Tiny galaxy spotted by James Webb Space Telescope sheds light on early universe

Researchers uncover minuscule galaxy forming stars at a remarkable rate, offering insights into cosmic activity shortly after the Big Bang

The team hopes the discovery of a minuscule galaxy could help astronomers learn more about others that came into being post-Big Bang. ESA/Webb, Nasa & CSA

Using the James Webb Space Telescope, space scientists have discovered a small galaxy more than 13 billion years in the past, which formed stars at an exceptionally high rate for its size.

The findings, published in the journal Science, could provide valuable insights into galaxies that were created soon after the inception of the universe.

The telescope's extensive capabilities allowed researchers on the team — led by University of Minnesota, Twin Cities — to observe the galaxy in unprecedented detail.

Senior author and assistant professor Patrick Kelly said: “This galaxy is far beyond the reach of all telescopes except the James Webb and these first-of-their-kind observations are spectacular.”

Gravitational lensing, a phenomenon in which mass bends and magnifies light, enabled the researchers to locate and study the small galaxy, which appeared 20 times brighter than it would without the lensing effect.

Spectroscopy was then used to measure the galaxy's distance and physical properties.

Hayley Williams, the paper's first author and PhD student at the Minnesota Institute for Astrophysics, said: “This discovery can help us learn more about the characteristics of those first galaxies, how they differ from nearby galaxies and how the earlier galaxies formed.”

The James Webb's ability to collect about 10 times more light than the Hubble Space Telescope and its sensitivity to redder, longer wavelengths in the infrared spectrum have opened up new opportunities for research.

James Webb Space Telescope's advanced capabilities

The James Webb Space Telescope (JWST) is a state-of-the-art space observatory, which started operating on December 25, 2021, as a collaborative effort between Nasa, the European Space Agency and the Canadian Space Agency.

It is regarded as the scientific successor to the Hubble, with advanced capabilities designed to explore deeper into the cosmos and uncover new information about the origins of the universe.

The JWST's primary mirror spans 6.5 metres, significantly larger than the Hubble's 2.4m version. This larger mirror enables the JWST to collect more light, making it highly sensitive and allowing it to observe dimmer and more distant objects with unprecedented clarity.

The telescope is optimised for infrared observations, enabling it to "see" through cosmic dust and study the first galaxies, stars and black holes.

Its cutting-edge instruments help to capture high-resolution images, analyse light spectra and gather data on a wide range of cosmic phenomena, from star and galaxy formation to the characterisation of planets outside the solar system.

Positioned nearly 1.5 million kilometres from Earth, the telescope's sunshield, about the size of a tennis court, protects its sensitive instruments during solar orbit from the Sun's heat and light, maintaining optimal operating temperatures.

The JWST has been designed for a mission life of at least 10 years, with potential for extension. Its scientific discoveries are expected to revolutionise our understanding of the universe and address some of the fundamental questions in astronomy and astrophysics.