In Exodus, what object did Aaron make from gold while Moses was on Mount Sinai?

In Exodus, Aaron makes a golden calf while Moses is on Mount Sinai.

Moses remains on the mountain for forty days and forty nights. When the people do not know what has happened to him, they ask Aaron to make gods who can lead them. Aaron collects their gold earrings, casts the metal, and fashions a calf. The Israelites then hold a festival involving sacrifices and celebration.

Moses comes down carrying the stone tablets of the covenant. On seeing the calf and the dancing, he throws down and breaks the tablets at the foot of the mountain. Exodus portrays the episode as a grave violation of the covenant, especially the prohibition against making and worshipping images of other gods.

Aaron's role is important because he is Moses's spokesman and Israel's first high priest, yet this episode shows him yielding to the crowd. The golden calf is not the same object as the bronze serpent later associated with Moses in Numbers, nor is it a crown or an eagle.