luminosity
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Is Dark Matter Real?
Here we are, people — it’s finally time to talk about dark matter! I’ve teased this subject in my last few posts. We’ve discussed how the idea originated — with observations of the rotation of galaxies. We’ve touched on the…
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How Big and Bright are Galaxies?
The brightest galaxy in our night sky is the Andromeda Galaxy, our nearest intergalactic neighbor. Hey…notice we’re talking about intergalactic neighbors now? 😀 In most of the posts on this blog, we’ve talked about interstellar neighbors, interstellar space, etc. But…
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How Far Away are Galaxies?
Well, I’ll give you a spoiler: they’re ridiculously far away. Let’s consider for a moment what a light-year actually means. It sounds like a unit of time, but it’s actually the distance that light travels in one Earth year. Think…
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Pulsars as Neutron Stars
For those of you who missed my last couple of posts, allow me to introduce the neutron star: a stellar remnant similar to a white dwarf, but much denser, so dense that its protons and electrons have combined to form…
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How a Star Expands
Meet Betelgeuse, a bright star in the winter constellation Orion. Betelgeuse is a cool red supergiant that we’ll talk about a lot more in just a couple weeks, when we cover variable stars. Not too long ago, it was the…
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The Adult Life of a Star
Stars are like cars. They need fuel to go. And also like cars, they don’t have an infinite supply. But here’s where the metaphor breaks down. They can never refuel. Yup. That’s right. For their entire lives, stars are stuck…
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What is a “Normal” Star?
If we were talking about people, I’d say there’s no such thing as a “normal” person. We’re all weird in our own way — that’s what makes us unique and ourselves. However, there’s such a thing as a functional human…
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The Story of a Newborn Star
What happens when a star is born? A couple of posts ago, I explained how a protostar forms out of a dense cloud core within the interstellar medium. But…wait. What exactly is a protostar again? A protostar forms when one…
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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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Star Mass and Density
What makes a star shine bright? Much earlier on — probably months ago now — I explained how something called the proton-proton chain generates massive amounts of energy within stars, and enables them to fuel whole solar systems. That’s the battery…
