Scientists have located a “Super Earth” that is believed to orbit one of the oldest stars in the Milky Way galaxy. The exoplanet gets its title, as it is suspected to be about three times the mass of Earth, with a size 50% larger than our home planet.
The planet, known as TOI-561b, has been described in a new study accepted for publication in The Astronomical Journal. Despite the mass of the planet, its density is almost the same as that of Earth, according to astronomers in the study.
“We report the discovery of TOI-561, a multi-planet system on the galactic thick disk that contains a rocky, ultra-short-period (USP) planet,” the study notes.
The planet gets its name from the Transiting Exoplanet Survey Satellite (TESS) planetary hunting mission conducted by NASA in 2018. The “TOI” of TOI-561b means TESS Object of Interest. It is located outside the solar system, on the thick galactic disk of the Milky Way, says a CNN report. Due to its proximity to the host star, it only takes less than half the Earth’s day to complete an orbit around it.
“For every day you’re on Earth, this planet revolves around its star twice,” Stephen Kane, co-author of the study and astrophysicist at the University of California, Riverside, said in a statement. The researchers determined the mass, radius and density of the planet using the WM Keck Observatory in Hawaii.
(Representative image: Reuters)
This close proximity to the “super-Earth” causes the average surface temperature of the planet to exceed 2,000 Kelvin, or 3,140 degrees Fahrenheit. The TOI-561b is therefore too hot to be habitable. Although since astronomers know that the rocky planet and its star form a 10 billion-year-old system, they wonder if the planet hosted life at some point in its past.
“TOI-561b is one of the oldest rocky planets ever discovered,” study author Lauren Weiss said in a statement. “Its existence shows that the universe has been forming rocky planets almost since its inception 14 billion years ago.” In comparison, our sun is only 4.5 billion years old.
These older planets are considered to be less dense than the more recently formed planets. This is because there were not so many heavy elements present in the universe at that time. These elements have finally been created by stars that ended up with a supernova.
The study highlights two other planets orbiting the star, which are probably gaseous and larger than TOI-561b.