The result: a vivid landscape of galaxies along with more than a dozen newly found time-varying objects
This panchromatic view of galaxy cluster MACS0416 was created by combining infrared observations from the NASA/ESA/CSA James Webb Space Telescope with visible-light data from the NASA/ESA Hubble Space Telescope. To make the image, in general the shortest wavelengths of light were colour-coded blue, the longest wavelengths red, and intermediate wavelengths green. The resulting wavelength coverage, from 0.4 to 5 microns, reveals a vivid landscape of galaxies that could be described as one of the most colourful views of the universe ever created.
MACS0416 is a galaxy cluster located about 4.3 billion light-years from Earth, meaning that the light from it that we see now left the cluster shortly after the formation of our Solar System. This cluster magnifies the light from more distant background galaxies through gravitational lensing. As a result, the research team has been able to identify magnified supernovae and even very highly magnified individual stars.
Those colours give clues to galaxy distances: the bluest galaxies are relatively nearby and often show intense star formation, as best detected by Hubble, while the redder galaxies tend to be more distant, or else contain copious amounts of dust, as best detected by Webb. The image reveals a wealth of details that it is only possible to capture by combining the power of both space telescopes.
This image of galaxy cluster MACS0416 highlights one particular gravitationally lensed background galaxy, which existed about 3 billion years after the big bang. That galaxy contains a transient, or object that varies in observed brightness over time, that the science team nicknamed “Mothra.” Mothra is a star that is magnified by a factor of at least 4,000 times. The team believes that Mothra is magnified not only by the gravity of galaxy cluster MACS0416, but also by an object known as a “milli-lens” that likely weighs about as much as a globular star cluster