Emma
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From Cold Cloud to Hot Protostar
Paradoxically, stars begin in the galaxy’s coolest places: the dense giant molecular clouds (or GMCs). This is not quite the paradox it seems, as in the beginning, stars require little else but gravity to form. And that’s really quite lucky, because…
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How are Stars Born?
Astronomers have discovered that the clouds of gas and dust — the interstellar medium (ISM) — found between the stars are made of the same materials as the stars themselves. In fact, hydrogen is the most common element in both…
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Where Did the Interstellar Medium Come From?
Contrary to popular belief, space is not empty. The space between the stars is filled with clouds of dust and gas. And this space — the interstellar medium — is incredibly beautiful and fascinating. I often refer to the interstellar…
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What is Coronal Gas?
Stars are hot. Space is cold. We’re all familiar with that, right? Ok, good. Technically, it’s more complicated than that. Space isn’t completely frigid — absolute zero, the temperature at which there is no heat whatsoever, is purely theoretical and not…
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What are Molecular Clouds?
Meet the Pillars of Creation, a photograph taken by the Hubble Telescope in 1995. These apparent “pillars” of dust and gas are what we call molecular clouds. And this region of clouds in space is aptly named: it’s where stars are…
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What is the Intercloud Medium?
Stars are like headlights in a fog bank that’s impossibly thick in some places, and so thin as to be transparent in others. Sometimes, we get lucky enough for starlight to light up the fog. Other times, stars shine straight…
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What are Cool Clouds?
Have you ever driven through fog? I’m going to guess, for the sake of this post, that you have. And if you haven’t…well, I think the image above should give you a pretty good idea of what it’s like. Low…
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Radiation from Interstellar Dust
Does this sight look familiar? If you’ve had the opportunity to observe the night sky from a dark place, far away from the light pollution of the city, on a clear night, you might have seen this before. It’s the…
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Interstellar Spectra
I often refer to what we call the interstellar medium as the galaxy’s “backstage,” and I do that for a reason: for the most part, we can’t see it. The backstage of any theater isn’t part of the show. You, as…
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Extinction and Reddening of Starlight
Take a wild guess: What do you think this image is showing you? If you said it looks like a giant black hole in space, I don’t blame you. I also don’t blame you if you thought it looks like…
