Nether stars (dropped by withers) currently despawn after 10 minutes.

I would have expected them to despawn after 5 minutes, or else never despawn at all / be invulnerable.

This may be works as intended, but if so the MCP names are incorrect.

Edit:

Reproduction steps.

1. Kill a wither.
2. watch the nether star drop.
3. drop a stone block nearby.
4. note the stone block despawning.
5. Note that 5 minutes after the stone block despawns, the nether star despawns.