Related papers: Discovery of lambda Boo stars in open clusters
Context. Open clusters (OCs) are groups of stars formed from the same cloud of gas and cosmic dust. They play an important role in studies of star formation and evolution and our understanding of galaxy structure and dynamics. Aims. The…
The very young open cluster NGC 6383 centered on the O-star binary HD 159176 is an interesting place for studying the impact of early-type stars with strong radiation fields and powerful winds on the formation processes of low-mass stars.…
The triple system HD158926 (lambda Sco) has been observed interferometrically with the Sydney University Stellar Interferometer and the elements of the wide orbit have been determined. These are significantly more accurate than the previous…
Historically, it has often been asserted that most stars form in compact clusters. In this scenario, present-day gravitationally-unbound OB associations are the result of the expansion of initially gravitationally-bound star clusters.…
Recent investigations have revealed a surprising lack of close binaries among extreme horizontal branch (EHB) stars in the globular cluster NGC6752, at variance with the analogous sdB field stars. Another puzzling result concerns the…
Rup147 is the closest old open cluster, with a distance of less than 300 pc and an age of about 2.5Gyr. It is therefore well suited for testing stellar evolution models and for obtaining precise and detailed chemical abundance information.…
Binary clusters account for more than 10 % of the cluster population in the Magellanic Clouds. Statistically fewer than 50 % of the found pairs are expected to be chance superpositions. We estimated the cluster encounter rate and suggest…
Investigating the chemical homogeneity of stars born from the same molecular cloud at virtually the same time is very important for our understanding of the chemical enrichment of the interstellar medium and with it the chemical evolution…
A search for duplicity of lambda Bootis stars has been made by using the speckle camera installed at the Telescopio Nazionale Galileo. The operation mode and the reduction procedure allow one to obtain not only the separation, but also the…
Open clusters are useful tools to investigate the structure and evolution of the Galactic disk. We have started a long-term project to obtain UBVI CCD Photometry of open clusters which were little studied before, using the Doyak 1.8 m…
Embedded clusters are formed in molecular clouds where massive stars can produce HII regions. The detailed embedded-open cluster evolutionary connection as well as the origin of associations are yet to be unveiled. There appears to be a…
We present a new catalogue of 578 OB cluster (OBC) candidates in the Andromeda galaxy (M31), identified using a MeanShift-based algorithm on HST's F275W-band imaging from the PHAT (Dalcanton et al. 2012) and PHAST (Chen et al. 2025) Hubble…
Context. Stellar physical properties of star clusters are poorly known. Aims. Our goals are to perform a spectrophotometric study of the B star population in open clusters to derive accurate stellar parameters, search for the presence of…
The abundance anomalies in lambda Boo stars are popularly explained by element-specific mass inflows at rates that are much greater than empirically-inferred bounds for interstellar accretion. Therefore, a lambda Boo star's thin outer…
Aims: To try and clarify whether there are stars in the neighbourhood of $\beta$ Lyrae which are physically connected to the famous prototype eclipsing binary. Methods: Scrutinize the astrometric and photometric data (from Hipparcos and…
The pre-main-sequence evolution of the chemically peculiar (CP) stars on the upper main sequence is still a vast mystery and not well understood. Our analysis of young associations and open clusters aims to find (very) young CP stars to try…
Split main-sequences (MSs) and extended main-sequence turn-offs (eMSTOs) have been observed in nearly all Magellanic Clouds clusters younger than 2 Gyr. More recently, Hubble Space Telescope (HST) ultraviolet photometry uncovered a puzzling…
This work communicates the discovery of a binary open cluster within the Galaxy. NGC 1605 presents an unusual morphology with a sparse stellar distribution and a double core in close angular proximity. The 2MASS and Gaia-EDR3 field-star…
The formation and evolution of young star clusters and OB associations is fundamental to our understanding of the star formation process, the conditions faced by young binary and planetary systems, and the formation of long-lived open and…
We present a study of the abundance of Be stars in open clusters as a function of the cluster age, using whenever possible ages determined through Stromgren uvby photometry. For the first time in studies of this kind we have considered…