000005844 001__ 5844
000005844 005__ 20220922131021.0
000005844 0247_ $$2DOI$$a10.1051/0004-6361/202244112
000005844 037__ $$aSCART-2022-0090
000005844 100__ $$aMorel, T
000005844 245__ $$aThe Gaia-ESO survey: A spectroscopic study of the young open cluster NGC 3293
000005844 260__ $$c2022
000005844 520__ $$aWe present a spectroscopic analysis of the GIRAFFE and UVES data collected by the Gaia-ESO survey for the young open cluster NGC 3293. Archive spectra from the same instruments obtained in the framework of the ‘VLT-FLAMES survey of massive stars’ are also analysed. Atmospheric parameters, non-local thermodynamic equilibrium (LTE) chemical abundances for six elements (He, C, N, Ne, Mg, and Si), or variability information are reported for a total of about 160 B stars spanning a wide range in terms of spectral types (B1 to B9.5) and rotation rate (up to 350 km s−1). Our analysis leads to about a five-fold increase in the number of cluster members with an abundance determination and it characterises the late B-star population in detail for the first time. We take advantage of the multi-epoch observations on various timescales and a temporal baseline, sometimes spanning ∼15 years, to detect several binary systems or intrinsically line-profile variables. A deconvolution algorithm is used to infer the current, true (deprojected) rotational velocity distribution. We find a broad, Gaussian-like distribution peaking around 200–250 km s−1. Although some stars populate the high-velocity tail, most stars in the cluster appear to rotate far from critical. We discuss the chemical properties of the cluster, including the low occurrence of abundance peculiarities in the late B stars and the paucity of objects showing CN-cycle burning products at their surface. We argue that the former result can largely be explained by the inhibition of diffusion effects because of fast rotation, while the latter is generally in accord with the predictions of single-star evolutionary models under the assumption of a wide range of initial spin rates at the onset of main-sequence evolution. However, we find some evidence for a less efficient mixing in two quite rapidly rotating stars that are among the most massive objects in our sample. Finally, we obtain a cluster age of ∼20 Myr through a detailed, star-to-star correction of our results for the effect of stellar rotation (e.g., gravity darkening). This is significantly older than previous estimates from turn-off fitting that fully relied on classical, non-rotating isochrones.
000005844 594__ $$aNO
000005844 6531_ $$aopen clusters and associations: individual: NGC 3293 
000005844 6531_ $$a stars: fundamental parameters 
000005844 6531_ $$a stars: abundances
000005844 700__ $$aBlazère, A
000005844 700__ $$aSemaan, T
000005844 700__ $$aGosset, E
000005844 700__ $$aZorec, J
000005844 700__ $$aFrémat, Y
000005844 700__ $$aBlomme, R
000005844 700__ $$aDaflon, S
000005844 700__ $$aLobel, A
000005844 700__ $$aF Nieva, M
000005844 700__ $$aPrzybilla, N
000005844 700__ $$aGebran, M
000005844 700__ $$aHerrero, A
000005844 700__ $$aMahy, L
000005844 700__ $$aSantos, W
000005844 700__ $$aTautvaisiene, G
000005844 700__ $$aGilmore, G
000005844 700__ $$aRandich, S
000005844 700__ $$aJ Alfaro, E
000005844 700__ $$aBergemann, M
000005844 700__ $$aCarraro, G
000005844 700__ $$aDamiani, F
000005844 700__ $$aFranciosini, E
000005844 700__ $$aMorbidelli, L
000005844 700__ $$aPancino, E
000005844 700__ $$aC Worley, C
000005844 700__ $$aZaggia, S
000005844 773__ $$nA108$$pAstronomy & Astrophysics$$v665$$y2022
000005844 8560_ $$felodie.brahy@ksb-orb.be
000005844 85642 $$ahttps://www.aanda.org/articles/aa/full_html/2022/09/aa44112-22/aa44112-22.html
000005844 905__ $$apublished in
000005844 980__ $$aREFERD