ISAT Two Hats emotionally destroyed me, so have a Loop playlist:
(Spoilers for all of In Stars and Time, including the Two Hats ending):
Playlist Image Credit: NASA / ESA / G. Bacon (STScI)
Explanation of image/astronomy metaphor under the cut:
The image shows the binary star system (two stars that orbit each other) Sirius A and Sirius B. Sirius is one of the most well known stars (colloquially known as the Dog Star) as it is the brightest in the night sky, while Sirius B is 10,000 times dimmer than Sirius A but is still detectable via telescope and through its gravitational attraction to Sirius A.
Sirius A is what's known as a main sequence star, a star that is still fusing hydrogen into helium and is considered "alive". Sirius B is a white dwarf, a star that no longer produces fusion. It's at the end of the star life cycle, a "dead" star.
Sirius B was initially more massive than Sirius but used up its fuel, expanding into a red giant as the layers were blown apart, before eventually collapsing into a white dwarf. None the less, they remain gravitationally bound to one another in a binary system.
Fun fact: the material ejected from red giants often helps form new stars!
