What are Seyfert Galaxies?

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Meet NGC 1566, an intermediate spiral galaxy in the constellation Fornax.

To the human eye, this galaxy looks almost like any other spiral: It has a central nucleus and spiral arms, and it’s full of gas and dust. As an “intermediate” spiral, its nucleus has a bit of a barred structure, but not a strong one. All that’s pretty normal, as galaxies go.

But if we look a little closer, we see that this galaxy’s nucleus is unusually bright, especially for its small size.

As it turns out, NGC 1566 isn’t so normal after all…

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Galaxies Demystified

/ Emma / 3 Comments

From the smallest of irregular and dwarf galaxies, to the most spectacular of spirals, to the most massive of ellipticals, there’s no denying that galaxies are incredible objects.

On this blog, we’ve covered a great deal of information about galaxies. We’ve followed their stories from the dawn of time in the universe to the present day, and we’ve explored all their different shapes and sizes, their masses, and the forces that shape their evolution.

If it seems like a lot, I understand.

So, let’s round up what we know and boil it down to a summary. Hopefully I can make galaxies more easily digestible!

(Though I do hope none of you actually try to eat one… 😉)

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How Galaxies Evolve

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Ever since astronomers realized that the mysterious, fuzzy objects known as “spiral nebulae” were, in fact, separate galaxies beyond our own, we’ve sought to understand the stories of galaxies.

We’ve since discovered that most galaxies are found in galaxy clusters. There are two types: rich clusters, which are home to thousands of galaxies, and poor clusters like our own “Local Group,” which are home to only a few dozen to a few hundred galaxies.

We’ve also discovered that collisions between galaxies are quite common, and can drastically alter their shapes.

And we’ve observed something even more curious. Spiral galaxies, like our own Milky Way, are most often found in poor clusters. Rich clusters are dominated by elliptical galaxies.

It would seem that spiral galaxies thrive best in uncrowded galactic environments.

But what can that tell us about galactic evolution?

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When Galaxies Collide

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Meet the Whirlpool Galaxy, a spiral galaxy in the constellation Canes Venatici. This was actually the first galaxy to be classified as a spiral.

Specifically, the Whirlpool Galaxy is what we call a grand-design spiral: a galaxy with a very distinct pattern of two spiral arms. It was discovered by Charles Messier way back in 1773 and added to the Messier catalog as a “spiral nebula,” way back before astronomers knew what galaxies were.

But…hold on just a second.

Anybody notice there isn’t just one galaxy here?

The Whirlpool’s companion is known as NGC 5195–or, if you prefer, M51b. Together, the two galaxies are designated in the Messier catalog as M51.

We are, in fact, viewing them in the aftermath of a collision that drastically altered the shape of both galaxies. Both of these were likely once uniform disk galaxies with no spiral arms.

So, what happens when galaxies collide? And does this happen often?

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Exploring Galaxy Clusters

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What if we were to travel beyond our own Milky Way Galaxy, and foray out into the galactic wilderness of deep space? What do you think we’d expect to find?

Would we find galaxies spread out apart from one another, little islands unto themselves? Or would we find them clustered in groups?

Well…I guess the post title kinda gave it away, huh?

Hang on tight, because it’s time for a tour of galaxy clusters!

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Updates!

/ Emma / 2 Comments

Alright, so, a couple things…

Yes, I’m back!

I spent most of 2023 working on my first novel, to the detriment of pretty much all my other projects. But the first draft is now complete–ringing in at 158,000 words–and I now have the bandwidth to return to other creative endeavors…

…which brings me to an announcement I’ve been very excited to make!

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Is Dark Matter Real?

/ Emma / 6 Comments

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 question of whether dark matter could explain supermassive black holes.

What we have yet to do is take a proper deep dive into what the heck this stuff actually is. But there’s an even more important question…

How do we know it’s actually real?

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A Peek at Supermassive Black Holes

/ Emma / 11 Comments

There are few things in the universe quite as exciting as black holes.

They’re in all the movies–I even wrote a post a few years ago on what the movies get wrong about them! Though some movies, like Interstellar, do a pretty good job of capturing the relativistic effects.

There are also plenty of popular misconceptions floating about–probably thanks to those fictional portrayals!

Most of the time, when we geek out over black holes, we’re talking about stellar-mass black holes. That is, the remains of massive stars.

Wait a second…most of the time? What other kind of black hole could we be talking about?

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How Massive are Galaxies?

/ Emma / 3 Comments

If you needed to measure the mass of, say, a brick–or some other Earthly object–you could just set it on a scale. (Yes, scales measure mass, not weight.)

With galaxies, it’s not so easy! I don’t think anyone’s invented a scale big enough yet…

But if we can measure the mass of a galaxy, it brings us that much closer to understanding its origin. And that brings us closer to learning the story of the universe.

So…how do you measure a galaxy’s mass? And just how massive are they?

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Another Astrophotography Night!

/ Emma / 5 Comments

Last night, I headed out to my driveway again and set up my C11–but this time, I borrowed my dad’s camera!

I’m just starting out, and I haven’t done anything with these photos yet. I’ve installed Deep Sky Stacker for turning these into quality amateur photos, but I haven’t actually started using it yet. I also don’t have Photoshop (and can’t get it just yet…). My dad did touch these up just a bit on his computer, but there is very little editing going on at this point. And these are my first photos ever.

(These are credited to my other blog, risingstargazer.com, which is set to launch soon. Right now, you’ll just see a “Coming Soon” banner.)

But they came out surprisingly good, so I thought I’d share…

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