Red, white, and blue stars glitter like a sparkler being waved on a dark night in this new image from NASA’s Hubble Space Telescope. NASA released this image to celebrate the United States’ 250th anniversary, as the agency carries forward America’s legacy of exploration.
Located in the outer halo of our Milky Way galaxy, globular cluster NGC 6426 is a spherical collection of stars bound together by their mutual gravity, one of 150 known globular clusters in our galaxy. These groups of stars are thought to form as a unit from the same collapsing cloud of gas, and thus the stars in them typically have similar ages. The stars in globular clusters tend to be ancient. At approximately 13 billion years old, NGC 6426 is one of the Milky Way’s oldest globular clusters and almost as old as the universe itself (13.7 billion years).
In this image, blue indicates the shorter wavelengths that are visible light, while red depicts the longer wavelengths of visible light, as well as some near-infrared light. Colors in Hubble images are chosen based on standard image processing techniques to best represent the wavelengths of light that pass through the filters used in the observation. Because the color and temperature of stars are directly related, we know that the blue stars in this image are hotter and the red stars are cooler.
