NASA HUBBLE TELESCOPE CAPTURES IMAGE OF ANCIENT STAR CLUSTER

NASA's Hubble Space Telescope has released an image of NGC 6426, a globular cluster located in the outer halo of the Milky Way. The image was released to mark the United States' 250th anniversary. Globular clusters are tightly packed, nearly spherical collections of stars held together by gravity. The photograph displays stars in red, white and blue hues, resembling a sparkler against a dark sky.

NGC 6426 is estimated to be approximately 13 billion years old, according to NASA, making it one of the oldest known globular clusters in the Milky Way. Astronomers have identified about 150 globular clusters within the galaxy. The cluster's age is only slightly younger than the universe itself, which NASA states is approximately 13.7 billion years old. Stars within globular clusters typically form from the same collapsing cloud of gas and are generally close in age. The vibrant colours in the image represent different wavelengths of light captured through telescope filters, with blue indicating hotter stars and red indicating cooler stars.

The stars in NGC 6426 contain relatively small amounts of elements heavier than hydrogen and helium, a condition astronomers term low metallicity. These chemical conditions closely resemble those found in the young universe, when heavier elements had only begun forming inside massive stars through nuclear fusion, according to NASA. Researchers have identified evidence that NGC 6426 contains two chemically distinct groups of stars. The cluster therefore provides insights into the earliest stages of cosmic history.