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Related papers: Stellar Variability in the Globular Cluster Terzan…

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We have calculated the physical parameters of the RR Lyrae stars in the globular cluster NGC~4147 via the Fourier decomposition of their light curves, using new data and well-established semi-empirical calibrations and zero points. The mean…

Solar and Stellar Astrophysics · Physics 2018-03-15 A. Arellano Ferro , F. C. Rojas Galindo , S. Muneer , Sunetra Giridhar

We present the chemical abundance analysis of 33 red giant stars belonging to the complex stellar system Terzan 5. We confirm the discovery of two stellar populations (Ferraro et al. 2009, Nature, 462,483) with distinct iron abundances: a…

Astrophysics of Galaxies · Physics 2015-05-20 L. Origlia , R. M. Rich , F. R. Ferraro , B. Lanzoni , M. Bellazzini , E. Dalessandro , A. Mucciarelli , E. Valenti , G. Beccari

Containing the oldest stars in the Galaxy, globular clusters toward the bulge can be used to trace its dynamical and chemical evolution. In the bulge direction, there are ~50 clusters, but only about 20% have been subject of high-resolution…

Solar and Stellar Astrophysics · Physics 2015-06-23 E. Valenti , L. Origlia , A. Mucciarelli , R. M. Rich

We present the deepest and highest-resolution radio continuum imaging of the Galactic globular cluster Terzan 5, one of the most crowded locations in the radio sky. In these new 2$-$4 GHz Karl G. Jansky Very Large Array images, we detect 38…

High Energy Astrophysical Phenomena · Physics 2026-02-12 Ryan Urquhart , Jay Strader , Laura Chomiuk , Scott M. Ransom , Craig O. Heinke , Arash Bahramian , Thomas J. Maccarone

We report CCD $V$ and $I$ time-series photometry of the globular cluster NGC 6333 (M9). The technique of difference image analysis has been used, which enables photometric precision better than 0.05 mag for stars brighter than $V \sim 19.0$…

We present the results of a comprehensive search for stellar variability in the globular cluster 47 Tucanae. Using the Mount Stromlo 40-inch (1m) telescope at Siding Spring Observatory and a combined V+R filter, we have detected 100…

Astrophysics · Physics 2010-02-18 David T F Weldrake , Penny D Sackett , Terry J Bridges , Kenneth C Freeman

We report a result of our near-infrared repeated observations of Mira variables in the globular clusters NGC 6388 and 6441. These two clusters are known as peculiar clusters with blue horizontal branch stars and RR Lyr variables which are…

Astrophysics · Physics 2007-05-23 Noriyuki Matsunaga , the IRSF/SIRIUS team

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…

Solar and Stellar Astrophysics · Physics 2015-05-30 Yogesh C. Joshi , Santosh Joshi , Brijesh Kumar , Soumen Mondal , L. A. Balona

Observations show that globular clusters might be among the best places to find millisecond pulsars. However, the globular cluster Terzan 6 seems to be an exception without any pulsar discovered, although its high stellar encounter rate…

High Energy Astrophysical Phenomena · Physics 2024-10-03 Shi-Jie Gao , Yi-Xuan Shao , Pei Wang , Ping Zhou , Xiang-Dong Li , Lei Zhang , Joseph W. Kania , Duncan R. Lorimer , Di Li

Variable stars have been identified for the first time in Fornax 4, the globular cluster located near the center of the Fornax dwarf spheroidal galaxy. By applying the image subtraction technique to B,V time series photometry obtained with…

This work presents the first long-term photometric variability survey of the intermediate-age open cluster NGC 559. Time-series V band photometric observations on 40 nights taken over more than three years with three different telescopes…

Solar and Stellar Astrophysics · Physics 2020-09-30 Yogesh C. Joshi , Ancy Anna John , Jayanand Maurya , Alaxendra Panchal , Brijesh Kumar , Santosh Joshi

In this paper we revisit observational data concerning RR Lyrae stars in Galactic globular clusters, presenting frequency histograms of fundamentalized periods for the 32 clusters having more than 12 pulsators with well recognized period…

Astrophysics · Physics 2009-11-10 M. Castellani , F. Caputo , V. Castellani

Terzan 5 is the only Galactic globular cluster that has plausibly been detected at very-high energies by the High Energy Stereoscopic System. It has an unexpectedly asymmetric very-high-energy morphology that is offset from the cluster…

High Energy Astrophysical Phenomena · Physics 2019-07-31 Hambeleleni Ndiyavala , Christo Venter , Tyrel J. Johnson , Alice K. Harding , David A. Smith , Peter Eger , Andreas Kopp , Johan van Der walt

We present the analysis of 11 nights of V and I time-series observations of the globular cluster NGC 1904 (M 79). Using this we searched for variable stars in this cluster and attempted to refine the periods of known variables, making use…

Solar and Stellar Astrophysics · Physics 2015-06-11 N. Kains , D. M. Bramich , R. Figuera Jaimes , A. Arellano Ferro , S. Giridhar , K. Kuppuswamy

We have performed a photometric V, R, I CCD time-series analysis with a baseline of ~8 years of the outer-halo globular cluster NGC 7492 with the aim of searching for new variables and using these (and the previously known variables) to…

Solar and Stellar Astrophysics · Physics 2015-06-16 R. Figuera Jaimes , A. Arellano Ferro , D. M. Bramich , Sunetra Giridhar , K. Kuppuswamy

CCD observations for 10 (6 previously known and 4 newly discovered) of the 11 RR Lyrae variables in NGC 5897 have been analysed. The period-luminosity and period-amplitude plots indicate that the population of RR Lyrae variables in NGC 5897…

Astrophysics · Physics 2009-11-06 Christine M. Clement , Jason F. Rowe

We present an analysis of 745.6 ks of archival Chandra X-ray Observatory Advanced CCD Imaging Spectrometer data accumulated between 2000 and 2016 of the millisecond pulsar (MSP) population in the rich Galactic globular cluster Terzan 5.…

High Energy Astrophysical Phenomena · Physics 2021-05-19 Slavko Bogdanov , Arash Bahramian , Craig O. Heinke , Scott M. Ransom

This thesis work is focused on the study of millisecond pulsars in globular cluster by using multi-wavelength observations obtained with radio and optical telescopes. Radio observations have been used to search for and timing the pulsars.…

High Energy Astrophysical Phenomena · Physics 2019-01-15 M. Cadelano

We present B, V and I CCD light curves for 101 variable stars belonging to the globular cluster NGC2419, 60 of which are new discoveries, based on datasets obtained at the TNG, SUBARU and HST telescopes. The sample includes 75 RR Lyrae…

Solar and Stellar Astrophysics · Physics 2015-05-20 M. Di Criscienzo , C. Greco , V. Ripepi , G. Clementini , M. Dall' Ora , M. Marconi , I. Musella , L. Federici , L. Di Fabrizio

We present V-band CCD photometry of 65 RR Lyr variables from the globular cluster M5. We have estimated the basic physical parameters for 16 RRc stars and 26 RRab stars using a Fourier decomposition of the light curves of the variables. The…

Astrophysics · Physics 2007-05-23 J. Kaluzny , A. Olech , I. Thompson , W. Pych , W. Krzeminski , A. Schwarzenberg-Czerny