Be stars and binaries in the field of the SMC open cluster NGC 330 with VLT-FLAMES

Martayan, Christophe; Floquet, M.; Hubert, A. M.; Gutiérrez‐Soto, J.; Fabregat, J.; Neiner, C.; Mekkas, Malek

doi:10.1051/0004-6361:20077390

Cited by 58 publications

(77 citation statements)

References 44 publications

(88 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With the help of SIMBAD, the previously known Be stars and those found by Album were compared, and the Hα equivalent widths and line strengths were taken from Hummel et al (1999Hummel et al ( , 2001); Martayan et al (2007a), which were similar to the WFI observations of NGC 6611 by Martayan et al (2008). The results are shown in Fig.…”

Section: Efficiency Of Hα Emission Detectionmentioning

confidence: 99%

“…Circumstellar disks of Be stars have been reported (Wisniewski & Bjorkman 2006;Wisniewski et al 2007a;Martayan et al 2007a) to be closer to the central star at lower metallicity, so that the circumstellar extinction towards lowinclination Be stars would be increased. However, as explained above, the radii of the stars are smaller, thereby partly offsetting the claimed difference in geometry.…”

Section: Colour Excesses Of Emission-line Starsmentioning

confidence: 99%

“…Detection efficiency in equivalent width (top) and peak line strength relative to the continuum (bottom) of Hα emission with WFI slitless spectra. The Hα data are from Hummel et al (1999Hummel et al ( , 2001 and Martayan et al (2007aMartayan et al ( , 2008 and/or UCAC2, USNO catalogues were utilized. In this way, the coordinates of the 7,867 SMC stars mentioned in Sect.…”

Section: Astrometry and Correlation With Oglementioning

confidence: 99%

“…In the Galaxy, only one such case has been found so far (μ Cen, Rivinius et al 1998). However, several photometrically multi-periodic candidates were identified by Martayan et al (2007a) and Diago et al (2008) in the SMC. The latter authors report an order of magnitude higher incidence of pulsations among Be stars than in B stars without emission lines.…”

Section: Evolution and Agementioning

confidence: 99%

See 3 more Smart Citations

A slitless spectroscopic survey for Hαemission-line objects in SMC clusters

Martayan

Baade

Fabregat³

2010

A&A

Self Cite

View full text Add to dashboard Cite

Context.A fair fraction of all single early-type stars display emission lines well before their supergiant phase. Very rapid rotation is necessary for these stars to form rotationally supported decretion disks. However, it is unknown whether and which other parameters may be important. Aims. We assess the roles of metallicity and evolutionary age in the appearance of the so-called Be phenomenon. Methods. Slitless CCD spectra were obtained covering the bulk (about 3 square degrees) of the Small Magellanic Cloud. For Hα line-emission twice as strong as the ambient continuum, the survey is complete to spectral type B2/B3 on the main sequence. About 8120 spectra of 4437 stars were searched for emission lines in 84 open clusters, and 370 emission-line stars were found, among them at least 231 close to the main sequence. For 176 of them, photometry is available from the OGLE database. For comparison with a higher-metallicity environment, the Galactic sample of the photometric Hα survey by McSwain & Gies (2005, ApJS, 161, 118) was used.Results. Among early spectral sub-types, Be stars are more frequent by a factor ∼3-5 in the SMC than in the Galaxy. The distribution with spectral type is similar in both galaxies, i.e., not strongly dependent on metallicity. The fraction of Be stars does not seem to vary with local star density. The Be phenomenon mainly sets in towards the end of the main-sequence evolution (this trend may be more pronounced in the SMC); but some Be stars already form with Be-star characteristics. In small subsamples (such as single clusters), even if they appear identical, the fraction of emission-line stars can deviate drastically from the mean. Conclusions. In all probability, the fractional critical angular rotation rate, Ω/Ω c , is one of the main parameters governing the occurrence of the Be phenomenon. If the Be character is only acquired during the course of evolution, the key circumstance is the evolution of Ω/Ω c , which is not only dependent on metallicity but differently so for different mass ranges. As a result, even if the Be phenomenon is driven basically by a single parameter (namely Ω/Ω c ), it can assume a complex multi-parametric appearance. The large cluster-to-cluster differences, which seem stronger than all other variations, serve as a caveat that this big picture may undergo significant second-order modulations (e.g., pulsations, initial angular momentum, etc.).

show abstract

Section: Efficiency Of Hα Emission Detectionmentioning

confidence: 99%

Section: Colour Excesses Of Emission-line Starsmentioning

confidence: 99%

Section: Astrometry and Correlation With Oglementioning

confidence: 99%

Section: Evolution and Agementioning

confidence: 99%

See 2 more Smart Citations

A slitless spectroscopic survey for Hαemission-line objects in SMC clusters

Martayan

Baade

Fabregat³

2010

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…The Be phenomenon is known to be enhanced at low metallicities causing outbursts to last longer and have larger amplitudes Evans et al (2006), ( * * * ) Martayan et al (2007). Notes.…”

Section: Irregular Variablesmentioning

confidence: 99%

Variability of massive stars with known spectral types in the Small Magellanic Cloud using 8 years of OGLE-III data

Kourniotis

Bonanos

Soszyński

et al. 2014

A&A

View full text Add to dashboard Cite

We present a variability study of 4646 massive stars in the Small Magellanic Cloud (SMC) with known spectral types from the catalog of Bonanos et al. (2010) using the light curves from the OGLE-III database. The goal is to exploit the time domain information available through OGLE-III to gain insight into the processes that govern the evolution of massive stars. This variability survey of massive stars with known spectral types is larger than any previous survey by a factor of 7. We find that 60% of our sample (2766 stars) show no significant variability and 40% (1880 stars) exhibit variability distributed as follows: 807 stars display low-amplitude stochastic variability with fluctuations in the I-band of up to 0.05 mag, 443 stars present irregular variability of higher amplitude (76% of these are reported as variables for the first time), 205 are eclipsing binaries (including 101 newly discovered systems), 50 are candidate rotating variables, 126 are classical Cepheids, 188 stars exhibit short-term sinusoidal periodicity (P < 3 days) making them candidate "slowly pulsating B stars" and non-radial Be pulsators, and 61 periodic stars exhibit longer periods. We demonstrate the wealth of information provided in the time domain, by doubling the number of known massive eclipsing binary systems and identifying 189 new candidate early-type Be and 20 Oe stars in the SMC. In addition, we find that ∼80% of Be stars are photometrically variable in the OGLE-III time domain and provide evidence that short-term pulsating stars with additional photometric variability are rotating close to their break-up velocity.

show abstract

The Young Massive Small Magellanic Cloud Cluster NGC 330 Observed with MUSE

Bodensteiner

2022

Observational Imprints of Binary Evolution on B- And Be-Star Populations

View full text Add to dashboard Cite

Be stars and binaries in the field of the SMC open cluster NGC 330 with VLT-FLAMES

Cited by 58 publications

References 44 publications

A slitless spectroscopic survey for Hαemission-line objects in SMC clusters

A slitless spectroscopic survey for Hαemission-line objects in SMC clusters

Variability of massive stars with known spectral types in the Small Magellanic Cloud using 8 years of OGLE-III data

The Young Massive Small Magellanic Cloud Cluster NGC 330 Observed with MUSE

Contact Info

Product

Resources

About