'4,600 light-years away': NASA's Chandra X-ray telescope discovers 'danger zone' around a large star cluster

Produced by: Tarun Mishra

Discovery of 'Danger Zones'

Using the Chandra X-ray Observatory and data from the retired Spitzer Space Telescope, NASA astronomers identified hazardous regions where planets struggle to form around young stars.

Credit: NASA

Focus on Cygnus  OB2 Cluster

The observations were centred on Cygnus OB2, a large star cluster about 4,600 light-years away, containing massive stars alongside thousands of lower-mass stars.

Creating a Stellar Mosaic

By compiling long-term images from Chandra and Spitzer, researchers created a detailed mosaic showing high-energy X-rays emitted between stars, enabling a comprehensive inventory of young stars in the cluster.

Influence of High-Energy Radiation on Protoplanetary Disks

The study highlighted that high-energy ultraviolet and X-ray radiation from massive stars disrupts the protoplanetary disks of gas and dust around young stars, which are essential for planet formation.

Credit: University of Copenhagen/Lars Buchhave

Photoevaporation Process

This radiation causes disk material to evaporate—a process called photoevaporation. Disk winds then push this evaporated matter away, accelerating disk depletion and reducing planet formation potential.

Credit: NASA

Impact on Disk Longevity

For stars similar to the Sun, protoplanetary disks can last 5-10 million years. However, in Cygnus OB2, high-energy radiation from massive stars speeds up this depletion, shortening the window for planet formation.

Credit: NASA

Variation in Disk Dissipation Across Cluster

Disk retention rates differed across Cygnus OB2. In less crowded regions, 40% of young stars still have disks, whereas in denser regions with more radiation, this drops to 18%, and in some areas, as low as 1%.

Credit: chandra x-ray observatory

Complementary  Research Findings

Another study using Chandra data showed high-energy X-rays in Cygnus OB2 are generated by disk wind collisions from massive stars, further highlighting the turbulent conditions that hinder planet formation in these 'danger zones.'