Once upon a time, in the vast and magical realm of stars, astronomers stumbled upon a truly peculiar and hilarious discovery! They found a star, known as a white dwarf, that was like no other they had ever seen before.

This star was a real prankster, having two completely different faces! One side was made of hydrogen, while the other side was all helium! Can you imagine how funny and surprising that must be?

Janus: Star Jester

• Astronomers are clever people who study the stars and planets in the night sky. They found this extraordinary star called a white dwarf. White dwarfs are like the remnants of old stars that once shone brightly, like our own sun. But as they grew older, they became red giants and then transformed into white dwarfs.
• The funny white dwarf with two faces, which they named Janus after a two-faced god, was spotted by a special telescope called the Zwicky Transient Facility (ZTF). The astronomers were amazed because it changed its brightness very quickly, like playing a cosmic game of peek-a-boo!
• To learn more about this cosmic jester, the astronomers used special tools, like the CHIMERA instrument and HiPERCAM, to look closely at Janus. Then they called upon the mighty W. M. Keck Observatory to give them even more information. With its help, they saw that one side of Janus was full of hydrogen, while the other side had only helium.
• Now, why on earth would a star have such different faces? The astronomers scratched their heads and came up with some amusing ideas! Maybe Janus was just going through a silly phase of being a white dwarf. You know, like how kids grow and change over time. Perhaps some white dwarfs, just like some kids, go from being “hydrogen” to “helium” on their surfaces.
• Another possibility they thought about was that sneaky magnetic fields might be playing tricks on Janus. These magnetic fields are like invisible forces around stars, and they might be stronger on one side of Janus, preventing the materials from mixing properly. That’s why one side has more hydrogen and the other side has more helium. It’s like Janus is wearing a magnetic hat, making it look different on each side!
• So, little stargazers, the astronomers were totally blown away by this hilarious two-faced star, Janus! It’s like a cosmic comedian, keeping them puzzled and entertained. They have some ideas about why it has two faces, but the star’s secret is still a big cosmic joke waiting to be fully understood.
• But fear not, for the astronomers won’t give up! They will keep using their magical telescopes to find more stars like Janus and learn even more about these cosmic clowns. Who knows, maybe someday, you too will become an astronomer and discover some funny, quirky stars of your own!
• And that, my dear young astronomers, is the tale of the two-faced white dwarf, Janus, who made everyone giggle and wonder in the vast playground of the universe! The end!