Italian astronomers studied the young open cluster of NGC 6530 by performing a statistical analysis of its properties. Open clusters emerging from a single giant molecular cloud are groups of several thousand stars with a weak gravitational coupling. These stars are endowed with a single age, chemical composition and distance from the Earth, therefore they play the role of wonderful laboratories for studying the birth and evolution of stars.
NGC 6530 found in the 17th century. This is a young open cluster with an age of several million years. Lives in the Laguna Nebula. The cluster stands out due to the complex morphology and history of stellar birth.
NGC 6530 accommodates low-mass main-sequence stars, thereby becoming bright X-ray sources. This allowed scientists to identify a large population of 2500 candidates for members of the cluster. However, the list remains incomplete, because each of the previously used methods is biased. Therefore, the researchers in the new work decided to assemble a comprehensive list of candidates for members of NGC 6530 using various methods. This made it possible to increase the census of participants to more than 3,500 stars. Methods include X-ray data, hydrogen alpha radiation, excess near infrared and ultraviolet, and Gaia astrometry. In addition, we applied our own method for photometric selection of cluster members of the up-main M-type sequence.
Researchers reported that out of 3,675 candidates, only 711 meet more than one criterion. But they believe that more than 2,700 objects are true members of NGC 6530. The new number is 2,728 stars, including objects with 0.2-0.4 solar masses. The team also found that the distance to the cluster is about 4,300 light years.