This is an intermediate age cluster[6] estimated at 83.2 Myr old.[1] It is a poorly populated cluster with just onered giant member. 33 probable members have been identified,[7] including the variableBe starBZ Crucis.[8] Themetallicity of the cluster, as measured by the abundance of iron, is slightly larger than in the Sun.[7]
^Feinstein, A.; Marraco, H. G. (April 1971), "The open cluster NGC 4609 behind the coalsack",Publications of the Astronomical Society of the Pacific,83: 218,Bibcode:1971PASP...83..218F,doi:10.1086/129108.
^abDrazdauskas, Arnas; et al. (October 2016), "Chemical composition of evolved stars in the young open clusters NGC 4609 and NGC 5316",Monthly Notices of the Royal Astronomical Society,462 (1):794–803,arXiv:1608.08375,Bibcode:2016MNRAS.462..794D,doi:10.1093/mnras/stw1701.
Media related toNGC 4609 at Wikimedia Commons
