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Related papers: Digging deeper into the dense Galactic globular cl…

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The Fermi Large Area Telescope (LAT) has recently detected a population of globular clusters (GCs) in high-energy (HE) gamma-rays. Their spectral properties and energetics are consistent with cumulative emission from a population of…

High Energy Astrophysical Phenomena · Physics 2011-11-08 C. Venter , O. C. de Jager , A. Kopp , I. Büsching

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…

Solar and Stellar Astrophysics · Physics 2012-07-17 Joseph M. Toddy , Elliott W. Johnson , Andrew N. Darragh , Brian W. Murphy

Globular clusters host large populations of millisecond pulsars (MSPs) due to their high gravitational encounter rates, producing many binary systems and thus MSPs via the recycling process. Seven pulsars with spin periods ranging from 3 ms…

High Energy Astrophysical Phenomena · Physics 2024-12-17 Justine Singleton , Megan DeCesar , Shi Dai , Deven Bhakta , Scott Ransom , Jay Strader , Laura Chomiuk , James Miller-Jones

We present results of new photometry for the globular star cluster NGC 2155 in the Large Magellanic Cloud (LMC). Our I- and V-band observations were obtained with the 6.5-meter Magellan 1 Baade Telescope at Las Campanas Observatory…

Solar and Stellar Astrophysics · Physics 2011-06-07 M. Otulakowska , A. Olech , W. Pych , A. A. Pamyatnykh , T. Zdravkov , S. M. Rucinski

We present the results of a massive variability search based on a photometric survey of a six square degree region along the Galactic plane at ($l = 305^\circ$, $b = -0.8^\circ$) and ($l = 330^\circ$, $b = -2.5^\circ$). This survey was…

We present VI-band photometry for stars in the metal-rich globular cluster NGC 6496. Our time-series data were cadenced to search for long period variables (LPVs) over a span of nearly two years, and our variability search yielded the…

We report on photometry results of the equatorial globular clusters (GCs) M10 and M12. These two clusters are part of our sample of GCs which we are probing for the existence of photometrically varying eclipsing binary stars. During the…

We present a sample of 171 candidate groups and clusters of galaxies at intermediate redshift over an area of ~550 square degrees at the South Galactic Pole selected by using optically identified radio sources from the NRAO VLA Sky Survey…

Astrophysics · Physics 2009-11-07 A. Zanichelli , R. Scaramella , G. Vettolani , M. Vigotti , S. Bardelli , G. Zamorani

We report CCD V and I time series photometry of the globular cluster NGC 5024 (M53). The technique of difference image analysis has been used which enables photometric precisions better than 10 mmag for stars brighter than V 18.5mag even in…

Solar and Stellar Astrophysics · Physics 2015-05-28 A. Arellano Ferro , R. Figuera Jaimes , Sunetra Giridhar , D. M. Bramich , J. V. Hernandez Santisteban , K. Kuppuswamy

We present high precision CCD photometry of 1791 objects in 20 open clusters with an age from 10 Myr to 1 Gyr. These observations were performed within the Delta a photometric system which is primarily used to detect chemically peculiar…

Astrophysics · Physics 2009-11-10 E. Paunzen , K. Zwintz , H. M. Maitzen , O. I. Pintado , M. Rode-Paunzen

Context: Difference imaging has proven to be a powerful technique for detecting and monitoring the variability of unresolved stellar sources in M 31. Using this technique in surveys of galaxies outside the Local Group could have many…

Astrophysics · Physics 2008-03-11 Jelte T. A. de Jong , Konrad H. Kuijken , Philippe Heraudeau

The peripheral regions of globular clusters (GCs) are extremely challenging to study due to their low surface brightness nature and the dominance of Milky Way contaminant populations along their sightlines. We have developed a probabilistic…

Astrophysics of Galaxies · Physics 2021-08-18 Pete B. Kuzma , Annette M. N. Ferguson , Jorge Peñarrubia

We present the first CCD photometric observations of the northern open cluster NGC 2126. Data were taken on eight nights in February and December 2002 with a total time span of ~57 hours. Almost 1000 individual V-band frames were examined…

Astrophysics · Physics 2009-03-09 A. Gaspar , L. L. Kiss , T. R. Bedding , A. Derekas , S. Kaspi , Cs. Kiss , K. Sarneczky , Gy. M. Szabo , M. Varadi

We report on the discovery of three new millisecond pulsars (namely J1748-2446aj, J1748-2446ak and J1748-2446al) in the inner regions of the dense stellar system Terzan 5. These pulsars have been discovered thanks to a method, alternative…

High Energy Astrophysical Phenomena · Physics 2018-03-28 M. Cadelano , S. M. Ransom , P. C. C. Freire , F. R. Ferraro , J. W. T. Hessels , B. Lanzoni , C. Pallanca , I. H. Stairs

We have used archival Hubble Space Telescope observations obtained with the Advanced Camera for Surveys to study the H{\alpha} emission properties of main sequence stars in the globular cluster 47 Tucanae. Using a combination of multi-band…

Solar and Stellar Astrophysics · Physics 2015-06-17 G. Beccari , G. De Marchi , N. Panagia , L. Pasquini

We report on an ambitious multi-site campaign aimed at detecting stellar variability, particularly solar-like oscillations, in the red giant stars in the open cluster M67 (NGC 2682). During the six-week observing run, which comprised 164…

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

The Chinese Small Telescope ARray (CSTAR) carried out high-cadence time-series observations of 27 square degrees centered on the South Celestial Pole during the Antarctic winter seasons of 2008, 2009 and 2010. Aperture photometry of the…

The luminosity distribution of Galactic radio pulsars is believed to be log-normal in form. Applying this functional form to populations of pulsars in globular clusters, we employ Bayesian methods to explore constraints on the mean and…

Solar and Stellar Astrophysics · Physics 2015-06-11 Jayanth Chennamangalam , D. R. Lorimer , Ilya Mandel , Manjari Bagchi

Deep B,V time-series photometry obtained with the ESO Very Large Telescope has been used to identify variable stars in the dwarf irregular galaxy NGC 6822. We surveyed a 6.8x6.8 arcmin area of the galaxy and detected a total number of 390…

Astrophysics · Physics 2009-11-10 L. Baldacci , L. Rizzi , G. Clementini , E. V. Held