James Webb Telescope finds 104 magnified stars in Dragon galaxy

Record number of detections found

The team led by José María Palencia compared images collected between 2022 and 2024 to spot brightness changes. They corrected for slight angle differences to avoid false signals during the subtraction process. Researchers removed bright unrelated objects like the galaxy core before measuring noise levels carefully. This method allowed them to detect 104 unique stellar events which doubles the previous record of 44.

Gravitational lensing creates microcaustics

Light from the Dragon galaxy stretches across a massive cluster named Abell 370 at redshift 0.725. A portion of the galaxy forms an arc known as the Dragon arc due to gravitational lensing. Small distortions from cluster stars break caustic lines into microcaustics that focus light dramatically. Individual stars drift across these lines causing their brightness to increase hundreds or thousands of times normally.

Supergiants dominate the sample

Only the most luminous stars appear in these events because fainter ones remain hidden from view. The detected stars are almost always supergiants coming in two main types called blue and red varieties. Blue supergiants shine mostly at short wavelengths while red supergiants emit mostly in the near-infrared spectrum. The ratio between these two types reveals details about the galaxy's stellar population composition.