Apresentamos neste trabalho uma breve revisão sobre o método de trânsito na detecção de exoplanetas. O trânsitoé uma técnica baseada na redução do brilho de uma estrela quando o exoplaneta passa na sua frente percorrendo o seu disco, com respeitoà linha de visada. O método de trânsitoé responsável por 23% das detecções de exoplanetas. Nesse sentido, discutimos de forma pedagógica os detalhes da técnica, deduzindo as principais equações. Por fim, a aplicação do método na detecção do exoplaneta COROT-1b foi analisado. Palavras-chave: método do transito; exoplanetas This issue reports a brief review about transit method of detecting extrasolar planet (exoplanet). When a exoplanet crosses (transits) in front of its host star's disk along the line of sight, then the observed visual brightness of the star drops by a small amount. The transit method is responsible for 23% of some important new discoveries of exoplanets. In this sense, we explain didactically the conceptual and calculational details of transit method. As a result of application of the transit method, we applied it to exoplanet COROT-1b. Keywords: transit method; exoplanets IntroduçãoA detecção de exoplanetas constitui um dos temas da Astrofísica que tem recebido muito destaque noś ultimos anos. As principais agências internacionais que realizam pesquisas astronômicas, ESO, NASA e ESA, fomentam projetos que possuem como principal meta a detecção de planetas extra-solares. Uma das técnicas de detecção de exoplanetas que tem crescidoé o método de trânsito [1,2]. Trânsito, eclipse e ocultação são essencialmente o mesmo fenômeno, pois ocorrem quando um objeto astronômico passa na frente de outro com respeitoà linha de visada. O parâmetro que os diferenciaé a distância angular do astro até o observador. Durante um eclipse, os dois objetos são de tamanhos angulares comparáveis, como por exemplo a Lua eclipsando o Sol. Na ocultação, a distância angular de um dos objetosé pequena comparado ao outro, como a Lua * Endereço de correspondência: wytler.cordeiro@gmail.com. ocultando uma estrela. O trânsitoé o oposto da ocultação, o objeto que possui tamanho angular menor fica a frente do outro objeto, como exemplo, temos a projeção de um dos satélites de Júpiter no disco do planeta [3,4].O trânsito possui uma longa história de interesse para os astrônomos.

Context. In the last 15 years different ground-based spectroscopic surveys have been started (and completed) with the general aim of delivering stellar parameters and elemental abundances for large samples of Galactic stars, complementing Gaia astrometry. Among those surveys, the Gaia-ESO Public Spectroscopic Survey, the only one performed on a 8m class telescope, was designed to target 100,000 stars using FLAMES on the ESO VLT (both Giraffe and UVES spectrographs), covering all the Milky Way populations, with a special focus on open star clusters. Aims. This article provides an overview of the survey implementation (observations, data quality, analysis and its success, data products, and releases), of the open cluster survey, of the science results and potential, and of the survey legacy. A companion article reviews the overall survey motivation, strategy, Giraffe pipeline data reduction, organisation, and workflow. Methods. We made use of the information recorded and archived in the observing blocks; during the observing runs; in a number of relevant documents; in the spectra and master catalogue of spectra; in the parameters delivered by the analysis nodes and the working groups; in the final catalogue; and in the science papers. Based on these sources, we critically analyse and discuss the output and products of the Survey, including science highlights. We also determined the average metallicities of the open clusters observed as science targets and of a sample of clusters whose spectra were retrieved from the ESO archive.Results. The Gaia-ESO Survey has determined homogeneous good-quality radial velocities and stellar parameters for a large fraction of its more than 110,000 unique target stars. Elemental abundances were derived for up to 32 elements for targets observed with UVES. Lithium abundances are delivered for about 1/3 of the sample. The analysis and homogenisation strategies have proven to be successful; several science topics have been addressed by the Gaia-ESO consortium and the community, with many highlight results achieved. Conclusions. The final catalogue will be released through the ESO archive in the first half of 2022, including the complete set of advanced data products. In addition to these results, the Gaia-ESO Survey will leave a very important legacy, for several aspects and for many years to come.

We 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 Myrs 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.