According to Clark (2012), Astronomers have measured the background light from all the
stars in the cosmos and inferred the number of stars created since the dawn of the
universe. The operation was performed using NASA’s Fermi Gamma-ray Space Telescope.
Emissions were detected from gamma ray emitting supermassive black holes at the centers
of galaxies to undertake the experiment. The study concluded that the universe has an
average of 1.4 stars per 100 billion cubic light-years and first stars were formed when the
universe was almost 400 million years old.
Study of stars, their formation and their count has always fascinated astronomers. Study of
stars lie at the heart of Astronomy and drives it in most of the cases. Star formation is an
extensive and complex process. ‘A star is formed out of cloud of cool, dense molecular gas.
In order for it to become potential star, the cloud needs to collapse and increase in density’
(Cain 2009).
Stars are born in nebulae and huge clouds of gas collapse and mix under gravitational
forces to form protostars. Protostar is the first phase in the life cycle of a start and the
process of formation of a protostar takes around 10 million years. The life cycle of stars
forms a pattern based upon the kind of stars they are (i.e. Sun-Like stars, Huge Stars and
Giant Stars). Stars expand throughout their life span and during the course their core
consumes all the hydrogen and helium. At the end of their life cycles, Sun-like stars end up
as Black Dwarfs, Huge stars complete their journey by becoming Neutron stars while Giant
stars die as Black Holes. The life cycle of a star is very long and lasts over millions of years.
There have been many experiments to study stars and various aspects related to it for
years now, but the magnificence of stars still amazes and attracts astronomers.
References
Clark, Stephen (2012), NASA’s Fermi helps calculate number of stars in universe, Spaceflight
Now, Retrieved from: http://www.spaceflightnow.com/news/n1211/01fermi/#.UJQAEBhJ9G4
Cain, Fraser (2009), How does a Star Form?, Universe Today
Retrieved from: http://www.universetoday.com/24190/how-does-a-star-form/
