NGC 247 is a relatively small spiral galaxy in the southern constellation of Cetus (The Whale), part of the Sculptor Group around 11 million light-years from us. NGC 247 displays one particularly unusual and mysterious feature — an apparent void in the usual swarm of stars and H II regions in the northern part of its disc that spans almost a third of the galaxy’s total length.
A dwarf galaxy discovered close to the famous Sculptor Galaxy (NGC 253) by Australian astrophotographer Michael Sidonio has been studied in detail by the 8-metre Subaru Telescope in Hawaii. This fruitful collaboration between amateur and professional astronomers has revealed that the dwarf galaxy, now known as NGC 253-dw2, is being disrupted by the nearby giant spiral.
The Sculptor Dwarf Galaxy, pictured in this new image from ESO’s La Silla Observatory, is a close neighbour of the Milky Way. This galaxy is much smaller and older than ours, making it a valuable subject for studying both star and galaxy formation in the early universe. However, due to its faintness, studying this object is no easy task.
Starburst galaxies transmute gas into new stars up to 1,000 times faster than typical spiral galaxies like the Milky Way. To try and understand why, an international team of astronomers used the Atacama Large Millimeter/submillimetre Array (ALMA) to dissect a cluster of star-forming clouds at the heart of NGC 253 — one of the nearest starburst galaxies.