- The Hubble Space Telescope operated by NASA and the ESA has returned another stunning image of an area of space.
- The globular star cluster known as NGC 1805 is a collection of stars of varying ages and intensities.
- The blue stars burn hotter and put off UV light, while the red stars put off infrared light, and Hubble can capture both thanks to its position high above Earth’s atmosphere.
The image above might look like a perfectly-timed capture of a firework exploding in midair, but it’s actually a distant collection of stars called NGC 1805. It’s what is called a globular cluster of stars, and you can see why. The image was captured by NASA’s Hubble Space Telescope, and aside from being a gorgeous piece of stellar eye candy, it’s also an awesome example of why space telescopes are so important to our understanding of space.
As the Hubble website explains, the cluster is a densely packed collection of stars that are much closer than any star is to our own Sun. The stars are “100 to 1,000 times closer” to one another than any other star is to our Sun, which is pretty incredible.
With so many stars occupying a single area, you might be tempted to wonder what kinds of planets are orbiting them. If planets were orbiting these stars, they’d have an incredible view, but the Hubble team says that the odds are low. When stars form and such close proximity, planetary systems surrounding those stars are “unlikely,” according to scientists.
As for the incredible color variations we see in the image, that’s actually a byproduct of the way the image was captured as well as the differences in the stars themselves. Stars that show up blue in the image are detected using near-ultraviolet light. They burn hotter than the orange and red stars, which put off more near-infrared light. The fact that we can see all of these stars is thanks to Hubble being a space telescope, rather than ground-based.
The full-sized image is available here:
Earth’s atmosphere is really good at absorbing most UV light. Some UV light still sneaks through, but ground-based telescopes couldn’t capture this image in the same way that a space telescope can. Without having to deal with Earth’s atmosphere, Hubble can detect the UV light as well as the infrared light, painting a much clearer picture of this particular area of space.
“Usually, globular clusters contain stars which are born at the same time; however, NGC 1805 is unusual as it appears to host two different populations of stars with ages millions of years apart,” the Hubble team explains. “Observing such clusters of stars can help astronomers understand how stars evolve, and what factors determine whether they end their lives as white dwarfs, or explode as supernovae.”