Related papers: A Second Luminous Blue Variable in the Quintuplet …
New B, V, I photometry was obtained for a sample of 152 variables (125 RR Lyrae's, 4 anomalous Cepheids, 11 classical Cepheids, 11 eclipsing binaries and a delta Scuti star) in two regions near the bar of the Large Magellanic Cloud (LMC).…
We present spectroscopic and photometric observations of the emission-line star MWC 930 (V446 Sct) during its long-term optical brightening in 2006--2013. Based on our earlier data we suggested that the object has features found in Luminous…
There is now considerable evidence that horizontal branch (HB) stars hotter than about 11,500 K experience an enormous enhancement of their photospheric iron abundance due to radiative levitation. In globular clusters, the photospheric iron…
We observed seven central stars of planetary nebulae (CSPN) in the Large Magellanic Cloud (LMC) with the Far Ultraviolet Spectroscopic Explorer (FUSE), and performed a model-based analysis of these spectra in conjunction with Hubble Space…
We present new photometric and spectroscopic observations of an unusual luminous blue variable (LBV) in NGC 3432, covering three major outbursts in October 2008, April 2009 and November 2009. Previously, this star experienced an outburst…
The Quintuplet cluster, located in the Galactic centre, is one of the few young massive clusters in the Milky Way. It allows us to study dozens of massive, post main sequence stars individually, providing unique insights into the properties…
In a previous paper, we assembled a collection of medium-resolution spectra of 35 carbon stars, covering optical and near-infrared wavelengths from 400 to 2400 nm. The sample includes stars from the Milky Way and the Magellanic Clouds, with…
We study Luminous Blue Variable (LBV) candidate J004341.84+411112.0 in the Andromeda galaxy. We present optical spectra of the object obtained with the 6-m telescope of SAO RAS. The candidate shows typical LBV features in its spectra: broad…
In the current paper, we present a study of the spatial distribution of luminous blue variables (LBVs) and various LBV candidates (cLBVs) with respect to OB associations in the M33 galaxy. The identification of blue star groups was based on…
We report optical photometric and spectroscopic observations of the M33 star B416, establishing it as the fifth identified LBV in that galaxy. The B magnitude of the star varies with a period of 8.26 day and an amplitude of 0.03 magnitude.…
We report on new WFPC2 observations of the globular cluster NGC 288, focusing our attention on peculiar stars. A very pronounced binary sequence, paralleling the ordinary Main Sequence (MS) is clearly observed in the Color Magnitude Diagram…
MN112 is the Galactic luminous blue variable (LBV) candidate with circumstellar nebula. P Cygni is the first discovered LBV, which was recorded during major eruptions in the 17th century. The stars have similar spectra with strong emission…
Luminous Blue Variables (LBVs) are massive stars that are likely to be a transitionary phase between O stars and hydrogen-free classical Wolf-Rayet stars. The variability of these stars has been an area of study for both professional and…
We present the detection of a variable star with an $18.05$ minute period in far-ultraviolet (FUV) images of the globular cluster NGC 1851 taken with the Hubble Space Telescope (HST). A candidate optical counterpart lies on the red…
Atmospheric parameters (effective temperature, surface gravity) and radial velocities are derived for 12 candidate blue horizontal branch (HB) stars in the globular clusters 47 Tuc and NGC 362, which so far have been known to contain…
Three very massive clusters are known to reside in the Galactic Center region, the Arches cluster, the Quintuplet cluster and the Central parsec cluster. We obtained spectroscopic observations of the Quintuplet cluster with the Integral…
We have used deep I-band (F814W) images from the HST archive to study the globular cluster systems around the brightest cluster galaxies (BCGs) in Abell 262, 3560, 3565 and 3742. Three of these BCGs have inner dust lanes and peculiar…
We present a picture of the very unusual blue straggler S1082 in the old open cluster M67 whose light is the sum of a close binary (P = 1.0677978 d) and another cluster member. We provide a complete V-band light curve for the system, and…
We present the results of a search for variable stars in the faint sparse globular cluster E3. We have found two variable stars: an SX Phe variable (V1) and a W UMa eclipsing binary (V2). We have applied period-luminosity and…
Three fields covering the central part of the globular cluster Omega Cen were surveyed in a search for variable stars. We present V-band light curves for 22 periodic variables: 9 SX~Phe stars, 7 contact binaries, 5 detached or semi-detached…