Daytime temperatures on the planet can reach 2,700 degrees Celsius, or 3,000K, and its nightside temperature of 2,300C is the second hottest ever measured.

Researchers at the University of Southern Queensland’s Centre for Astrophysics in Toowoomba led the global team that made the discovery.

Astrophysicist Dr Brett Addison described it as “a hellish world”. “No life would be able to survive in its atmosphere,” he said.

“This planet is a gas giant planet so it doesn’t really have a solid surface like the terrestrial planets in the solar system.

Global effort

NASA’s Training Exoplanet Survey Satellite first flagged TOI-1431b as a possible planet in late 2019.

Dr Addison said follow-up observations collected over several months with a Stellar Observation Network Group telescope in the Canary Islands — along with other telescopes around the world — helped him confirm the planet’s existence.

“I could see the radio velocity orbits starting to become quite clear, showing the star wobbling back and forth,” he said.

“At that moment I knew, okay this is definitely a planet. It’s a massive planet.

The planet – outside our solar system – is roughly one-and-a-half times the size of Jupiter and orbits around a very hot star approximately every two days.

It has a retrograde orbit, meaning it travels in the opposite direction to the rotation of its host star.

TOI-1431b is also known by researchers as MASCARA-5b, but Dr Addison said it had nothing to do with makeup. “That stands for Multi-site All Sky Camera,” he said. “That name is based on the survey [that found the planet]. “Astronomers like to come up with cute acronyms for their telescopes and observatories.”

One piece of the puzzle

Humans won’t be setting foot on TOI-1431b anytime soon — or more likely ever. Aside from the unbearable temperatures, its gas composition means it lacks a defined surface.

But Dr Addison said it was still a critical discovery as it would contribute to the global space community’s understanding of planet formation and migration.

Professor of planetary astrophysics at the University of California, Stephen Kane, said the research helped to place the solar system “in context”.

“These kinds of discoveries teach us a lot about the diversity of planetary systems and what kind of architectures can exist,” he said.

“In order to have this giant planet close to its star then it must have moved.

“Finding more of these kinds of planets will give us more data with which to study these kinds of phenomena and try to understand better how this kind of migration occurs.”

According to