Astronomers have found a very interesting new exoplanet called TOI-5734 b that is about 106 light-years away from Earth. The Transiting Exoplanet Survey Satellite (TESS) and the HARPS-N spectrograph helped scientists find the planet. It gives us new information about the many different types of exoplanets in our galaxy. A study on arXiv from February 2026 talks about this discovery, which helps us learn more about planets that fall into the sub-Neptune category. TOI-5734 b has some very interesting features that give us important information about how planets change over time and what the weather is like on other worlds.
TOI-5734 B: A New Find in Exoplanet Research
Finding TOI-5734 b is a big step forward in the study of exoplanets, especially those that are sub-Neptunes. An international group of astronomers has discovered this hot, rocky planet orbiting a young star using data from TESS and the HARPS-N spectrograph. The exoplanet is in the constellation Lyra, about 106 light-years from Earth. It is a great example of how new technologies are letting us explore faraway worlds in more depth. According to the study on arXiv, TOI-5734 b is a giant planet because its radius is about twice that of Earth.
The planet goes around its star, TOI-5734, which is a relatively young K3-K4 dwarf star, every 6.18 days. TOI-5734 b is in the hot sub-Neptune category because it has a mass nine times that of Earth and a radius of 2.1 Earth radii. This category is known for having a gas-rich atmosphere and being very big. Simone Filomeno of the Astronomical Observatory of Rome, Italy, led the team that made the discovery. They used data from three TESS sectors and spectroscopic information from the HARPS-N spectrograph at the Galileo National Telescope. The astronomers said that
“In this paper, we talk about how we found and described the transiting young planetary system TOI-5734 (TIC 9989136).”
The Ordinary serum called filler in a bottle gives skin smoother youthful appearance in your 40s
New Hot Sub Neptune Ex
The TESS target pixel file for Sector 20 of TOI-5734, which is marked with a “1.” Credit: arXiv (2026). DOI: 10.48550/arxiv.2602.18108
The Star That Led to the Discovery: TOI-5734
TOI-5734 b’s host star, TOI-5734, is a young, cool dwarf star. TOI-5734 is much smaller than the Sun. It has a mass of about 0.72 solar masses and a radius of 0.64 solar radii. Astronomers can learn a lot from this star, even though it is smaller than other stars. They are trying to figure out how planets like TOI-5734 b form and change over time. TOI-5734’s effective temperature is about 4,750 K, which is normal for stars like it. In terms of the universe, this star is still pretty young, only a few billion years old.
The astronomers in the study said that they found TOI-5734 b by looking at TESS data from 2022, when they saw a transit signal in the light curve of this star. They said, “The study was done using data from three TESS sectors and the HARPS-N spectrograph at the TNG [Galileo National Telescope].” This mix of data sources helped the researchers prove that the planet exists and start to figure out what it is like.
What You Need to Know About TOI-5734 B: Its Size and Mass
TOI-5734 b is an interesting object to study further because of its size and mass. The exoplanet is considered a super-Earth or a sub-Neptune because it is about 2.1 Earth radii wide and 9.1 Earth masses heavy. It is a little less dense than Earth, which suggests that it may not be made up of only rock and metal. The planet is very close to its host star, only 0.06 AU away, and it takes only 6.18 days to go around it. This closeness is what makes it so hot, with an estimated equilibrium temperature of about 688 K.
TOI-5734 b is a great candidate for studying how planets behave in extreme conditions because of its size, mass, and close proximity to its star. The planet’s location in the “radius valley,” which is a gap in the size distribution of planets between 1.5 and 2.0 Earth radii, makes it even more valuable for science. The study says that TOI-5734 b is right on the upper edge of this radius valley, which astronomers have been interested in for a long time because it helps them learn about how exoplanets form and change over time.
The chemical makeup and future changes of TOI-5734 B
One of the most interesting things about TOI-5734 b is what its chemical makeup might be. The study indicates that the planet is probably rocky, but its atmosphere is being stripped away a lot. The scientists think that TOI-5734 b has almost lost its original atmosphere, but there is still a chance that it could be a water world. Because the planet is so hot and close to its star, it has probably lost lighter elements from its atmosphere over time. The astronomers think that TOI-5734 b will probably lose all of its original atmosphere in 300 million years.
The authors of the study go on to talk about how the planet has changed over time. They say that TOI-5734 b may have formed farther away from its host star and then moved closer over time. This is a common way for many exoplanets to move, especially those that are close to their star’s habitable zone. The fact that TOI-5734 b is now near the radius gap suggests that it has changed a lot over the course of its life.
