Chandra Observatory Reveals Westerlund 1 Super Star Cluster

NASA's Chandra X-ray Observatory has recently captured images of the super star cluster Westerlund 1, which is located about 13,000 light-years away from Earth. This cluster, considered one of the largest and nearest to our planet, is between 3 million and 5 million years old. It is unique in that it contains a mass that is between 50,000 and 100,000 times that of the Sun, making it one of the few remaining super star clusters in the Milky Way.

Astronomers from the Italian National Institute of Astrophysics in Palermo are leading a project called the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS), which aims to study this active star-producing region in more detail. The Chandra X-ray Observatory observed Westerlund 1 for approximately 12 days, providing valuable data to researchers. The images captured reveal young stars as white and pink, along with diffused heated gas shown in various colors indicating increasing temperatures.

The new data from EWOCS has significantly increased the number of known X-ray sources in Westerlund 1. Previously, Chandra had detected 1,721 sources, but the EWOCS data has revealed nearly 6,000 X-ray sources, including faint stars with lower masses than the Sun. This new information has allowed astronomers to study the evolution of stars across various masses, providing insights into the era when most stars in the galaxy formed.

One notable discovery from the new data is that 1,075 stars are densely packed into the core of Westerlund 1 within a four light-year radius. This concentration of stars provides researchers with a unique opportunity to study the influence of a super star cluster's environment on star and planet formation. Additionally, the diffuse emission in the EWOCS data has led to the first detection of a halo of hot gas around the center of Westerlund 1, which is crucial for understanding the cluster's formation and evolution.

Westerlund 1 presents an ideal target for investigating the internal workings of super star clusters, offering valuable information on how such cosmic star factories operate. The unique characteristics of this cluster, along with the proximity to Earth, make it an essential area of study for astronomers seeking to better understand the processes of star and planet formation. The results of the EWOCS project have been detailed in a paper published in the journal Astronomy and Astrophysics in February.