A storm of new stars

The subject of the latest Hubble Picture of the Week is a stormy and highly active spiral galaxy named NGC 1792. Located over 50 million light-years from Earth in the constellation Columba (the Dove), the bright glow of the galaxy’s centre is offset by the flocculent and sparkling spiral arms swirling around it.

NGC 1792 is just as fascinating to astronomers as its chaotic look might imply. Classified as a starburst galaxy, it is a powerhouse of star formation, with spiral arms rich in star-forming regions. In fact, it is surprisingly luminous for its mass. The galaxy is close to a larger neighbour, NGC 1808, and the strong gravitational interaction between the two is believed to be what has stirred up the reserves of gas in this galaxy. The result is a torrent of star formation, concentrated on the side where gravity has a stronger effect. It’s a perfect target for astronomers seeking to understand the complex interactions between gas, star clusters and supernovae in galaxies.

Hubble has shown off this galaxy before, in 2020. This week’s new image includes additional data collected throughout 2025, providing a deeper view of the tumultuous astrophysical activity taking place in the galaxy. Blossoming red lights in the arms mark out so-called H-alpha emission from dense clouds of hydrogen molecules. Stars form within these clouds and shine powerfully with ultraviolet radiation. They ionise the gas around them, causing the gas to emit a very particular red wavelength of light — a tell-tale sign of new stars.

[Image Description: A spiral galaxy, seen partly from the side, with a messy, turbulent appearance. Its disc is made of multiple patchy arms that contain numerous sparkling blue and glowing red regions — star clusters and star-forming nebulae. Thick clumps of dark reddish dust swirl through the disc. The glow of the disc extends out into the dark background, where both distant and nearby stars can be seen.]