For ten hours, the star HD 137010 dimmed a little, like a lamp with a speck of dust on it. The K2 telescope caught this in 2017, and in all the observing time, it happened only once. Astronomers realized: a planet had passed in front of the star.
This way of finding worlds is called the transit method. When a planet crosses the star's disk, the star briefly fades. The bigger the planet, the deeper the dip. Here, the dip was tiny — the star lost just 225 parts per million of its brightness. But the telescope was so sensitive that the signal was clear.
The planet orbits its star in about 355 Earth days — almost exactly our year. It sits at 0.88 times the distance from Earth to the Sun. HD 137010 is an orange dwarf, slightly cooler and dimmer than the Sun, so the planet receives only 29% of the heat that reaches Earth. That's closer to the cold edge of the habitable zone, where water could stay liquid.
Astronomers haven't found planets like this, similar to Earth in both size and year, around bright stars before. Previous candidates were only around dim red dwarfs, which are hard to study. But HD 137010 is bright enough that future telescopes could probe its atmosphere and look for signs of life.
If you stood on HD 137010 b, the star would look larger than the Sun, but it would feel three times weaker, like a radiator turned down to the lowest setting.