Two Earth-like planets have been discovered near a star close to us. Here's what we know about this exciting find.

Astronomers have discovered two new planets that are remarkably similar in size to Earth. To be precise, they are extremely alike. However, there is one issue: these planets are located very close to their host star. The research has been published on the arXiv preprint server, reports Phys.

The TESS space telescope has been searching for exoplanets for six years. During this time, astronomers have identified 7,300 candidates for the title of planet, with nearly 600 of these worlds having their planetary status confirmed. Now, scientists have not only found two new worlds outside the Solar System but have also confirmed through further observations that these are indeed Earth-sized planets.

What is interesting about orange dwarf stars?

The two planets orbit the star HD 101581, located nearly 42 light-years away from us. In cosmic terms, this is a relatively close distance. The star HD 101581 belongs to the class of orange dwarfs. It is almost 40% smaller than the Sun and has about 35% less mass than our star. Scientists estimate the age of HD 101581 to be around 7 billion years, with a surface temperature of nearly 4,400 degrees Celsius.

In comparison, our Sun has existed for approximately 4.6 billion years, with a surface temperature of 5,500 degrees Celsius. The Sun is classified as a yellow dwarf, and such stars typically live for about 10 billion years. However, orange dwarfs can live between 15 to 30 billion years. Interestingly, these stars do not exhibit as much activity as the Sun, leading some scientists to believe that rocky planets orbiting them may be worth investigating for signs of extraterrestrial civilizations.

It should be noted that life is likely impossible on the two discovered planets orbiting HD 101581, as these worlds are situated very close to their star.

What is known about the new Earth-like planets?

• Scientists have found that the diameter of the planet closest to the star, named HD 101581 b, is only 5% smaller than that of Earth. Its mass is approximately 3.6 times that of Earth. The temperature on HD 101581 b is around 560 degrees Celsius, which is higher than that of the hottest planet in the Solar System—Venus (with temperatures ranging from 450 to 480 degrees Celsius). Due to its proximity to the star, at just 0.046 astronomical units (about 6.9 million km; for comparison, the distance between Earth and the Sun is nearly 150 million km), HD 101581 b completes one orbit around its star in just 4.5 Earth days.
• The more distant planet, named HD 101581 c, is located 0.057 astronomical units (approximately 8.5 million km) from its star. Its diameter is just 1% smaller than that of Earth, but its mass is about 4.2 times greater than that of our planet. The temperature on HD 101581 c is comparable to that of Venus, at around 470 degrees Celsius. The orbital period of this planet is slightly over 6 Earth days.

Is there a third Earth-like planet?

Astronomers believe that there may also be a third planet, similar in size to Earth, orbiting the star HD 101581. Its presence still needs to be confirmed. Calculations suggest that this planet could have a mass 3.6 times greater than that of Earth, with a diameter just 2% smaller than our planet. The orbital period of this planet is estimated to be nearly 8 Earth days.

According to the study's findings, the star HD 101581 is the brightest known star that has several planets orbiting it, all smaller than 1.5 times the diameter of Earth.