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Stunning Hubble Space Telescope Image of a Glittering Globular Cluster

Hubble Space Telescope image of globular cluster NGC 6717. Credit: ESA/Hubble and NASA, A. Sarajedini

This star-studded image from the NASAEstablished in 1958, the National Aeronautics and Space Administration (NASA) is an independent agency of the United States Federal Government that succeeded the National Advisory Committee for Aeronautics (NACA). It is responsible for the civilian space program, as well as aeronautics and aerospace research. It’s vision is “To discover and expand knowledge for the benefit of humanity.””>NASA/ESA Hubble Space TelescopeThe Hubble Space Telescope (often referred to as Hubble or HST) is one of NASA’s Great Observatories and was launched into low Earth orbit in 1990. It is one of the largest and most versatile space telescopes in use and features a 2.4-meter mirror and four main instruments that observe in the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. It was named after astronomer Edwin Hubble.”>Hubble Space Telescope depicts NGC 6717, which lies more than 20,000 light-years from Earth in the constellation Sagittarius. NGC 6717 is a globular cluster, a roughly spherical collection of stars tightly bound together by gravity. Globular clusters contain more stars in their centers than their outer fringes, as this image aptly demonstrates; the sparsely populated edges of NGC 6717 are in stark contrast to the sparkling collection of stars at its center.

The center of the image also contains some interlopers from closer to home. Bright foreground stars close to Earth are surrounded by criss-cross diffraction spikes formed by starlight interacting with the structures supporting Hubble’s secondary mirror.

The area of the night sky which contains the constellation Sagittarius also contains the center of the Milky WayThe Milky Way is the galaxy that contains the Earth, and is named for its appearance from Earth. It is a barred spiral galaxy that contains an estimated 100-400 billion stars and has a diameter between 150,000 and 200,000 light-years.”>Milky Way, which is filled with light-absorbing gas and dust. This absorption of light — which astronomers refer to as extinction — makes studying globular clusters near the Galactic center a challenging endeavor. To determine the properties of NGC 6717, astronomers relied on a combination of Hubble’s Wide Field Camera 3 and the Advanced Camera for Surveys.

Source: SciTechDaily