Question

Из чего образованны звезды?Очень срочно!!!!¡¡¡¡

Answer 1

Человечество пока не может проникнуть внутрь звезд и сказать достоверно, какова их природа. Исследователи изучают звезды, наблюдая лишь их внешние проявления: размеры и светимость. Остальные параметры и процессы, происходящие внутри звезд, рассчитываются косвенными методами, т.е. с помощью математики и компьютерного моделирования.

Звезда представляет собой огромных размеров шар, который состоит из раскаленного до высокой температуры газа. Как известно, любой газ имеет свойство быстро расширяться, чтобы занять определенный объем. Любой газ обладает определенным давлением. Сила давления газа направлена на расширение звезды. Но звезда не расширяется, потому что внешние ее слои противодействуют силе давления газа и силой тяжести уравновешивают последнюю.

Answer 2

73% водорода и 25% гелия

Answer 3

Formation of Stars

Stars are formed through a process known as stellar formation or star formation. Stars are born from vast clouds of gas and dust called molecular clouds. These clouds are primarily composed of hydrogen gas, with smaller amounts of helium and trace amounts of other elements.

The formation of stars involves several stages, including the collapse of a molecular cloud, the formation of a protostar, and the eventual ignition of nuclear fusion in the core of the protostar. Here is a brief overview of the process:

1. Collapse of a Molecular Cloud: Molecular clouds are massive and cold regions in space where stars are born. Gravitational forces cause these clouds to collapse under their own weight. As the cloud collapses, it fragments into smaller clumps, each of which can potentially form a star.

2. Formation of a Protostar: Within one of these collapsing clumps, the material continues to collapse and form a dense core called a protostar. The protostar continues to accrete more material from its surrounding cloud, growing in size and mass.

3. Protostellar Disk Formation: As the protostar continues to accrete material, a rotating disk of gas and dust forms around it. This disk is known as a protostellar disk or a circumstellar disk. The disk plays a crucial role in the formation of planets and other celestial bodies.

4. Ignition of Nuclear Fusion: As the protostar continues to accrete material and its core becomes denser and hotter, the temperature and pressure at the core eventually become high enough to initiate nuclear fusion. Nuclear fusion is the process in which hydrogen atoms combine to form helium, releasing a tremendous amount of energy in the form of light and heat. This marks the birth of a star.

5. Main Sequence Star: Once nuclear fusion begins, the star enters the main sequence phase, where it will spend the majority of its lifetime. The star will continue to burn hydrogen in its core, maintaining a stable balance between the inward pull of gravity and the outward pressure generated by the fusion reactions.

It's important to note that the process of star formation is complex and can vary depending on factors such as the mass of the collapsing cloud and the presence of nearby stars. Additionally, the formation of stars is an ongoing process in the universe, with new stars constantly being born while others reach the end of their lives.

I hope this provides a detailed explanation of how stars are formed. Let me know if you have any further questions!