There were at least three
Merchant vessels with the name WHITE STAR around in 1861.
This seems the most likly one.
WHITE STAR Official Number 1141, Built St John New Brunswick in 1854, 2339 toms, owned in 1861 by Wilson and Co. Liverpool. (Partner in the first White Star Line) Port of Registry Liverpool. Wrecked 24/12/1883.
Her 1861 Logbooks and Crew Agreements, which will tell you if your man was on board and should
give you details to where he signed on and was discharged.
These documents are stored in The National Maritime Museum, Greenwich. It seems they are closed at the moment due to Covid 19.
You should be able to obtain copies via this form whenever they reopen.
https://www.rmg.co.uk/national-maritime-museum/caird-library/crew-lists-agreements-official-logs-request-formBe sure to ask for the Crew Agreement and Logbook covering the date 07/April 1861.