It sounds like something out of a science fiction novel. The incredible and rare dark star cluster, hiding the evil super villain’s headquarters. A dark star cluster is something I would imagine as a spooky, eerie type of place where everything you see changes when you enter its space. Science fiction aside, a dark star cluster is real, and it’s a new type of cluster that is similar to the mighty dense globular clusters that orbit most galaxies. Globular clusters orbit in a halo of space around the centres of galaxies, and though our Milky Way harbours 150 of them,...
Massive star clusters can pop into existence in a matter of a few million years, a very short period of time on astronomical time scales. They consist of hundreds or thousands of massive, bright, hot stars that will live relatively short lives of a few hundred millions of years. Using the Atacama Large Millimeter/Submillimeter Array (ALMA), astronomers have discovered a vanishingly rare molecular cloud of highly dense gas, containing no stars. It is poised to become a massive star cluster, and we found it in its infancy. “We may be witnessing one of the most ancient and extreme modes of...
Globular Clusters are tightly packed collections of hundreds of thousands of very old stars, spherically distributed around the Milky Way Galaxy. They undergo little change, have nearly no gas, and have a stellar density way higher than the rest of the Galaxy. The first one discovered, in 1665, is messier 22, one of the most well studied, easily visible, and interesting globular clusters. Based on observations, this globular cluster contains at least two black holes. It is also one of only three globular clusters ever found to host a planetary nebula, a gaseous shell emitted by a dying star with...
It’s not often that we find new star clusters within our own Galaxy. Technology has been good enough to see the stars in the Milky Way for decades, and the grunt work in identifying and cataloguing local clusters is more or less finished, but occasionally we get lucky. A tiny and extremely distant globular star cluster has been found in the outskirts of the far side of our home galaxy. Currently named Kim 2, it pales in comparison to the other 150 Milky Way globular clusters, containing 10-20 times fewer stars and having less than half the stellar density. The...
When I do Planetarium shows, one of the things I like to talk about during the Milky Way – Andromeda collision that will happen in 70 Mlllion years, is the fact that very few stars will actually hit each other. Yet we still call it a ‘Galaxy collision.’ One of the questions I always get is “Will the Earth survive this?” I usually ask the audience. The response is usually a unanimous ‘No way!” And then I tell them how big Galaxies are and they can’t believe how unlikely it is that the solar system will be affected. Consider the...
