STARS

       

                             

STARS

                                                                                                                                                                                                                                                                                              When you look at the night sky you can see many stars.if you are out in the country or camping in the mountains or the desert away from the city lights,you may see thousands of them.you may even be able to see part of the milky Way.In a town or city,you can’t see nearly as many stars because the city lights create a glow in the sky masking many of them.

              There are several different kinds of stars in the sku.some are very big.a couple of stars have been found that are 100-200 times larger than the sun. sun very old stars are smaller than the earth.scientists study stars and place them in groups based on how they are alike and how they are different.                                                                        

DIFFERENT TYPES OF STARS

NO – 1  RED DWARF STARS    

      

A red dwarf is a small and relatively cool star on the mainsequence, either late K or M spectral type. Red dwarfs range in mass from a low of 0.075solar masses (the upper limit for a brown dwarf) to about 50% of the Sun and have a surface temperature of less than 4,000k.

Red dwarfs are by far the most common type of star in the Milky way galaxy, at least in the neighborhood of the Sun, but due to their low luminosity, individual red dwarfs cannot easily be observed. From Earth, not one is visible to the naked eye.^[1] proxima centauri, the nearest star to the Sun, is a red dwarf (Type M5, apparent magnitude 11.05), as are twenty of the next thirty nearest. According to some estimates, red dwarfs make up three-quarters of the stars in our galaxy.

Stellar models indicate that red dwarfs with less than 35% of the Sun’s mass are fully convective. Hence the helium produced bythermo nuclear fusion of hydrogen is constantly remixed throughout the star, avoiding a buildup at the core. Red dwarfs therefore develop very slowly, having a constant luminocity and spectral type for, in theory, some trillions of years, until their fuel is depleted. Because of the comparatively short age of the universe, no red dwarfs of advanced evolutionary stages exist.

NO – 2  YELLOW DWARF

Yellow dwarfs are small, main sequence stars. The Sun is a yellow dwarf. 

NO – 3 BLUE GIANT

A blue giant is a huge, very hot, blue star. It is a post-main sequence star that burns helium. 

NO - 4 WHITE DWARF

A white dwarf is a small, very dense, hot star that is made mostly of carbon. These faint stars are what remains after a red loses its outer layers. Their nuclear cores are depleted. They are about the size of the Earth (but tremendously heavier)! They will eventually lose their heat and become a cold, dark black dwarf. Our sun will someday turn into a white dwarf and then a black dwarf. The companion of Sirius is a white dwarf.  

NO – 5 BROWN DWARF

A brown dwarf is a "star" whose mass is too small to have nuclear fusion occur at its core (the temperature and pressure at its core are insufficient for fusion). A brown dwarf is not very luminous. It is usually regarded as having a mass between 10²⁸ kg and 84 x 10²⁸.   

                                                                                         

A star is a massive luminous sphere of plasma held together by its own gravity. The nearest star to earth is the Sun, which is the source of most of the planet's energy. Some other stars are visible from Earth during the night, appearing as a multitude of fixed luminous points due to their immense distance. Historically, the most prominent stars were grouped into constallations and asterisms, and the brightest stars gained proper names. Extensive catalogues of stars have been assembled by astronomers, which provide standardized star designations