Hi I am a level 48 master necromancer and I have finished the Warehouse and gave the broken Celestia key to Professor Balestrom and have been waiting for one day and he has not contacted me to give it back yet. :( I just want to know if i have to be a grandmaster or if I need to finish Dragonspyre or simply wait longer. Please reply I do not want to wait forever. Thanks :)
Celestia isn't available on the open servers/realms yet. It is scheduled to open sometime next month. When Celestia opens, everybody eligible to go there (or to do whatever quests are necessary to go there) will get a message from whoever will be in charge (probably Professor Balestrom).
According to KingsIsle, you won't need to be a Grandmaster to go to Celestia. Currently, the requirement is to have beaten Malistaire. Whether they add additional requirements later is unknown at this point.