A planet named HD 63433 orbiting its star

Source : NASA

Earth-sized Planet Has a ‘Lava Hemisphere’

In a system with two planets we knew about, scientists noticed something different: a small object passing in front of a star similar to our Sun. Upon closer look, they realized it's not just anything; it's an additional planet, resembling Earth in size but with much higher temperatures.

The recently found planet, named HD 63433 d, is tidally locked, which means one side is always facing its star, and the other side remains in constant darkness. This exoplanet, a planet outside our solar system, revolves around the star HD 63433 (also known as TOI 1726) within the HD 63433 planetary system. This blazing world is the smallest confirmed exoplanet that's younger than 500 million years. It's also the nearest Earth-sized planet discovered at around 400 million years old. 🌌🚀

A group of space detectives, armed with NASA's TESS (the space telescope that's like a cosmic detective), were on the case! This star system already had two known planets, but our cosmic detectives wanted to see if there was anything else hiding in the star's neighborhood. So, they used TESS to study the starlight and removed the signals from the two known planets. Lo and behold, they spotted a sneaky signal - a little transit happening every 4.2 days. After some serious investigating, they confirmed it: a third, smaller planet was in the mix.
This tiny planet, locked in a cosmic dance, is almost Earth's size (just 1.1 times as big as our home planet). It's circling a star that's a Sun lookalike (almost the same size and just a smidge lighter). This star is of the same type as our Sun, called a G-type star. But here's the twist: HD 63433 d is way cozier with its star, completing its "year" in just 4.2 days and sizzling under some serious heat on its sunny side! ☀️🌍
This brand-new planet and its star may seem like our familiar Earth and Sun, but HD 63433 d is a whole different story.
First off, it's like the baby of the cosmic block. The entire system it's in is around 10 times younger than ours, and this little 400-million-year-old planet is just a cosmic toddler compared to our ancient 4.5-billion-year-old Earth.
But here's the kicker: HD 63433 d likes to cozy up way closer to its star than we do with the Sun. It's 8 times nearer to its star than Mercury is to the Sun. Being so close, the sunny side of this planet can get as hot as 2,294 Fahrenheit (1,257 Celsius). That's scorching! Because it's so tiny, young, and near its star, this planet probably doesn't have much of an atmosphere.
Think of it like a lava world, similar to planets like CoRoT-7 b and Kepler-10 b. The team that found it even thinks one side of the planet might be like a "lava hemisphere."
Its small size, youth, and close orbit make it a real head-turner for scientists. Future studies could confirm what we know and maybe spill the beans on its "dark side" and whether it's got any air to breathe. As the scientists put it, "Young planets like this are super important for testing our ideas about how planets form and grow."