Protostar
A protostar was a star in the earliest stage of development, when interstellar gas was still undergoing gravitational collapse and nuclear fusion at the core has just begun. The Argolis Cluster was an example of a protostar cluster. ()

In June of 2151,  surveyed a protostar, one week before the incident at the Vulcan monastery at P'Jem. This protostar was not listed on the Vulcan star charts. ()

When the  was thrown into the Triangulum Galaxy in 2364, it stopped near a giant protostar in the process of formation. ().

In 2366, the Enterprise-D conducted a study of a protostar cloud. ()

Collapsing protostars sometimes emit E-band bursts. Protostars were ruled out as a cause for an E-band emission detected on the Enterprise-D in 2367, because there were no protostars within the sector. ()

In 2369, the Enterprise-D analyzed several dozen protostars at various stages of development in the Volterra Nebula. ()

Protostars are often marked by high levels of magnetascopic interference, which impair sensor function. While undercover with the Maquis in 2370, Ro Laren used a protostar in the Topin system as cover to steal medical supplies from the Enterprise-D. ()

In 2371, the  discovered a protostar with unusually intense photonic activity. They collected samples of photonic matter in the hopes of improving their systems, but found that they had in fact captured photonic lifeforms native to the star. ()

In theory, a type-6 protostar could be used to generate a wormhole that could bridge the Delta Quadrant and Alpha Quadrant. ()

The  surveyed a cluster of protostars in the Gamma Quadrant in 2373. ()

The following year, during the Dominion War, Jadzia Dax commanded the Defiant on a mission in the Argolis Cluster to destroy a Dominion sensor array. She had studied protostar clusters and would be able to recognize the gravimetric distortions from them. ()

By the 2380s, Starfleet was able to harness the power of a protostar, referred to in technical terms as a proto-core, creating a new type of experimental propulsion enhancement system that was used in the  alongside traditional warp. It was considerably faster than a conventional warp drive. This experimental  vessel was built with a gravimetric protostar containment. ()

External link
 
de:Protostern
fr:Protoétoile
it:Protostella
ja:原始星
nl:Protoster
sr:Протозвијезда
Celestial objects