Latest news with #redDwarf
Emirates 24/7
4 days ago
- Science
- Emirates 24/7
NASA discovers 'super Earth' planet emitting mysterious signal
NASA has discovered a mysterious 'super-Earth' planet that appears to flash a repeated signal from 154 light-years away. The planet, named TOI-1846 b, is almost twice the size of Earth and four times as massive. It orbits a small, cool red dwarf star every four days and causes a strange, repeated dip in the star's light, a signal that first caught scientists' attention when NASA's TESS space telescope observed the dimming pattern in March of each year. Now confirmed by a team of scientists using both space and ground-based telescopes, TOI-1846 b falls into the so-called 'radius gap,' a rare category between small, rocky planets like Earth and larger, gas-rich planets like Neptune. Despite an estimated surface temperature of 600°F, researchers say the planet may still hold water. It's believed to have a solid rocky core, a dense ice layer, and potentially even a shallow ocean or thin atmosphere. The host star is a "red dwarf," approximately 40 percent smaller in size and mass than the Sun. NASA scientists hope that the James Webb Space Telescope will soon target TOI-1846 b to study its atmosphere using infrared light. Under favourable conditions, Webb will be able to detect signs of water vapour, methane, carbon dioxide, or other gases. Follow Emirates 24|7 on Google News.
Daily Mail
5 days ago
- Science
- Daily Mail
NASA discovers 'super Earth' planet sending mysterious signal
NASA has discovered a mysterious 'super-Earth' planet that appears to flash a repeated signal from 154 light-years away. The planet, named TOI-1846 b, is almost twice the size of Earth and four times as massive. It orbits a small, cool red dwarf star every four days and causes a strange, repeated dip in the star's light, a signal that first caught scientists' attention when NASA's TESS space telescope observed the dimming pattern in March of each year. Now confirmed by a team of scientists using both space and ground-based telescopes, TOI-1846 b falls into the so-called 'radius gap,' a rare category between small, rocky planets like Earth and larger, gas-rich planets like Neptune. Despite an estimated surface temperature of 600°F, researchers say the planet may still hold water. It's believed to have a solid rocky core, a dense ice layer, and potentially even a shallow ocean or thin atmosphere. Abderahmane Soubkiou, lead researcher at Oukaimeden Observatory in Morocco, said: 'We have validated TOI-1846 b using TESS and multicolor ground-based photometric data, high-resolution imaging, and spectroscopic observations.' Their measurements also showed that the planet circles its star in just under four days, staying on an orbit that is much closer to its sun than Mercury in our Solar System. The host star is a red dwarf, about 40 percent the size and mass of our sun, glowing at around 6,000°F. Because red dwarfs are smaller and dimmer, planets must orbit close to receive warmth, which also makes it easier for telescopes to detect them as they pass in front of the star. TESS, which launched in 2018, has flagged more than 7,600 such transit events and confirmed over 630 planets so far. Its four high-sensitivity cameras scan the sky every 30 minutes, making it ideal for spotting shallow light dips like those from TOI-1846 b. The newly discovered planet is also likely tidally locked, meaning one side always faces its star while the other remains in darkness. This temperature contrast could allow water to be trapped in cooler regions, depending on how heat moves through the atmosphere. NASA scientists hope the James Webb Space Telescope will soon target TOI-1846 b to study its atmosphere using infrared light. If conditions are right, Webb could detect signs of water vapor, methane, carbon dioxide, or other gases. Ground-based telescopes like the Gemini Observatory in Hawaii are also contributing, using a precision instrument called MAROON-X to measure the tiny wobble in the star caused by the planet's gravitational pull, helping confirm its mass and look for hidden neighbors. Researchers believe TOI-1846 b might not be alone. Subtle shifts in its orbit suggest another planet could be lurking in the same system, potentially one orbiting farther out in a cooler, more habitable zone. The discovery comes alongside another recent find: TOI-715 b, a second super-Earth located 137 light-years away, also orbiting a red dwarf. Both planets help fill key gaps in astronomers' understanding of how some small planets lose their atmospheres over time while others manage to keep them. As red dwarfs make up about 75 percent of all stars in the Milky Way, studying planets like TOI-1846 b could reveal how many more potentially habitable worlds might be hiding in our galactic backyard. These discoveries mark another step forward in humanity's quest to understand the makeup of exoplanets and the potential for life beyond Earth. With continued support from both space- and ground-based observatories, astronomers hope to uncover even more secrets locked within the atmospheres and orbits of these distant worlds.
WIRED
09-07-2025
- Science
- WIRED
A Giant Planet and a Small Star Are Shaking Up Conventional Cosmological Theory
Jul 9, 2025 7:00 AM A gas giant comparable in size to Saturn has been found orbiting a small red dwarf star. The discovery is making experts reconsider conventional notions of how planets form. An illustration of the giant gas planet TOI-6894b orbiting the small, dim red dwarf star TOI-6894. Illustration: University of Warwick/Mark Garlick Many of the stars in the Milky Way galaxy are small, dim red dwarfs—stars much smaller than the sun in both size and mass. TOI-6894, located far away from Earth, is one of them. Astronomers previously thought a star like this could not have large planets circulating it, because its mass is only about 20 percent of the sun, meaning its planetary system—generated from materials surrounding the star—would not have contained enough mass to form a giant body like Saturn or Jupiter. But when observing TOI-6894, an international research team detected a clear transit signal—a temporary decrease in a star's brightness caused by a planet passing across it. This newly discovered planet, named TOI-6894b, blocks 17 percent of the star's light, indicating the planet is fairly large. The signal was picked up by the Transiting Exoplanet Survey Satellite (TESS), an observation instrument launched by NASA to hunt for planets orbiting stars outside of our solar system. This makes TOI-6894 'the lowest mass star known to date to host such a planet,' said Edward Bryant, Astrophysics Prize Fellow at the University of Warwick, in a press statement. The finding appears to upend conventional theory on how planets are formed. 'This discovery will be a cornerstone for understanding the extremes of giant planet formation,' Bryant said. Astronomers at University College London and the University of Warwick, as part of a global collaboration with partners in Chile, the US, and Europe, trawled through the data of about 91,000 red dwarf stars observed by TESS before discovering the planet TOI-6894b. After that, the nature of TOI-6894b was clarified by additional observations made with other telescopes. According to these, TOI-6894b's radius is slightly larger than Saturn's, but its mass is only about half that of the ringed giant. Its density is extremely light at only 0.33 g/cm³, indicating that it is an expanding gas planet. TOI-6894 is nearly 40 percent smaller than the previous record for the smallest star with a planet of this size. This fact poses a serious contradiction to conventional theories of planet formation. The widely accepted planetary formation model, the 'core-accumulation theory,' proposes that a ring of dust and rocks—known as protoplanetary disk—forms around a star, and that materials in this disk then gather together to form the cores of planets. After starting out this way, larger gas planets then accrete gases around their cores to become gigantic. But if the mass of the star is small, the mass of its protoplanetary disk tends to be small as well. In such a scenario, the nucleus necessary for the formation of a giant gas planet will not grow. Based on this theory, it is estimated that more than 120 times more solid matter than that of the Earth would be required to form TOI-6894b. However, the observed disk surrounding the star TOI-6894 contains only 58 times the mass of the Earth at most. This raises the possibility of an alternative planet-formation mechanism existing. One suggestion by Bryant and the team is that planets could form by gradual gas accumulation, without the initial formation of a massive core. 'Alternatively, it could have formed because of a gravitationally unstable disc,' Bryant says. 'In some cases, the disc surrounding the star will become unstable due to the gravitational force it exerts on itself. These discs can then fragment, with the gas and dust collapsing to form a planet.' However, the press statement goes on to explain that neither of these theories can could completely explain the formation of TOI-6894b, based on the data gathered. For now the planet's origin remains a mystery. Analyzing the atmosphere of the newly discovered exoplanet might yield answers; it is possible that chemical traces of its formation process remain. Observations of TOI-6894b by the James Webb Space Telescope over the next 12 months are expected to reveal details about its interior structure and atmospheric composition, which will have a major say on whether current theories about planet formation are supported or new ones are needed. The discovery may force us to rethink our unified model of planet formation, says Andrés Jordán of the Millennium Astrophysics Institute at Adolfo Ibáñez University in Chile. Years of steady observations are pushing the limits of theory, and it may even be time to fundamentally rethink our estimates of the total number of giant planets in the galaxy. This story originally appeared on WIRED Japan and has been translated from Japanese.
