Ababy star that is still gathering mass in a nebula and has not begun fusion is called

The star is called protostar.

Explanation:

A protostar is a youthful star that is as yet assembling mass from its parent sub-atomic cloud. The protostellar stage is the most punctual one during the time spent outstanding evolution. For a low mass star (for example that of the Sun or lower), it keeps going around 500,000 years.

The stage starts when an atomic cloud part first falls under the power of self-gravity; and an obscure and weight bolstered center structures inside the crumbling section. It closes when the infalling gas is drained, leaving a pre-principle arrangement star, which agreements to later turn into a fundamental grouping star at the beginning of hydrogen combination.

as resources become scarce because of population growth, the growth decreases after few years due to lack of resources and food.

he is very short, and he can only reach halfway up on the elevator buttons. but on a rainy day, he has his umbrella with him, and he uses it to poke the button at the top.