Ind. Code § 5-8-1-18

Sec. 18. In case impeachment proceedings be pending in the senate at the time of the expiration of any session of the general assembly, the senate shall be continued in session for the sole and only purpose of sitting as a court of impeachment until such impeachment proceedings be concluded, and may, pending the conclusion of such impeachment proceedings, adjourn from time to time, as it may deem expedient.