Astronomers found Bernard star's planets after a 100-year hunt.

"For a century, astronomers have been studying Barnard’s Star in the hope of finding planets around it. First discovered by E. E. Barnard at Yerkes Observatory in 1916, it is the nearest single star system to Earth. Now, using in part the Gemini North telescope, one half of the International Gemini Observatory, partly funded by the U.S. National Science Foundation and operated by NSF NOIRLab, astronomers have discovered four sub-Earth exoplanets orbiting the star. " (ScitechDaily, After 100 Years of Searching, Astronomers Confirm Four Planets at Barnard’s Star)

"One of the planets is the least massive exoplanet ever discovered using the radial velocity technique, indicating a new benchmark for discovering smaller planets around nearby stars. Credit: International Gemini Observatory/NOIRLab/NSF/AURA/P. Marenfeld" (ScitechDaily, After 100 Years of Searching, Astronomers Confirm Four Planets at Barnard’s Star)

"This illustration shows Barnard's star, with the correct size and temperature/color, as orbited by the four recently confirmed exoplanets around it. All four exoplanets are close in, with orbits ranging from 2.3 to 6.7 days, and small in mass: between 0.17 and 0.34 Earth masses." (BigThink, Confirmed at last: exoplanets found around nearest single star) (Zoom image)

"Throughout most of the history of astronomy, we knew only of the planets in our own Solar System; the presence or absence of planets around other stars could not be determined. Although the first planets beyond our Solar System, exoplanets, were discovered in 1992, several “false detections,” including around the nearest singlet star to our own, Barnard’s star, came earlier. In 2018, another “false” exoplanet around Barnard’s star was announced, and then refuted in 2021. But now, at last, we’ve found Barnard star’s elusive exoplanets, and they have so much to teach us." BigThink, Confirmed at last: exoplanets found around nearest single star)

Bernard's star has four planets. All of them are sub-earth planets, smaller than Earth. Bernard's star is a very small red dwarf. It's the closest single star to the Sun. 

Slightly larger than Jupiter. And that means the small planets can be seen against that planet. The red dwarf is very close to Earth. The distance between the Sun and Bernard's star is 5.9629 light years. 

Bernard's star is the fourth known individual star. Three components of Alpha Centauri are closer to it. Close distance and dim light make it possible to see those planets when they travel over the star.  And that helps to find those four planets. 

"This artist’s impression shows Barnard b, a sub-Earth-mass planet that was discovered orbiting Barnard’s star. Its signal was detected with the ESPRESSO instrument on ESO’s Very Large Telescope (VLT), and astronomers were able to confirm it with data from other instruments. An earlier promising detection in 2018 around the same star could not be confirmed by these data. On this newly discovered exoplanet, which has at least half the mass of Venus but is too hot to support liquid water, a year lasts just over three Earth days." (Wikipedia, Barnard's Star b)

About 100 years astronomers knew that Bernard's star proprietary movement was wobbling. And that gave the possibility that there are planets around that star. And now astronomers confirmed those planet's existence. Those four planets are revolutionary because they have been hunted for so long. They are also smaller than Earth. 

And now we know the solar system. That has four smaller planets than Earth. All of those planets are very small. And that makes them interesting. The sub-earth existence around that star means that there can be more surprises around red dwarfs. That means there can also be sub-earths in well-known exoplanet systems. 

When we think about Earth and our own solar system we always forget that the Earth is the largest of rocky planets. Only gas giants are larger than Earth. And all other rocky planets are smaller than Earth. This is one way. We can see things when we think about exoplanets. 

https://bigthink.com/starts-with-a-bang/confirmed-exoplanets-nearest-single-star/

https://scitechdaily.com/after-100-years-of-searching-astronomers-confirm-four-planets-at-barnards-star/

https://en.wikipedia.org/wiki/Barnard%27s_Star

https://en.wikipedia.org/wiki/Barnard%27s_Star_b

https://en.wikipedia.org/wiki/List_of_nearest_stars