Question

As a star forms, place the following in order of their occurrence.1. A cloud contracts under gravity.2.A disk forms because angular momentum is conserved.3. Nuclear reactions begin and a star is born.4. Clumps form from static electricity.5.Planetesimals form from collisions.6. A wind blows from the central star.

Answer 1

The formation of stars starts with a molecular cloud contracting due to gravity, forming a protostar and a surrounding disk. Nuclear reactions begin, creating a star, which generates a stellar wind and leads to the creation of planetesimals from the disk materials.

Step-by-step explanation:

Understanding the formation of stars is a key aspect of astrophysics. The process begins in a molecular cloud and involves several stages before a star reaches the main sequence of its lifecycle.

1. A cloud of gas and dust contracts under the influence of its own gravity.
2. As it collapses, a protostar is formed and with conservation of angular momentum, a disk-like structure is formed around the protostar due to rotation.
3. As the protostar continues to accumulate mass and density, nuclear reactions commence. This signifies the birth of a new star.
4. The stellar wind then emanates from the newly formed star, which can interact with the surrounding medium.
5. The disk around the star cools and condenses, leading to the formation of planetesimals, which are the building blocks for planets.

The molecular clouds contain regions of higher density known as clumps, and within these clumps, even denser cores are present, each potentially becoming a star. These steps are observed in star-forming regions like the Orion Nebula using telescopes such as the Hubble Space Telescope.