Crux dominant stars, descending in clockwise order by magnitude: Beta, Gamma (one of the closest red giants to Earth), Delta and Epsilon Crucis. Many of these brighter stars are members of the Scorpius–Centaurus Association, a large but loose group of hot blue-white stars that appear to share common origins and motion across the southern Milky Way. The constellation contains four Cepheid variables that are each visible to the naked eye under optimum conditions. Crux also contains the bright and colourful open cluster known as the Jewel Box (NGC 4755) and, to the southwest, partly includes the extensive dark nebula, known as
Flag of Brazil the fourth magnitude, and a tenth of a module (0.10m) for the fifth magnitude. Paulo Araújo Duarte of the Federal University of Santa Catarina claims that "the creators of our republican flag intended to represent the stars in the sky at Rio de Janeiro at 8:30 in the morning on 15 November 1889, the moment at which the constellation of the Southern Cross was on the meridian of Rio de Janeiro and the longer arm [of the cross] was vertical". Another article, citing "O Céu da Bandeira (The Sky of the Flag)", by J. R. V. Costa, says the exact