A few days ago I wrote about a galaxy that was tough to see because of Milky Way field stars. But our galaxy is far more than just a bunch of stars smattered about. There is also a huge amount of gas and dust with varying temperatures. Some of the hotter and more illuminated gas and dust are what make nebulae so lovely in space. But the cold gas and dark dust that is just out floating in the cold interstellar medium? That stuff gets in the way. A normal image of interacting galaxies M81 and M82 would try to hide the...
We know that solar systems form in a disk shape, with the star forming in the middle and any other rocks, presumably planets, form out from the center in whatever dust and gas remains. But what about the space between stars? Is it truly empty? And if there is something out there, how could we find it? How did it get there? For years, astronomers and chemists (believe it or not) have been trying to answer these questions and more. The specific problem is that when we take a spectrum of a distant star, we see a collection of 400...
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...
In Canis Major, nearly 12,000 light years from Earth, lies an emission nebula that always makes me think of a particular comic book character. NGC 2359 is 30 light years across, and is colloquially known as Thor’s Helmet. The complex structure of Thor’s helmet consists of bubbles and filaments, and is due to a series of bursts from the massive star HD 56925. This star is a rare Wolf-Rayet star, which consistently expels its outer layers of gas at high velocities, and is characterized by its very high temperature. The blue bubble in the above image is a result of...
