External worlds: An Earth-sized planet near a small star
SPECULOOS-3b is the name of an Earth-sized world orbiting a low-mass red dwarf at a short distance. However, it is too hot to support life like Earth.
SPECULOOS-3b is the name of an Earth-sized world orbiting a low-mass red dwarf at a short distance.
Under supervision Astronomer Michael Gillon A research team from the University of Liège has discovered an Earth-like exoplanet around a cool dwarf star in our cosmic neighborhood and reports on it in Nature Astronomy Journal. With a surface temperature of 2,600°C, the SPECULOOS-3 star is much cooler than the Sun at 5,500°C. It is also much smaller, with only about 10% of its mass and shines with only 0.08% of its luminosity. The system surrounding SPECULOOS-3 is only the second after TRAPPIST-1 in which planets have been observed passing around such a cool star. Although red dwarfs of this type make up by far the largest proportion of stars in the universe, their properties and those of their planetary companions are still poorly understood. Their low brightness makes detection and inspection difficult.
SPECULOOS-3 and its companion are located just 55 light-years from Earth in the constellation Persia. From an astronomical perspective, this puts them in the immediate vicinity of the solar system. The diameter of the exoplanet that was discovered is about 12,500 kilometers, which is slightly smaller than Earth. Due to its small distance from the central star, which does not exceed 0.007 astronomical units, it receives 16 times the radiation intensity that the Earth receives from the Sun. It is also possible that the planet is in constant rotation, like the Moon relative to Earth. This means that one side always faces the star, while the other side is dominated by eternal night. The day side is constantly exposed to intense radiation and its temperature rises to about 280 degrees Celsius on average. Therefore, the planet is not suitable for life as we know it. In such an environment, an atmosphere is also unlikely, according to Gillon's team. A year on SPECULOOS-3b lasts less than one day on Earth, as the planet orbits its star once every 17 hours.
The central star belongs to the category of celestial bodies that lie on the mass boundary between planets and stars. Its diameter is about 167,000 km, which is slightly larger than Jupiter's diameter, which is just under 140,000 km. But its significantly higher mass enables nuclear fusion in its core and makes it glow. SPECULOOS-3 is likely about 6.6 billion years old, making it much older than the solar system. The age of these stars is estimated at more than 100 billion years, which is much longer than the age of the previous universe.
The SPECULOOS-3 star system is an ideal target for future observations using the James Webb Space Telescope (JWST). It can be used to research the nature and composition of the planet's atmosphere and surface.
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