Every day, dozens of Astronomers “comb” the night sky in search of other planets outside our Solar System. For example, NASA has discovered more than 4,500 exoplanets in total, about 50 of which are believed to be potentially habitable.
This week, a group of specialists published a scientific study in which they detail “A rocky and hot super-Earth”, near one of the oldest stars in the galaxy, which has taken them by surprise. The planet is about 50% larger than Earth, but it takes less than half a day to orbit its star. “For every day you’re on Earth, this planet orbits its star twice,” said UC Riverside planetary astrophysicist and member of the team that made the find, Stephen Kane.
The planet, known as TOI-561 b, orbits the TOI-561 star system, according to a study published in The Astronomical Journal. “The planet orbiting TOI-561 is one of the oldest rocky worlds discovered so far ”, said the study’s lead author, Lauren Weiss, in a release. Its existence shows that the universe has been forming rocky planets almost since its inception. 14 billion years ago ”.
Part of the reason for the short orbit is the proximity of the planet to its star, which also creates incredible heat. Its estimated average surface temperature is over 1,700 degrees Celsius, too hot to house life as we know it today, although it may once have been possible. Additionally, Kane said that although the planet is about three times the mass of Earth, the team calculated that its density is the same as our planet.
“This is surprising because the density would be expected to be higher “Kane said in a statement. “This is consistent with the notion that the planet is extremely old”, He added. The older a planet is, the less dense it is likely to be because there weren’t as many heavy elements available when it formed, Kane explained. Heavy elements are produced by fusion reactions in stars as they age. Eventually the stars explode, dispersing these elements from which new stars and planets will form. TOI-561, which has at least two other planets orbiting around it.
As researchers discover more exoplanets, they continue to learn more about their mass and radius and whether they could be habitable. “Information about the interior of a planet gives us an idea of whether the planet’s surface is habitable for life as we know it. Although this particular planet is unlikely to be inhabited today, it may be a harbinger of many rocky worlds yet to be discovered around the oldest stars in our galaxy, ”Kane explained.
The TESS Object of Interest (TOI) 561, named after NASA’s transiting exoplanet study satellite, belongs to a rare population of stars called the galactic thick disk. The stars in this region are chemically distinct, with fewer heavy elements such as iron or magnesium that are associated with planet building.
The TESS Mission team used the University of California’s access to the WM Keck Observatory in Hawaii, home to some of the most scientifically productive telescopes on Earth, to confirm the presence of planet TOI-561b. The observatory team also helped the team calculate the mass, density and radius of the planet.
Astronomers are continually trying to understand the relationship between the mass and radius of the planets they encounter. This information provides information on the interior structure of planets that, with current technology, are too far away to visit and sample.