How does a star form?

Over a period, particles of matter from space debris coalesce through gravitational forces to form a heavenly body which is rotating and has a spherical. As the matter continues to coalesce, the body becomes denser and the pressure at its centre increases. If the mass of the body is sufficiently large, the high pressure at the centre causes the hydrogen fusion reaction to commence. The mass is then called a proto-star. If the body is still larger the hydrogen fusion activity increases and makes the body glow brightly. The body is then called a star.

What happens when a star starts glowing?

After a star start glowing, it reaches an equilibrium state when the outward explosive force of the hydrogen fusion reaction equals the inward force caused by the star’s gravity. The star will when continue glowing at virtually a steady rate remain at a steady size for a very long period.

 

 

 

What is the shape of the Milky Way galaxy?

The Milky Way galaxy consists of a central core or nucleus with many stars, a disc with many stars distributed in a plane titled at 620 to the celestial equator, and a halo with relatively few stars distributed in an outer region. The Sun is situated about three fifths of the way from the centre of the galaxy.

 

 

 

 

 

 

 

How can proto-stars be detected?

As the interstellar cloud contracts to form a proto-star, it heats up and radiates infra-red rays which can be detected by instruments.

At what stage of the proto-star does the hydrogen fusion reaction start?

The hydrogen fusion reaction starts when the temperature at the core of the star reaches about ten million degrees Celsius.