The floodgates are open. Scientists have announced the first exoplanet discovered by NASA’s TESS telescope, launched in April 2018, with thousands more expected to be discovered in the coming years.
This planet is called Pi Mensae c, and it's described in a paper on the preprint server arXiv. It still needs to be confirmed that the planet definitely exists, with the paper currently under peer review, but the team say they are confident in their discovery.
“It was extremely exciting for the team!” Natalia Guerrero from the Massachusetts Institute of Technology, a member of the TESS team and a co-author on the paper, told IFLScience. “Pi Mensae c is exactly the type of planet TESS was designed to find – a small planet around a bright nearby star.”
The planet discovered by TESS, a successor to NASA's wildly successful Kepler space telescope, is not “small” compared to our own, but it is small compared to the abundance of gas giants TESS is expected to find. Pi Mensae c is about 2.1 times the size of Earth, and completes an orbit of its star in 6.27 days. The star it orbits, a yellow dwarf, is located about 60 light-years from Earth.
Pi Mensae c is thought to be a super-Earth, a large and potentially terrestrial planet with a rocky core. Being so close to its star, it’s unlikely to have water or be habitable due to its high temperature. The mass of the planet is estimated to be about 4.8 times that of Earth.
It’s actually the second planet we know of in this system, the other being Pi Mensae b discovered in 2001, a planet 10 times the mass of Jupiter that orbits in 5.7 years. That in itself raises questions about how these two very different planets came to evolve in this system.