusters M15 and, for the first time, M56 is presented. We estimate the reddening [E(B-V) = 0.18 {=/-} 0.08 mag] and...

In this paper we present large grids of theoretical isochrones for the initial chemical compositions [Z=0.0004, Y=0.23], [Z=0.004, Y=0.24], [Z=0.008, Y=0.25], [Z=0.02, Y=0.28],...