Stars are often born in clusters or groups, in giant clouds of gas and dust. Astronomers have studied two star clusters using Nasa’s Chandra X-ray Observatory and infrared telescopes – and the results show that the simplest ideas for the birth of these clusters cannot work.
This composite image shows one of the clusters, NGC 2024, which is found in the centre of the so-called Flame Nebula about 1 400 light-years from Earth. In this image, X-rays from Chandra are seen as purple, while infrared data from the Spitzer Space Telescope are coloured red, green and blue.
Image credit: Nasa