How do astronomers think the sun may have started?

Answer 1

The sun may have started from the nebula of our solar system. The nebula was mostly made of dust and gasses, and slowly condensed most of it's materials to one area, and eventually, pressure was great enough that nuclear fission could occur. Nuclear fission is a continuing explosion that provides the sun with energy, and light. That's how the sun was formed!

~The rest of the material of the nebula formed the rest of the planets in the solar system.

Answer 2

Our Sun is about 4.5 x 109 years old, and is a normal main sequence star.

Check out Hertzsprung - Russell diagram.

It is essentially 75% hydrogen and 25% helium.

It was formed along with the rest of the Solar system by the accumulation of gas and dust.

Our Earth contains a much greater proportion of heavy elements, so it accumulated from debris left over from a Super Nova explosion, for a star such as our Sun is not massive enough to manufacture elements heavier than iron.

The age of the Universe is about 13 x 109 years.

Answer 3

The best guess that scientists have for the origins of the solar system is the Solar Nebula Hypothesis.

A star or a number of stars exploded leaving a dispersed cloud of various elements and particles in space. Objects with mass are attracted to other objects with mass so the atoms in the cloud begin to accumulate. Within the centre of the accumulation, there is a higher pressure and therefore a higher temperature. At temperatures exceeding 10000K, a protostar may form in the centre of the accumulation. Surrounding the protostar is a disk of various gases and atoms and particles. This disk is prevented from collapsing because the system is rotating.

Within the disk, stuff starts to happen. Elements that can solidify at higher temperatures do so in closer proximity to the protostar (which becomes the Sun), elements that solidify at lower temperatures do so further away from the young Sun. These solids form planets through the process of cold accretion. Planets closer to the Sun are mainly composed of elements that solidify at high temperatures. The formation of planetoids prevents other planets from beginning to form by using up all of the available surrounding materials.

Solar wind blows excess material away into space.

Answer 4

Astronomers believe the Sun formed from a cloud of gas and dust in space, known as a solar nebula, about 4.6 billion years ago. The gravitational forces within the nebula caused it to collapse and form a protostar, which eventually became the Sun through the process of nuclear fusion.