Related papers: Three newly discovered globular clusters in NGC 68…
Accurate photometry with HST/ACS shows that the main sequence of the globular cluster NGC 2808 splits into three separate branches. The three MS branches may be associated with complexities of the cluster's horizontal branch and of its…
We present new imaging measurements of 27 individual globular clusters in the halo of the nearby elliptical galaxy NGC 5128, obtained with the Hubble Space Telescope STIS and WFPC2 cameras. Combining these with similar data for selected…
We report the discovery of 4 strong gravitational lensing systems by visual inspections of the Sloan Digital Sky Survey images of galaxy clusters in Data Release 6 (SDSS DR6). Two of the four systems show Einstein rings while the others…
We present the unexpected discovery of four ultra diffuse galaxies (UDGs) in a group environment. We recently identified seven extremely low surface brightness galaxies in the vicinity of the spiral galaxy M101, using data from the…
We present deep Hubble Space Telescope imaging of five faint dwarf galaxies associated with the nearby spiral NGC 253 (D$\approx$3.5 Mpc). Three of these are newly discovered ultra-faint dwarf galaxies, while all five were found in the…
We study the properties of the globular cluster system of the ``old'' merger NGC 5018. We detect a relatively poor globular cluster system, that can be divided into at least two populations based on colors: a small population of blue…
Many strong gravitational lenses lie in complex environments, such as poor groups of galaxies, that significantly bias conclusions from lens analyses. We are undertaking a photometric survey of all known galaxy-mass strong lenses to…
We present new number density and surface brightness profiles for the globular cluster M92 (NGC 6341). These profiles are calculated from optical images collected with the CCD mosaic camera MegaCam at the Canada-France-Hawaii-Telescope and…
We study the globular clusters (GCs) in the spiral galaxy NGC~5907 well-known for its spectacular stellar stream -- to better understand its origin. Using wide-field Subaru/Suprime-Cam $gri$ images and deep Keck/DEIMOS multi-object…
We performed a search for new dwarf galaxies in a direction towards the southwestern part of the Local Void using the data on DESI Legacy Imaging Surveys. In a sky area of $\sim1000$ square degrees, we discovered 12 candidates to nearby…
Despite indications that classical cataclysmic variable (CV) stars are rare in globular clusters in general, and in the cluster NGC 6624 in particular, we have serendipitously discovered such a star ~6'' from the cluster center. A Hubble…
Globular clusters (GCs) are astronomical tapestries embroidered with an abundance of exotic stellar-type objects. Their high age promises a rich harvest of evolved stellar products, while the deep potential wells and high mass densities at…
We conduct a survey of low surface brightness (LSB) satellite galaxies around the Local Volume massive spirals using long exposures with small amateur telescopes. We identified 27 low and very low surface brightness objects around the…
We present new deep photometry of the globular cluster system (GCS) around NGC 6166, the central supergiant galaxy in Abell 2199. HST data from the ACS and WFC3 cameras in F475W, F814W are used to determine the spatial distribution of the…
Two ultra diffuse galaxies in the same group, NGC1052-DF2 and NGC1052-DF4, have been found to have little or no dark matter and to host unusually luminous globular cluster populations. Such low mass diffuse objects in a group environment…
We have conducted a photometric survey of the globular cluster NGC 6397 in a search for variable stars. We obtained ~11h of time-resolved photometric images with one ne European Southern Observatory-Very Large Telescope using the FOcal…
In this note we perform an analysis of the large set of microlensing events detected so far toward the Galactic center with the purpose of investigating whether some of the dark lenses are located in Galactic globular clusters. We find that…
We performed a high-sensitivity search for galaxy-scale magnetic fields by radio polarimetry at 10.45GHz and 4.85GHz with the Effelsberg 100m radio telescope, accompanied by Halpha imaging, for the two Local Group irregular galaxies IC10…
We present a detailed 3D kinematic analysis of the central regions ($R<30''$) of the low-mass and dynamically evolved galactic globular cluster NGC 6362. The study is based on data obtained with ESO-VLT/MUSE used in combination with the…
We have measured the absolute proper motions of globular clusters NGC 2808, 3201, 4372, 4833, 5927 and 5986. The proper motions are on the Hipparcos system and they are the first determinations ever made for these low Galactic latitude…