Scientists observed thousands of stars located 23,000 light-years away.
The Hubble Space Telescope continues to study the cosmos like a true veteran explorer. Hubble was used to observe a giant cluster of stars called Pismis 26. This globular cluster is located a staggering 23,000 light-years from Earth. Several thousands of stars glow brightly in this Hubble image against a black backdrop, with a few bright red and blue stars lining the cluster’s edges. Tonantzintla 2 is the dual name given to the cluster by Armenian astronomer Paris Pismis. Pismis discovered it in 1959 at the Tonantzintla Observatory in Mexico. Pismis 26 is located in the constellation Scorpius, a region near the galactic bulge of the Milky Way galaxy.
In this region of our galaxy, there is a dense, spheroidal grouping of stars surrounding the black hole known as Sagittarius A*. A process known as “reddening” occurs within the dust-heavy bulge, where dust scatters shorter wavelengths of blue light while longer wavelengths of red light pass through. A cosmic object’s apparent color is distorted by reddening.
Pismis 26 metallicity
The gravitational attraction between stars in globular clusters holds them together. Furthermore, its shape is almost spherical, and it contains thousands of closely packed stars. Researchers used Hubble’s infrared and visible light to determine Pismis 26’s age, metallicity, and reddening. Pismis 26 stars are highly metallic, which means they contain a high fraction of heavier elements than hydrogen and helium, the most abundant elements in the universe. In particular, the stars contain high nitrogen levels, characteristic of bulge cluster stars. Scientists believe the cluster contains star populations of varying ages. Additionally, Pismis 26 may have lost a significant amount of mass over time due to a gravitational force called the strong inner galaxy tidal field. Galactic bulges are pulled away from their outer layers by force exerted by the inner galaxy. It is estimated that the cluster is 12 billion years old.
