There isn't one specific star directly "under" the Big Dipper. The Big Dipper is an asterism (a recognizable pattern of stars) within the constellation Ursa Major (the Great Bear).

Here's why there's no single star directly "under" the Big Dipper:

* Perspective: The Big Dipper appears to be a dipper shape from our perspective on Earth. But the stars are at vastly different distances from us.

* No single "bottom" star: The Big Dipper doesn't have a defined bottom. It depends on how you view the asterism.

Some stars near the Big Dipper:

* Polaris (North Star): While not directly under, Polaris is a prominent star found by extending the two stars at the end of the Big Dipper's bowl (Dubhe and Merak) upwards.

* Stars in Ursa Major: The Big Dipper's stars are part of the larger Ursa Major constellation, and there are many other stars in that constellation.

Let me know if you want to know more about any of these stars or the Big Dipper!