Astronomy/Star and Planet Formation

For 2015, the Astronomy event focused on stellar evolution and star and planet formation.

Molecular Clouds
Molecular clouds, also known as stellar nurseries, are huge clouds of molecular hydrogen gas within the interstellar medium, ranging from about 1 to 600 light years across. These clouds are dense, at least compared to the rest of empty space, with about 100-1000 molecules per cubic cm. Very slowly, gravity will draw particles into a certain area within the cloud; this increase in particles will make an increase in mass of this area, creating a stronger gravitational force that will drag in more particles; this creates a cavity in the cloud, and a proto-star will form in the center of this cloud. There are several events that can speed up this process, such as galaxy collisions (which could send matter or energy through the cloud, creating a stronger gravitational force in one area) and supernovae (which can cause the same things as galaxy collisions).