SEA: Space Exploration & Astronomy

Not every star in the universe can be seen shining brightly in the night sky. There are dozens of types of fascinating hypothetical stars, which are characterised by their extreme behaviour. Today, we will be taking a look at a few of these corrupted stars, from the start of the universe right up until the end.

MUSIC TRACKS:
- Passing a Foreign Moon - I Think I Can Help You (YouTube Audio Library)
- The Shadow Self - I Think I Can Help You (YouTube Audio Library)
- The Bardo - I Think I Can Help You (YouTube Audio Library)
- To Have To In Least Water - pATCHES (YouTube Audio Library)
- Surviving the Asteroid Belt - I Think I Can Help You (YouTube Audio Library)
- Wander - Emmit Fenn (YouTube Audio Library)
- Because for Everything There Is Someone - pATCHES (YouTube Audio Library)
- Adrift - ELPHNT (YouTube Audio Library)
- Verve - Benjamin Martins (YouTube Audio Library)
- Hollows - Houses of Heavens (YouTube Audio Library)
- Meeting Again - Emily A Sprague (YouTube Audio Library)
CHAPTERS:
00:00: Introduction
01:29: Population III Stars
04:50: Quasi Stars
07:42: Thorne-Zytkow Objects
10:37: Q-Stars and Exotic Matter
14:02: Quark Stars
15:51: Electroweak Stars
17:39: Strange Matter and Strange Stars
20:13: White Dwarfs
21:54: Frozen Stars
22:37: Black Dwarfs
23:18: Iron Stars

Not every galaxy is a fully formed spiral or elliptical galaxy. Some are much smaller, and orbit larger galaxies as well as each other, like ghosts. Today, we will examine these ghost galaxies- the satellites of the Milky Way and Andromeda.

SOUNDTRACK:
- The Sun is Scheduled to Come Out Tomorrow - Chris Zabriskie
- Cylinder Four - Chris Zabriskie
- I Can't Imagine Where I'd Be Without It - Chris Zabriskie
- Cylinder Two - Chris Zabriskie

All tracks by Chris Zabriskie licensed under a Creative Commons Attribution license
(https://creativecommons.org/licenses/by/4.0/)
Artist: http://chriszabriskie.com/

00:00: Antlia 2: A Ghost Galaxy
02:16: Dwarf Galaxies 
06:14: Types of Dwarf Galaxy
08:00: Case Studies 
09:14: Magellanic Clouds 
12:35: The Triangulum Galaxy

Supervoids are the enormous, empty spaces between galaxy clusters and galaxy filaments. But just because they are empty, doesn't mean they can't be filled with fascinating science! They have taught us a great deal about both galaxy structures in the early universe, and how they grow in the present. And today we'll be venturing into a few of the biggest!

MUSIC:
- Long Walks [Emily A Sprague] - YouTube Audio Library
- Fairy Meeting [Emily A Sprague] - YouTube Audio Library
- A Slow Dream [Emily A Sprague] - YouTube Audio Library
- Devoid [ELPHNT] - YouTube Audio Library
- Rain Cloud Music [Emily A Sprague] - YouTube Audio Library

CHAPTERS:
00:00: Emptiness in Space
02:04: Defining a Void
03:52: Mapping Voids Around Us
04:38: How Voids Form
07:05: The Bootes Void
09:16: Voids and Dark Energy
10:33: The Cold Spot
12:10: The KBC Void

Quasars are the brightest phenomenon in the entire universe, able to outshine any type of star, and even entire galaxies containing hundreds of billions of them. They are the product of monster black holes at the centres of large galaxies, and so when we find multi-billion light year clusters of quasars dotted around the early universe, we are forced to reconsider some of our most fundamental assumptions of cosmology.

BACKGROUND MUSIC:
- Cylinder One - Chris Zabriskie
- Descent - The Tower of Light (YT Audio Library)
- Dreaming Blue - Sextile (YT Audio Library)
- Turn - The Tower of Light (YT Audio Library)
- There Are Many Different Kinds of Love - Chris Zabriskie
- Retro Dreamscape - Twin Musicom (YT Audio Library)
- Flecks of Light - The Tower of Light (YT Audio Library)
- Clouded - Public Memory (YT Audio Library)
- Trickling Up - Godmode (YT Audio Library)

Songs by Chris Zabriskie are licensed under Creative Commons 4.0 Licence:
- Artist: http://chriszabriskie.com/
- Source: http://chriszabriskie.com/cylinders/

00:00: Introduction
02:00: What is a Quasar?
09:46: The Peak Quasar Epoch
11:50: The Search for Quasars
20:39: Large Quasar Groups
22:15: Cosmic Structures & the Cosmological Principle
24:35: The Largest LQGs
27:34: Seeing Patterns In Noise

Stars come in a wide range of sizes, but how do we calculate a star's size to determine which is the largest? In this episode, we will find out how stars are measured to determine their mind-boggling sizes, and above all, which of them are the biggest of all.
PLEASE NOTE: This one is an older video of mine, back in 2021 when it was thought that the largest known star was Stephenson 2-18. It has since been reassessed as most likely not a member of the Stephenson-2 Cluster, and thus not amongst the candidates for the largest star. I plan to remake this video some time in 2026.

SOUNDTRACK:
Two songs in this video were made by Chris Zabriskie. (http://chriszabriskie.com/)
- Abandon Babylon (Album from which the songs came: https://chriszabriskie.bandcamp.com/album/abandon-babylon)Dark Fog & Ice Demon by Kevin MacLeod are both licensed under a Creative Commons Attribution 4.0 licence.
Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1300031 , http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1200061
Artist: http://incompetech.com/
All other music provided by the YouTube Audio Library
CHAPTERS:
00:00: Introduction
01:04: What Are Stars?
05:40: How Stars Get Big
09:38: Problems with Direct Measurements
11:31: Parallax
13:01: Indirectly Measuring Stars
15:33: VY Canis Majoris
18:30: UY Scuti
22:59: Stephenson 2-18