Yes we can hide them. But I am not sure that specific objects could be hidden.

Highlight the server in SQL Server Enterprise Manager, right click and select Edit SQL Server Registration properties... from the pop-up menu.

In the Registered SQL Server Properties dialogue box, remove the tick from Show system databases and system objects. This will only hide the system objects for that specific SQL Server. You must do this for each SQL Server you have registered in SQL Server Enterprise Manager.

In SQL Server 2005's new tool called Management Studio, go to Tools / Options / Environment / General and choose "Hide system objects in Object Explorer."