Valcarce, A. A. R.Catelan, M.Alonso-Garcia, J.Cortés, C.Medeiros, José Renan de2020-05-192020-05-192014MEDEIROS, José Renan de et al. Constraints on helium enhancement in the globular cluster m4 (NGC 6121): the horizontal branch test. The Astrophysical Journal, [s. l.], v. 782, p. 85-93, 2014. ISSN 1538-4357 versão online. DOI https://doi.org/10.1088/0004-637X/782/2/85. Disponível em: http://iopscience.iop.org/article/10.1088/0004-637X/782/2/85/meta. Acesso em: 19 maio 2020.0004-637X (print), 1538-4357 (online)https://repositorio.ufrn.br/jspui/handle/123456789/29026Globular clusters: generalGlobular clusters: individual (M4 = NGC 6121)Hertzsprung–Russell and C–M diagramsStars: abundancesStars: evolutionStars: horizontal-brancharticlehttp://dx.doi.org/10.1088/0004-637X/782/2/85