NGC 247 is a spiral galaxy in the Sculptor Group some 11 million light-years from Earth. This Hubble image shows a zoomed-in view of NGC 247’s central region. Click the picture for a larger-scale version that reveals more distant galaxies. Image credit: ESA/Hubble & NASA.This NASA/ESA Hubble Space Telescope image shows the central region of a spiral galaxy known as NGC 247. NGC 247 is a relatively small spiral galaxy in the southern constellation of Cetus (The Whale). Lying at a distance of around 11 million light-years from us, it forms part of the Sculptor Group, a loose collection of galaxies that also contains the more famous NGC 253 (otherwise known as the Sculptor Galaxy).
NGC 247’s nucleus is visible here as a bright, whitish patch, surrounded by a mixture of stars, gas and dust. The dust forms dark patches and filaments that are silhouetted against the background of stars, while the gas has formed into bright knots known as H II regions, mostly scattered throughout the galaxy’s arms and outer areas.
This galaxy displays one particularly unusual and mysterious feature — it is not visible in the image above, but can be seen clearly in wider views of the galaxy, such as the picture below from ESO’s MPG/ESO 2.2-metre telescope. The northern part of NGC 247’s disc (to the right in the following image) hosts an apparent void, a gap in the usual swarm of stars and H II regions that spans almost a third of the galaxy’s total length.This picture of the spiral galaxy NGC 247 was taken using the Wide Field Imager (WFI) on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile. Image credit: ESO.There are stars within this void, but they are quite different from those around it. They are significantly older, and as a result much fainter and redder. This indicates that the star formation taking place across most of the galaxy’s disc has somehow been arrested in the void region, and has not taken place for around one billion years. Although astronomers are still unsure how the void formed, recent studies suggest it might have been caused by gravitational interactions with part of another galaxy.
Spiral galaxies oriented face on to Earth offer spectacular views while giving astronomers a better chance to monitor the frequency of supernova blasts. A prime example is a galaxy known as NGC 5468 where at least five stellar explosions have been spotted.
This Hubble image is of the peculiar galaxy NGC 1487, lying about 30 million light-years away. We are witnessing the possible merger of several dwarf galaxies into a new single galaxy. Its appearance is dominated by large areas of bright blue stars, illuminating the patches of gas that gave them life. This burst of star formation may well have been triggered by the merger.
This image shows a lonely galaxy known as Wolf-Lundmark-Melotte, or WLM for short. Although considered part of our Local Group of dozens of galaxies, WLM stands alone at the group’s outer edges as one of its most remote members. In fact, WLM is so small and secluded that it may never have interacted with any other galaxy in the history of the universe.
