HST image of the Quintuplet Cluster and the Sickle Nebula. Image size is . The horizontal axis is parallel to Galactic longitude. The net Paschen-α image is in red (see details in Dong et al. 2011), the NICMOS NIC3 F190N image in green, and the NICMOS NIC3 F187N image in blue (continuum and line filter for Paα). The white box around WR 102c marks the field of our SINFONI mosaic. This field is ≈ 1′ from the centre of the Quintuplet Cluster, which is seen as a group of bright blue stars just below the image centre close to the Pistol Nebula (identified by its characteristic shape). The image is based on the data obtained in the Paschen-α survey of the Galactic centre (Wang et al. 2010).