Related papers: New R CrB-Type Star HadV98
We report results of follow-up multicolor photometry of the optical variable source that is a probable remnant of the gamma-ray burst GRB970508 discovered by the BeppoSAX satellite (IAUC 6649). Observations were carried out in…
This project is a massive near-infrared (NIR) search for variable stars in highly reddened and obscured open cluster (OC) fields projected on regions of the Galactic bulge and disk. The search is performed using photometric NIR data in the…
Previous studies of the low surface brightness host of the blue compact galaxy (BCG) Haro 11 have suggested an abnormally red color of V-K=4.2+-0.8 for the host galaxy. This color is inconsistent with any normal stellar population over a…
We started a new project which aims to find compact hot subdwarf binaries at low Galactic latitudes. Targets are selected from several photometric surveys and a spectroscopic follow-up campaign to find radial velocity variations on…
Variability in Young Stellar Objects (YSOs) is one of their primary characteristics. Long-term, multi-filter, high-cadence monitoring of large YSO samples is the key to understand the partly unusual light-curves that many of these objects…
We report the discovery and multicolor (VRIW) photometry of a rare explosive star MASTER OT J004207.99+405501.1 - a luminous red nova - in the Andromeda galaxy M31N2015-01a. We use our original light curve acquired with identical MASTER…
Context. The development of refined instruments and techniques for a detailed analysis of the radial velocities (RVs) of stars other than the Sun allows the presence of planetary signals of amplitude below 1 ms$^{-1}$ to be investigated.…
HD 220392 (HR 8895), the brightest member of the visual double star CCDM 23239-5349, is a new short-period variable bright star, probably of the Delta Scuti type. The period analysis performed on the complete set of definitive Geneva…
It has been argued in the literature that the star HV~2112 in the Small Magellanic Cloud is the first known example of a T\.ZO, a Red Supergiant with a degenerate neutron core. This claim is based on the star having a high luminosity ($\log…
CCD photometry of the type Ia SN 2001V occured in the edge-on spiral galaxy NGC 3987 is presented. The observations made through Johnson-Cousins BVRI filters were collected from Feb. 24 (t = -8 days, with respect to B-maximum), up to May 5…
KIC8264293 is a fast rotating B-type pulsator observed by Kepler satellite. Its photometric variability is mainly due to pulsations in high-order g modes. Besides, we detected a weak H$\alpha$ emission. Thus, the second source of…
We continue the search for luminous blue variables (LBVs) in Local Volume galaxies in order to study their fundamental parameters. In this paper, we report the discovery of two new LBVs in the dwarf irregular galaxy NGC 1156. Both stars…
In this Letter, we report the results of spectroscopic and photometric monitoring of the candidate luminous blue variable (LBV) WS1, which was discovered in 2011 through the detection of a mid-infrared circular shell and follow-up optical…
(Abridged) We present CCD BVI photometry of 85 variable stars from the field of the globular cluster NGC 6934. The photometry was obtained with the image subtraction package ISIS. 35 variables are new identifications: 24 RRab stars, 5 RRc…
We present the first results of a time-resolved CCD photometric and time-series analysis of NSV 13601, a variable star of Pegasus constellation. The 14" SCT of Maharaja Krishnakumarsinhji Bhavnagar University(MKBU) was used for…
This study's objective was to exploit infrared VVV (VISTA Variables in the Via Lactea) photometry for high latitude RRab stars to establish an accurate Galactic Centre distance. RRab candidates were discovered and reaffirmed ($n=4194$) by…
We present the results from $VI$ CCD time-series photometry of the globular cluster M13 (NGC 6205). From the Fourier decomposition of the light curves of RRab and RRc stars we found an average metallicity of [Fe/H]zw = -1.58 $\pm$ 0.09. The…
Using the Southeastern Association for Research in Astronomy 0.6 meter telescope located at Cerro Tololo, we searched for variable stars in the southern globular cluster NGC 6584. We obtained images during 8 nights between 28 May and 6 July…
A radial velocity (RV) survey to detect central stars in binary systems was carried out between 2002 and 2004. De Marco et al. (2004) reported that 10 out of 11 monitored stars exhibited strong RV variability, but periods were not detected.…
GZ Cnc was discovered as a variable star by Takamizawa (Tmz V34), which turned out to a cataclysmic variable (CV). Past studies have shown that this object is a good candidate for a rarely outbursting, long-period dwarf nova. Only three…