What is the surface of the largest known planetary shield?

This is not a shield, this is a shield UY. Shield is a constellation, and shield UY is a star in the shield.

But the shield UY star has no "surface". It is a gas giant, filled with gas from the inside out. In addition, there is no clear boundary between the "surface" of a star and space. Without high temperature, hot and tumbling gas, it is not considered as the interior of a star.

Humans cannot land on Jupiter either. Jupiter is the largest planet in the solar system and a gaseous planet. The surface of a gaseous planet is not solid, but gaseous. Although scientists believe that Jupiter has a solid core, there is a very deep ocean of methane liquid outside it, and then the surface is filled with gas. Moreover, due to Jupiter's huge mass and great internal pressure, artificial detectors can't bear such high pressure and can't reach deeper below Jupiter's surface at present.