Related papers: Discovery of 79 $\delta$ Scuti Stars in NGC 3532 S…
We have made extensive observations of 35 distant slow (non-recycled) pulsars discovered in the ongoing Arecibo PALFA pulsar survey. Timing observations of these pulsars over several years at Arecibo Observatory and Jodrell Bank Observatory…
New photometric observations of seven intermediate mass pre-main sequence delta Scuti candidates are presented. The periods and pulsation modes are derived for two of these stars, namely HD 35929 and V351 Ori. The comparison between…
The large separation in the low radial order regime is considered as a highly valuable observable to derive mean densities of $\delta$ Scuti stars, due to its independence with rotation. Up to now, theoretical studies of this…
(ABBREVIATED:) The large majority of extragalactic star cluster studies done to date have essentially used two or three-passband aperture photometry, combined with theoretical stellar population synthesis models, to obtain age, mass and…
The [Sr/Ba] and [Y/Ba] scatter observed in some galactic halo stars that are very metal-poor stars and in a few individual stars of the oldest known Milky Way globular cluster NGC 6522,have been interpreted as evidence of early enrichment…
Scaling relations that link asteroseismic quantities to global stellar properties are important for gaining understanding of the intricate physics that underpins stellar pulsation. The common notion that all stars in an open cluster have…
Shells in Elliptical Galaxies are faint, sharp-edged features, believed to provide evidence of a recent ($\sim 0.5 - 2 \times 10^9$ years ago) merger event. We analyse the Globular Cluster (GC) systems of six shell elliptical galaxies, to…
Period changes of Delta Scuti stars have been collected or redetermined from the available observations and are compared with values computed from evolutionary models with and without convective core overshooting. For the radial pulsators…
We use the ages, masses and metallicities of the rich young star cluster systems in the nearby starburst galaxies NGC 3310 and NGC 6745 to derive their cluster formation histories and subsequent evolution. We further expand our analysis of…
We present the results of time-series photometric analysis of 15106 A-K type stars observed by the Kepler space mission. We identified 513 new rotational variables and measured their starspot rotation periods as a function of spectral type…
Context: Rapid rotation is a common feature of early-type stars but which remains a challenge for the models. The understanding of its effect on stellar evolution is however imperative to interpret the observed properties of numerous stars.…
We present an analysis on the behaviour of the Galactic bulge and the Large Magellanic Cloud (LMC) $\delta$ Scuti stars in terms of period-colour and amplitude-colour (PCAC) relations at maximum, mean and minimum light. The publicly…
Recent dramatic improvements in the modeling of abundance evolution due to diffusion in A stars have been achieved with the help of monochromatic opacity tables from the OPAL group. An important result in the context of stellar pulsations…
Multiple generations of stars are routinely encountered in globular clusters but no convincing evidence has been found in Galactic open clusters to date. In this paper we use new photometric and spectroscopic data to search for multiple…
Among the $\sim 4000$ known pulsars in our Galaxy, $\lesssim 10\%$ are found in globular clusters, but none has been confirmed in any open clusters yet, although they outnumber globular clusters by about 20 times. In this work, we make use…
CCD observations of stars in the young cluster IC 348 were obtained from 2004 August to 2005 January with a 0.45 m ROTSEIIId robotic reflecting telescope at the Turkish National Observatory site, Bakirlitepe, Turkey. The timing analysis of…
During the last two years we have received long time-series photometric observations of bright (V mag < 8) main-sequence A- and B-type stars observed by the NASA TESS spacecraft and the Austria-Poland-Canada BRITE satellites. Using TESS…
Context: Open clusters' dynamical evolution is driven by stellar evolution, internal dynamics and external forces, which according to dynamical simulations, will evaporate them in a timescale of about 1 Ga. However, about 10\% of the known…
The mysterious high galactic latitude cometary globule CG12 has been observed with the ACIS detector on board the Chandra X-ray Observatory. We detect 128 X-ray sources; half are likely young stars formed within the globule's head. This new…
V-band time-series CCD photometric observations of the intermediate-age open cluster M11 were performed to search for variable stars. Using these time-series data, we carefully examined light variations of all stars in the observing field.…