Flecks of glimmering gold scattered on a black background. It isn't a description of a new line of clothes, but a beautiful globular cluster that was recently photographed.
The star cluster, named Liller 1, is certainly one of the haute couture models of the sky, but it has been a tricky star system to snap. When we look out at it from Earth, Liller 1's angle from us is almost in line with the center of the Milky Way. This means there's a lot of dust muddying our view of it.
If this didn't make it difficult enough to see, the cluster is also located 3,200 light-years away from the Milky Way and impossible to observe in the visible spectrum. The photograph therefore had to be taken in the infrared range using a powerful infrared camera: the Gemini South Adaptive Optics Imager. Infrared light can penetrate through the dust and reach Earth, which is how the imager can capture this beautiful celestial image.
"Only infrared radiation can travel across these clouds and bring us direct information on its stars," commented study author Emanuele Dalessandro of the University of Bologna. The paper has been published in The Astrophysical Journal.
Liller 1 is a tight sphere of stars known as a globular cluster. The proximity of the stars means that there is the possibility for star collisions. Stellar collisions are otherwise rather rare in the universe since most stars are somewhat solitary. For example, the sun's nearest stellar neighbor is Proxima Centauri, which is a 'mere' 4.2 light-years away. There's no chance of a sun-Proxima Centauri collision anytime soon.
"Although our galaxy has upwards of 200 billion stars, there is so much vacancy between stars that there are very few places where suns actually collide," said Douglas Geisler, principal investigator of the original observing proposal. "The congested overcrowded central regions of globular clusters are one of these places. Our observations confirmed that, among globular clusters, Liller 1 is one of the best environments in our galaxy for stellar collisions."
Hopefully, this globular cluster will be a source of star explosions that we can study. These sorts of explosions, since they are not commonplace, could be the source of exotic galactic objects and a rare chance to examine their origins.
[Via Center for Excellence in Astrophysics and Associated Technologies, The Astrophysical Journal, Arxiv]
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