Related papers: BSS populations from the WFPC2 UV Survey

Nearby dwarf galaxies provide a unique laboratory in which to test stellar population models below $Z_\odot/2$. Such tests are particularly important for interpreting the surprising high-ionization UV line emission detected at $z>6$ in…

We have searched for visual binaries with projected separations in the range 200-3000 AU (0.1"-1.5") among a sample of 96 stars in the massive young NGC 6611 cluster, 60 of them being subsequently identified as high probability cluster…

We present the results of an all-sky survey made with the Fine Guidance Sensor on Hubble Space Telescope to search for angularly resolved binary systems among the massive stars. The sample of 224 stars is comprised mainly of Galactic O- and…

The fraction of binary stars is an important ingredient to interpret globular cluster dynamical evolution and their stellar population. We investigate the properties of main-sequence binaries measured in a uniform photometric sample of 59…

A majority of massive stars are part of binary systems, a large fraction of which will inevitably interact during their lives. Binary-interaction products (BiPs), i.e. stars affected by such interaction, are expected to be commonly present…

We report on a data-driven spectral model that we have developed for the identification of double-lined spectroscopic binary stars (SB2s) in the LAMOST low-resolution survey (R$\sim$1800). Employing simultaneous fitting with both…

Simple stellar population (SSP) synthesis models are useful tools for studying the nature of unresolved star clusters in external galaxies. However, the plethora of currently available SSP models gives rise to significant and poorly…

We have used the Ultraviolet Imaging Telescope to obtain deep far-UV (1620 Angstrom), 40' diameter images of the prototypical metal-rich globular cluster 47 Tucanae. We find a population of about 20 hot (Teff > 9000 K) objects near or above…

In the present work we analyzed seven globular clusters selected from their location in the Galactic bulge and with metallicity values in the range $-1.30\lesssim\rm{[Fe/H]}\lesssim-0.50$. The aim of this work is first to derive cluster…

The aim of this work is to investigate the characteristics of the young stellar population in the spiral galaxy NGC 247. In particular, we focused our attention in its hierarchical clustering distributions and the properties of the smallest…

We have used WFPC2 to construct B, V color-magnitude diagrams of four metal-rich globular clusters, NGC 104 (47 Tuc), NGC 5927, NGC 6388, and NGC 6441. All four clusters have well populated red horizontal branches (RHB), as expected for…

We present the study of four FUV stars in the field of open cluster NGC 2420 using the Ultra Violet Imaging Telescope (UVIT) mounted on AstroSat. The three stars 525, 527, and 560 are members, while star 646 is a non-member of the cluster.…

In this paper, we describe a new method to select globular cluster (GC) candidates, including galaxy subtraction with unsharp masking, template fitting techniques and the inclusion of Gaia's proper motions. We report the use of the 12-band…

We have performed photometric analysis of four Galactic globular clusters (GGCs): NGC 4147, NGC 4590, NGC 5053 and NGC 7492 using far-UV and near-UV filters of the Ultraviolet Imaging Telescope (UVIT) on-board AstroSat. With the help of…

In this paper we present preliminary results from our HST project aimed at exploring the connection between the stellar dynamics and stellar evolution in the cores of high-density globular clusters. We illustrate the discovery of horizontal…

We report results from Hubble Space Telescope WFPC2 imaging of the field of the luminous, bursting X-ray source in the globular cluster NGC 6441. Although the X-ray position is known to a precision of a few arcseconds, this source is only…

We have used deep V-band and JHKs-band observations to investigate variability and stellar populations near the Galactic plane in Centaurus, and compared the observations with the Galactic model of Besancon. By applying image subtraction…

We present the study of dynamical status of the globular cluster NGC 1851. A combination of multiwavelength space and ground-based data sets are used for the present analysis. In order to select the genuine cluster members, we used the…

The physical properties of star cluster populations offer valuable insights into their birth, evolution, and disruption. However, individual stars in clusters beyond the nearest neighbours of the Milky Way are unresolved, forcing analyses…

We use Cycle 21 Hubble Space Telescope (HST) observations and HST archival ACS Treasury observations of Galactic Globular Clusters to find and characterize two stellar populations in NGC 5024 (M53), NGC 5272 (M3), and NGC 6352. For these…