yes, the Sony DSC-RX100M4 has an aperture. It has a maximum aperture range of F1.8 (wide angle) to F2.8 (telephoto). This allows good control over depth of field and low light performance. In terms of photographing stars, the camera can capture images of the night sky, but it may not be the best choice for astrophotography. You can find more information about the technical specifications on our support page.