Madison G. Scott; Georgina Dransfield; Mathilde Timmermans; Amaury H. M. J. Triaud; Benjamin V. Rackham; Khalid Barkaoui; Adam J. Burgasser; Karen A. Collins; Michaël Gillon; Steve B. Howell; Alan M. Levine; Francisco J. Pozuelos; Keivan G. Stassun; Carl Ziegler; Yilen Gomez Maqueo Chew; Catherine A. Clark; Yasmin Davis; Fatemeh Davoudi; Tansu Daylan; Brice-Olivier Demory; Dax Feliz; Akihiko Fukui; Maximilian N. Günther; Emmanuël Jehin; Florian Lienhard; Andrew W. Mann; Clàudia Janó Muñoz; Norio Narita; Peter P. Pedersen; Richard P. Schwarz; Avi Shporer; Abderahmane Soubkiou; Sebastián Zúñiga-Fernández (2026)..Monthly Notices of the Royal Astronomical Society, 547(1), stag070.
As scientists discover more types of exoplanets (planets outside our solar system), they are rethinking what conditions might allow a planet to be habitable. Traditionally, the “habitable zone” is defined as the range of distances from a star where liquid water could exist on a planet’s surface. In this study, the authors propose a broader concept called the“temperate zone,”defined by the amount of stellar energy a planet receives (instellation), specifically between 0.1 and 5 times the amount Earth gets from the Sun. This wider range includes more planets that might potentially support life under different conditions.
The researchers also introduce the TEMPOS survey, which focuses on measuring the sizes of planets orbiting very cool, small stars known as M dwarfs. As part of this effort, they discovered and confirmed two planets: TOI-6716 b and TOI-7384 b. TOI-6716 b is about the same size as Earth, while TOI-7384 b is larger (closer to a “mini-Neptune”). Both orbit relatively cool M dwarf stars and complete an orbit in just a few days. The team used multiple methods—including ground-based observations, high-resolution imaging, and statistical validation—to confirm these planets and precisely measure their sizes.
Both planets receive relatively high levels of stellar energy, placing them near the hotter inner edge of the proposed temperate zone. This means they may be too warm for Earth-like conditions, but they are still valuable for studying planetary environments. Notably, TOI-6716 b could be a promising target for the James Webb Space Telescope, especially fortransmission spectroscopy(a technique that analyzes starlight passing through a planet’s atmosphere to detect its composition), if it has retained an atmosphere. Overall, this work expands the range of planets considered potentially interesting for habitability studies and contributes new targets for future observation.
Figure 1.
