Related papers: Variables in Globular Cluster NGC 5024
Multi-wavelength CCD photometry over 21 years has been used to produce deep color-magnitude diagrams together with light curves for the variables in the Galactic globular cluster NGC 5824. Twenty-one new cluster RR Lyrae stars are…
We conducted a variable star search on the metal-rich Galactic globular cluster NGC 6652 using archival Gemini-S/GMOS data. We report the discovery of nine new variable stars in the NGC 6652 field, of which we classify six as eclipsing…
We present the preliminary results of an image-subtraction analysis of the Galactic globular cluster M79 (NGC 1904), as well as a new investigation of the variable star population in NGC 1851. Both M79 and NGC 1851 have been previously…
We present a new, deep (V ~ 26) study of the Galactic globular cluster NGC 2419 based on B,V,I time-series CCD photometry over about 10 years and extending beyond the cluster published tidal radius. We have identified 101 variable stars of…
We identify 228 periodic variables in the region of young open cluster NGC 281 using time series photometry carried out from 1 m class ARIES telescopes, Nainital. The cluster membership of these identified variables is determined on the…
Searches for planetary transits carried out in open and globular clusters have yielded to date only a handful of weak, unconfirmed candidates. These results have been interpreted either as being insignificant, or as evidence that the…
We have observed the recently discovered rich star cluster GLIMPSE-C01 for 46 ks with the Chandra X-ray Observatory. Seventeen X-ray sources with luminosities greater than 0.6e31 ergs/s were discovered, one of which is likely a quiescent…
We report an analysis of new $V$ and $I$ CCD time-series photometry of the distant globular cluster NGC 6229. The principal aims were to explore the field of the cluster in search of new variables, and to Fourier decompose the RR Lyrae…
In this paper we present time series photometry of 104 variable stars in the cluster region NGC 1893. The association of the present variable candidates to the cluster NGC 1893 has been determined by using $(U-B)/(B-V)$ and $(J-H)/(H-K)$…
We present the results of a photometric and spectroscopic survey of the globular cluster system of NGC 5128 (Centaurus A), a galaxy whose proximity makes it an important target for early-type galaxy studies. We imaged three fields in UBVRI…
We report on the results of a long time photometric monitoring of the two metal poor Galactic globular clusters M22 and IC4499 searching for long period variables (LPVs) on the upper giant branch. We detected 22 new LPVs in the field of M22…
We present results of a variability search in the intermediate-age open cluster NGC 6866 from 29 nights over two observing seasons. We find 28 periodic variables, of which 19 are newly identified. The periods of these variables, which have…
We used the 50 cm Binocular Network (50BiN) telescope at Delingha Station (Qinghai Province) of Purple Mountain Observatory (Chinese Academy of Sciences) to obtain simultaneous $V$- and $R$-band observations of the old open cluster NGC 188.…
We have searched for optical identifications for 79 Chandra X-ray sources that lie within the half-mass radius of the nearby, core-collapsed globular cluster NGC 6397, using deep Hubble Space Telescope Advanced Camera for Surveys Wide Field…
Evidence is emerging that the luminous X-ray sources in the cores of globular clusters may often consist of, or perhaps even as a class be dominated by, ultracompact (P < 1 hr) binary stars. To the two such systems already known, in NGC…
We present the results of a pair of 100 ksec Chandra observations in the Small Magellanic Cloud to survey high mass X-ray binaries (HMXBs), stars and LMXBs/CVs down to Lx = 4.3 x 10^32 erg/s The two SMC Deep Fields are located in the most…
We present the results of our search for variable stars in the intermediate-age open cluster NGC 7789. We have found 45 variable stars: 35 eclipsing binaries, five pulsating variables and five miscellaneous variables. Most of the eclipsing…
This paper presents the first optical variability study of the Westerlund 1 super star cluster in search of massive eclipsing binary systems. A total of 129 new variable stars have been identified, including the discovery of 4 eclipsing…
In this work, we search the OGLE-IV outer Galactic bulge fields for short-period variable objects. The investigation focuses on unexplored timescales roughly below one hour in an area containing about 700 million stellar sources down to…
We investigate the X-ray and optical properties of a sample of X-ray bright sources from the Small Magellanic Cloud (SMC) Wing Survey. We have detected two new pulsars with pulse periods of 65.8 s (CXOU J010712.6-723533) and 700 s (CXOU…