FGC 47 was a nebula composed primarily of helium, hydrogen, and trionium, centered around a neutron star. It also contained a dense web of plasma energy strands. The nebula was inhabited by a group of non-corporeal lifeforms which fed on the energy.
The USS Enterprise-D investigated the nebula in 2368 as part of its exploratory mission. The entities living in the nebula viewed its crew as a possible threat, and found that its energy systems were far purer than those normally present in the nebula. As a result, they began draining energy from the starship, which was slowed in its attempts to depart the nebula by the presence of the energy strands. When convinced by Jean-Luc Picard that they were not a threat, the Enterprise was allowed to leave.
The nebula's name was given a standard FGC designation, but Geordi La Forge attempted to convince Data that the formation should be named "La Forge's Nebula", though Ensign Daniel Sutter preferred "Sutter's Cloud". (TNG: "Imaginary Friend")