It's the largest number of worlds ever discovered in a planetary system outside our own.
The star known as Kepler-90, is just a bit hotter and larger than the Sun; astronomers already knew of seven planets around it.
The newly discovered world is small enough to be rocky, according to scientists.
"This makes Kepler-90 the first star to host as many planets as our own Solar System," said Christopher Shallue, a software engineer at Google, which contributed to the discovery.
