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
Crux in Chinese astronomy Crux in Chinese astronomy The modern constellation Crux is not included in the Three Enclosures and Twenty-Eight Mansions system of traditional Chinese uranography because its stars are too far south for observers in China to know about them prior to the introduction of Western star charts. Based on the work of Xu Guangqi and the German Jesuit missionary Johann Adam Schall von Bell in the late Ming Dynasty, this constellation has been classified as one of the 23 Southern Asterisms (近南極星區, "Jìnnánjíxīngōu") under the name Cross (十字架, "Shízìjià"). Possibly Acrux (Alpha Crucis), Mimosa (Beta Crucis) and Gacrux (Gamma Crucis) are