Question

Розповідь як народжуються зірки

Answer 1

Когда звезды подмигивают нам с ночного неба, вряд ли мы задумываемся о том, что видим их такими, какими они были сотни и тысячи лет назад. Именно столько требуется фотонам, чтобы достичь наших глаз, двигаясь со световой скоростью. 

                        
Многие из далеких солнц, вероятно, уже давным-давно погасли, другие, пока невидимые для нас, уже успели родиться. Об их появлении рано или поздно узнают наши потомки.

Answer 2

How Stars are Born

Stars are born through a process called stellar formation, which occurs in dense regions of interstellar gas and dust known as molecular clouds. The formation of stars involves several stages, starting from the collapse of a molecular cloud to the formation of a protostar and eventually the ignition of nuclear fusion in its core.

1. Molecular Clouds and Gravitational Collapse Molecular clouds are vast regions of gas and dust in space, primarily composed of molecular hydrogen. These clouds can span several light-years in size and contain enough material to form thousands of stars. Within these clouds, regions of higher density, known as dense cores, begin to collapse under their own gravity.

2. Protostar Formation As a dense core collapses, it forms a rotating disk of gas and dust around a central concentration of material called a protostar. The protostar continues to accrete matter from the surrounding disk, growing in size and mass. During this phase, the protostar is not yet hot enough to sustain nuclear fusion in its core, and it emits infrared radiation as it releases gravitational energy.

3. Nuclear Fusion and Star Formation When the protostar reaches a critical mass, the temperature and pressure at its core become high enough to initiate nuclear fusion. Nuclear fusion is the process by which hydrogen atoms combine to form helium, releasing an enormous amount of energy in the form of light and heat. This marks the birth of a star, and it enters the main sequence phase, where it will spend the majority of its lifetime fusing hydrogen into helium in its core.

4. Stellar Evolution Once a star is formed, its evolution is determined by its initial mass. Stars with lower masses, like our Sun, will remain on the main sequence for billions of years before eventually evolving into red giants and then white dwarfs. Higher-mass stars, on the other hand, have shorter lifetimes and undergo more dramatic transformations, such as becoming supernovae or collapsing into black holes or neutron stars.

In summary, stars are born from the gravitational collapse of dense cores within molecular clouds. As the collapsing material forms a protostar, it continues to accrete matter until it reaches a critical mass, at which point nuclear fusion ignites in its core. This fusion process releases energy and marks the birth of a star, which will go on to follow a unique evolutionary path based on its initial mass.

I hope this information helps! Let me know if you have any further questions.