So! I’m working on a series of stories set on a tidally locked moon called Failaka, orbiting a “hot Jupiter” called Tylos around an even hotter star called Dilmun. I don’t know if anything like Failaka exists, but Tylos is a real planet originally designated WASP-121b, orbiting a star called, um, WASP-121, about 850 light years from Earth.
Dilmun is a yellow-white star hotter and brighter than our Sun (itself white, not yellow), and Tylos orbits so close its parent star that its orbit takes one and a quarter Earth days, cooking the planet to a sizzling 2500 degrees Kelvin (about four thousand degrees Fahrenheit). Failaka is a cometary remnant, and if it exists, it could only survive in the shadow of Tylos, which itself appears as a bright orange, hot as a hot coal.
SO, to make the story more grounded, I worked out where Failaka would have to be (Tylos’s L2 point, currently calcuated as about the distance from the Earth to the Moon), how relatively bright Tylos and Dilmun were, and how large Tylos and Dilmun would be in the sky, as well as their colors.
The above renders this in Mathematica. Tylos is the orange circle partially occluding the white disk of Dilmun behind it, and Failaka is the blue plain of ice below – ice which, if it really was this exposed to Tylos and Dilmun, would be rapidly sublimating away, as the plot demands that the planet “roll” due to an orbital shift, leading to plains of former darkside ice shifting into the light and rapidly disintegrating.
Oh, and the tiny dots to the right of Dilmun? The white dot is the Sun, in natural color. The next dot is the Moon, rendered in grey, as the moon’s albedo is actually kinda like charcoal.
And now, a helpful safety tip: do not stand on Failaka where you can see this view of Tylos and Dilmun. The radiation would be thousands of times as bright as the Sun seen from Earth, and you would rapidly have a very abbreviated day.
If you see this unprotected, you will die.
The good news? Cremation is free.
-the Centaur
