What is a quorum in the senate for the purpose of trying impeaching?

In the U.S. Senate, a quorum for the purpose of trying impeachments requires a majority of the Senate's membership, which is currently 51 senators, given that there are 100 senators in total. This means that at least 51 senators must be present for the Senate to conduct an impeachment trial. If a quorum is not present, the trial cannot proceed.