We asked iREx’s young astronomers: What’s your favourite planet?

Clémence: It’s not one, but four exoplanets around the star HR 8799. I love this system because it’s the first (and still one of the only!) examples of a star with multiple planets that we can directly photograph (the direct imaging method), which is very rare. And after years of observation, we can even see the planets orbiting the central star, which I find fascinating!

Thomas: Two of my favorite planets are undoubtedly the two giant planets around the star Beta Pictoris. The debris disk around this star has been studied since the 1980s. A first planet about 10 times the mass of Jupiter was detected through direct imaging in 2010, and a second one in 2019. It’s the first system I studied after joining iREx, and it continues to interest me today!

Simon D.: I quite like 55 Cancri e. It’s a rocky (and perhaps even lava) planet very close to its star. It’s a real puzzle in our field because the observations we have are very surprising, and we have difficulty explaining them with our current theories.

Marylou: The exoplanets that fascinate me the most right now are those in the habitable zone of the TRAPPIST-1 planetary system, because I can’t wait to see if the James Webb Space Telescope will detect an atmosphere on these exoplanets. The system includes seven Earth-sized planets, at least three of which are in the temperate zone of their very small star.

Lisa: Lava planets like K2-141 b, 55 Cancri e, and GJ367 b are my favorites! They experience extreme heat, and as they’re literally being roasted by their host stars, they’re covered in oceans of lava that contain unprecedented information about the interior of rocky planets!

Alexandrine: My favorite planet is Earth. I find it truly extraordinary that all the conditions have come together to allow the emergence and evolution of life. It’s thanks to Earth that we can now turn our gaze to space and study the other worlds out there!

Loïc: My favorite planets are the four large gas giant planets orbiting the young star HR 8799. This is the first multi-planet system that has been observed, and the planets are visible directly as bright points. We can even see them follow their orbits over the years! It’s helpful to know they were discovered by a Canadian team.

Vigneshwaran: My favorite exoplanet (so far!) is GJ 9827 d. This super-Earth is less dense, and exciting chemical processes could (?!) occur in its atmosphere. If only we could study it better!

Jared: My favorite exoplanet is the hot Jupiter WASP-121 b, mainly because I will be analyzing it using data from the James Webb Space Telescope. WASP-121 b belongs to a subcategory of hot Jupiters called ultra-hot Jupiters (because scientists are very inspired when it comes to inventing names). The temperature on the side of the planet that always faces the star (its “day” side) is so high that molecules break apart, but the temperature on the other side is low enough for the molecules to reform.

Giang: My favorite planet is K2-141 b. It’s the first lava planet I got to know. After working on it for so long, I’ve become attached to it!

Keavin: My favorite planet is Earth: it’s the only planet we know of with fantastic music. My favorite exoplanet is Proxima Centauri b. It’s one of the closest exoplanets to us, orbiting in the habitable zone of its host red dwarf star, making it an ideal candidate for the research I conduct on Earth-like exoplanets.

Charles-Édouard: Without a doubt, it’s K2-141 b! I’ve been studying the dynamics of lava planets since my Ph.D. Until recently, I only studied rocky planets in our Solar System as they were during their formation. It’s believed they were completely covered in lava back then! I struggled to convince my friends that studying the dynamics of planets from 4 billion years ago was interesting. Imagine my joy when I first heard about K2-141 b, a rocky exoplanet that now has an ocean of magma!