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At low metallicity, B-type stars show lower loss of mass and, therefore, angular momentum so that it is expected that there are more Be stars in the Magellanic Clouds than in the Milky Way. However, till now, searches for Be stars were only…

Astrophysics · Physics 2009-11-13 Christophe Martayan , Dietrich Baade , Juan Fabregat

This paper checks on the roles of metallicity and evolutionary age in the appearance of the so-called Be phenomenon. Slitless CCD spectra were obtained covering the bulk of the Small Magellanic Cloud. For Halpha line emission twice as…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Christophe Martayan , Dietrich Baade , Juan Fabregat

We report on the study of the population of B and Be stars in SMC young clusters, performed with the Wide Field Imager in slitless spectroscopic mode at ESO/T2.2m with a filter centered at Halpha. First, we explain the reduction methods we…

We present an analysis of high-resolution optical spectra recorded for 30 stars of the split extended main-sequence turnoff (eMSTO) of the young ($\sim$ 40 Myr) Small Magellanic Cloud (SMC) globular cluster NGC 330. Spectra were obtained…

Solar and Stellar Astrophysics · Physics 2024-06-18 Paul I. Cristofari , Andrea K. Dupree , Antonino P. Milone , Matthew G. Walker , Mario Mateo , Aaron Dotter , John I. Bailey

Observations of hot stars belonging to the young cluster SMC-NGC330 and its surrounding region were obtained with the VLT-GIRAFFE facilities in MEDUSA mode. We investigated the B and Be star properties and proportions in this environment of…

We present new observations of 470 stars using the Fibre Large Array Multi-Element Spectrograph (FLAMES) instrument in fields centered on the clusters NGC 330 and NGC 346 in the Small Magellanic Cloud (SMC), and NGC 2004 and the N11 region…

Astrophysics · Physics 2007-05-23 C. J. Evans , D. J. Lennon , S. J. Smartt , C. Trundle

Thanks to observations at the ESO VLT with the GIRAFFE multifibers spectrograph, we have obtained spectra of 177 and 346 B-type stars in the Large and Small Magellanic Clouds respectively. We have discovered 25 and 90 new Be stars among the…

The number and the nature of emission line stars in the young open cluster NGC6611 is still the object of debates. Due to the presence of a strong and variable nebulosity in the cluster, the number of emission line stars is highly depending…

We present Be star candidates in the open cluster NGC\,663, identified by H$\alpha$ imaging photometry with the Palomar Transient Factory Survey, as a pilot program to investigate how the Be star phenomena, the emission spectra, extended…

Astrophysics of Galaxies · Physics 2015-06-23 P. C. Yu , C. C. Lin , W. P. Chen , C. D. Lee , W. H. Ip , C. C. Ngeow , Russ Laher , Jason Surace , Shrinivas R. Kulkarni

We present a catalogue of new spectral types for hot, luminous stars in the Small Magellanic Cloud. The catalogue contains 4161 objects, giving an order of magnitude increase in the number of SMC stars with published spectroscopic…

Astrophysics · Physics 2014-10-13 C. J. Evans , I. D. Howarth , M. J. Irwin , A. W. Burnley , T. J. Harries

We present a large sample (20 in total) of optical spectra of Small Magellanic Cloud (SMC) High-Mass X-ray Binaries obtained with the 2dF spectrograph at the Anglo-Australian Telescope. All of these sources are found to be Be/X-ray binaries…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Vallia Antoniou , Despina Hatzidimitriou , Andreas Zezas , Pablo Reig

We present a deep survey of Halpha emission-line stars in the M42 region using wide-field objective prism films. A total of 1699 Halpha emission-line stars were identified, of which 1025 were previously unknown, within an area of 5.5 x 5.5…

Solar and Stellar Astrophysics · Physics 2014-11-25 Bertil Pettersson , Tina Armond , Bo Reipurth

H$\alpha$ emission is a clear indicator of circumstellar activity in Be stars, historically employed to assess the classical Be star (CBe) population in young open clusters (YOCs). The YOC NGC330 in the Small Magellanic Cloud exhibits a…

Astrophysics of Galaxies · Physics 2024-05-22 Felipe Navarete , Pedro Ticiani dos Santos , Alex Cavaliéri Carciofi , André Luiz Figueiredo

Star clusters are privileged laboratories for studying the evolution of massive stars (OB stars). One particularly interesting question concerns the phases, during which the classical Be stars occur, which unlike HAe/Be stars, are not…

Solar and Stellar Astrophysics · Physics 2015-05-14 Christophe Martayan , Dietrich Baade , Yves Fremat , Jean Zorec

We present the results of a search for Be stars in six fields centered on the young clusters NGC 330 and NGC 346 in the SMC, and NGC 1818, NGC 1948, NGC 2004 and NGC 2100 in the LMC. Be stars were identified by differencing R band and…

Astrophysics · Physics 2009-10-30 Stefan C Keller , Peter R Wood , Michael S Bessell

We describe a technique to identify Be stars in open clusters using Stromgren b, y, and narrow-band Halpha photometry. We first identify the B-type stars of the cluster using a theoretical isochrone fit to the (b-y, y) color-magnitude…

Astrophysics · Physics 2009-11-10 M. Virginia McSwain , Douglas R. Gies

We present new, accurate positions, spectral classifications, radial and rotational velocities, H-alpha fluxes, equivalent widths and B,V,I,R magnitudes for 579 hot emission-line stars (classes B0 - F9) in the Large Magellanic Cloud which…

Solar and Stellar Astrophysics · Physics 2015-06-05 Warren A. Reid , Quentin A. Parker

We present ultraviolet spectra from the Space Telescope Imaging Spectrograph (STIS) of 12 early B-type stars in the Small Magellanic Cloud (SMC), comprising 9 supergiants and 3 giants. A morphological comparison with Galactic analogues is…

Astrophysics · Physics 2009-11-10 C. J. Evans , D. J. Lennon , N. R. Walborn , C. Trundle , S. A. Rix

The presence of an anomalously large population of Be stars in the young cluster NGC 330 in the SMC has been noted by Feast (1972), Bessell & Wood (1993), Grebel (1996) and most recently Keller et al. (1998). We present results from…

Astrophysics · Physics 2007-05-23 Stefan C. Keller , Michael S. Bessell

We report the discovery of 2 new Be stars, and re-identify one known Be star in the open cluster NGC 6830. Eleven H-alpha emitters were discovered using the H-alpha imaging photometry of the Palomar Transient Factory Survey. Stellar…

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