A new Earth-sized planet was discovered that will orbit a star and live for 100 billion years

Researchers using global robotic telescopes discovered an Earth-sized planet, Speculos-3b, orbiting an extremely cold red dwarf. GalaxyThe planet is tidally locked and lacks an atmosphere because of its intense radiation, and provides new insights into long-lived red dwarfs, which are predicted to be among the last stars in the universe to burn out.

Our galaxy is a treasure trove of red stars. In fact, more than 70% of the stars in the Milky Way are M dwarfs, also known as red dwarfs. These stars are cooler and dimmer than our Sun, but they often destroy orbiting exoplanets with high-energy radiation early in their lives. And their “lives” last much longer tall Time. Stars like our Sun burn for about 10 billion years, after which they turn into hungry red giants that gobble up any nearby planets. M dwarfs burn for 100 billion years or more, perhaps providing a basis for life to form, and an even longer time for life to evolve.

An international team using robotic telescopes around the world recently spotted an Earth-sized planet orbiting an extremely cool red dwarf star, the dimmest and longest-lived star known. These will be the last stars to burn out when the universe becomes cold and dark.

Search

exoplanets Speculos-3b is about 55 light years away from Earth (actually much closer when considering the cosmic scale!) and is about the same size. A year there, one orbit around the star, takes about 17 hours. However, day and night could never end: the planet is thought to be tidally locked, so the same side, called the day side, always faces the star, like the Moon for Earth. The night side would be locked in never-ending darkness.

An artist’s concept of the exoplanet Speculos-3b orbiting its red dwarf star. The planet is about as big as Earth, while its star is slightly larger than Jupiter – but much more massive. Credit: Leonel Garcia

Discovery of ultra-cool dwarfs

In our corner of the galaxy, ultra-cool dwarf stars are ubiquitous. They are so faint that their planetary constellations have largely gone undetected. The SPECULOOS (Search for Planets eclipsing ultra-cool stars) project, led by Michael Gillon at the University of Liège in Belgium, was designed to change that. Ultra-cool dwarf stars are scattered across the sky, so you have to observe them one by one, for weeks, to have a good chance of detecting transiting planets. For that, you need a dedicated network of professional telescopes. That’s the concept of SPECULOOS.

“We designed Speculos specifically to explore nearby ultra-cool dwarf stars in search of rocky planets,” said Gillon. “With the significant help of the Speculos prototype and the team at NASA Together with the Spitzer Space Telescope, we discovered the famous TRAPPIST-1 system. It was a great start!”

Gillon is the lead author of the paper announcing the planet’s discovery, published on May 15, 2024. Nature AstronomyThe project is a truly international effort, with partnerships with the Universities of Cambridge, Birmingham, Bern, Massachusetts Institute of Technology and ETH Zurich.

The Speculos-3 star is thousands of degrees cooler than our sun, with an average temperature of about 4,760 F (2,627 C), but it bombards its planet with radiation, meaning it probably has no atmosphere.

Just observing the star, let alone the planet, is an accomplishment in itself. “Although this particular red dwarf star is thousands of times dimmer than the sun, its planet orbits much closer than Earth, causing the planet’s surface to heat up,” said co-author Katherine Clark, a postdoctoral researcher at NASA’s Jet Propulsion Laboratory in Southern California.

Fun facts

• Although the planet is as large as Earth, its star is only slightly larger than Earth. Jupiter – But much more spacious.
• The Earth receives about 16 times more energy from the Sun per second than the Earth receives from the Sun.
• Do you get the cookie connection? The planet-finding program SPECULOOS gets its name from a spiced shortbread. Both are from Belgium. Sweet!

Next Steps

Speculos-3b is an excellent candidate for follow-up observations by the James Webb Space Telescope. Not only can this tell us about the possibility of an atmosphere and the mineralogy of the surface, but it can also help us understand the stellar neighborhood and our place in it.

“We are making great strides in studying planets orbiting other stars,” said Steve B. Howell, one of the planetary discoverers at NASA Ames Research Center in Silicon Valley. “We have now reached a stage where we can detect Earth-sized planets and study them in detail. The next step will be to determine whether any of them are habitable or if anyone lives there.”

For more information about this discovery:

Reference: “Detection of an Earth-sized exoplanet orbiting the nearby ultracool dwarf star Speculos-3” by Michael Gillan, Peter P. Pedersen, Benjamin V. Rackham, Georgina Dransfield, Elsa Ducrot, Khalid Barkaoui, Artem Y. Burdanov, Urs Schröffenger, Yilen Gómez Mak Chew, Susan M. Lederer, King Alonso, Adam J. Burgasser, Steve B. Howell, Norio Narita, Julien de Wit, Brice-Olivier Demory, Didier Queloz, Amaury H.M.J. Triad, Laetitia Delrez, Emmanuelle Jehin, Matthew J. Hooton, Lionel J. Garcia, Claudia Jano Muñoz, Catriona A. Murray, Francisco J. Pozuelos, Daniel Sebastian, Mathilde Timmermans, Samantha J. Thompson, Sebastian Zuniga-Fernandez, Jesus Oliva, Christian Aganze, Pedro J. Love, Thomas Bycroft, Zouhair Benkhaldoun, David Berardo, Emlyn Bolmont, Catherine A. Clarke, Yasmine T. Davis, Fatemeh Davoudi, Zoe L. de Beers, Jerome P. de Leon, Masahiro Ikoma, Kai Ikuta, Keisuke Isogai, Izuru Fukuda, Akihiko Fukui, Roman Gerasimov, Mourad Ghachaoui, Maximilian N. Günther, Samantha Hassler, Yuya Hayashi, Kevin Heng, Renyu Hu, Taki Kagetani, Yugo Kawai, Kiyo Kawauchi, Daniel Kitzman, Daniel D. B. Cole, Monica Lendl, John H. Livingston, Xintong Lyu, Eric A. Meyer Valdes, Mayuko Mori, James J. McCormack, Philippe Murgas, Prajwal Niroula, Enrique Paley, Ilse Plauchau-Freyne, Rafael Rebollo, Laurence Sabin, Yannick Shacky, Nicole Schanche, Frank Celsis, Alfredo Sota, Manu Stalport, Matthew R. Standing, Kevan G. Stassen, Motohide Tamura, Yuka Terada, Christopher A. Theisen, Martin Turbet, Valerie Van Grootel, Roberto Varas, Noriharu Watanabe, and Francis Zong Lang, May 15, Nature Astronomy,
DOI: 10.1038/s41550-024-02271-2