The Mekoria Quasar was a quasar with a high level of energy emissions. In this quasar, there was a protostar with accelerating core gases.

In 2370, the USS Enterprise-D was assigned a mission to study the energy output of this quasar. During this mission, Captain Jean-Luc Picard received a priority one message from Admiral Blackwell. She ordered the Enterprise-D to postpone its mission and proceed to sector 1607 at high warp speed for a rendezvous with the USS Crazy Horse. (TNG: "The Pegasus")

The spelling of the name of the quasar comes from the script of the episode. It is pronounced as "meh-KOR-ree-ah". [1]
A PADD for sale during It's A Wrap! sale and auction showed the name of the quasar as "Mecoria Quasar". [2]