UFRN astronomers participate in the discovery of new exoplanet with NASA system. Exoplanets are planets that are outside the solar system. This is the second one discovered by UFRN scientists, who had already participated in the revelation of another one in 2019.
Researchers at UFRN discovered the exoplanet. Researchers from the Federal University of Rio Grande do Norte (UFRN) participated in learning a new exoplanet. The planet TOI-257b (HD 19916) is a hot sub-Saturn type with an orbital period of approximately 18 days.
The Structure made the discovery, Stellar Evolution and Exoplanets Group of the Theoretical and Experimental Physics Department.
“This is an important discovery for our group at UFRN, because, in two years, we are announcing the second exoplanet with our participation”, said the astronomer José Dias Nascimento Júnior, who participated in the discovery. He studies the evolution of stars and their structures.

“TOI-257b is an example of what astronomers call ‘sub-Saturns’, which are planets larger than Neptune and smaller than Saturn. It is a type of planet absent in the solar system, although possible.”
Planets outside the solar system are called exoplanets and are therefore in the orbit of other stars.
This is the second exoplanet discovered with the group’s participation and using data from NASA’s planet-hunting satellite, the TESS (Transiting Exoplanet Survey Satellite).
In 2019, the group announced the exoplanet of the type “Hot Saturn” TOI 197b with an orbital period of 14 days and discovered with the NASA telescope’s help.
New exoplanet
The planet TOI-257b is about 250 light-years away and completes an orbit around its star every 18 days. The researchers believe that it may be a gaseous world due to its low density.
The new exoplanet mass is forty times greater than that of Earth, and the volume is almost 350 times greater.
The researchers made space and ground observations, those made with the Minerva-Australis Observatory, a set of five robotic telescopes opening 70 centimetres at Mount Kent Observatory, operated by the University of Southern Queensland (USQ). The observatory was an essential support for NASA’s TESS observations.
Doctoral student Leandro de Almeida participated in the discovery of the 2019 exoplanet and the most recent. He explains that the finding is from a rare exoplanet (the size between Neptune and Saturn).
According to the researcher, with the work it was possible to characterize the host accurately and using stellar seismology. “This places this system among the few that have a very precise characterization.” he commented.

José Dias do Nascimento cites lessons learned from exoplanets and states that the universe is a peculiar and diverse place, with many types of planets. “There are sub-Saturns, super-earths and mini Neptunes. These planets do not exist in our yard, the solar system ”, he reinforces.
The UFRN researcher adds that the data still shows strong evidence of another planet in the system, the TOI-257c, which they hope to confirm between 2021 and 2022.
NASA System
In January, the TESS mission delivered a total of 1,604 planetary candidates and follow-up observations that resulted in a total of 37 confirmed planetary discoveries.
The UFRN group is currently the only Brazilian team directly involved in the discovery of exoplanets with TESS.