Hello,
What is the size of the block header?
Could you provide some more context ?
One thing to note is that the block header has a variable size. During protocol upgrade, for instance, it contains additional fields.
Does the block header size vary even during the steady state?
For research, I am just trying to understand how much storage is required to store only the block headers on the disc.
Yes, the block size can vary even on a steady state. In particular, once the state proofs feature would be complete, some block headers ( usually at a constant interval ), would contain the compact certificate, which could be pretty large.
Unfortunately, I don’t have any concrete numbers to provide. If you want to find the block size, you can use the goal utility to dump a block in msgp format, try to remove all the non-header data, and then try to rebuild the msgp data.
Note that while the node does (currently) store the block information in msgp format, it’s not guaranteed to remain the case.