Stars+-+by

//​ STARS

RCW 108 is a region where stars are actively forming within the Milky Way galaxy about 4,000 light years from Earth.// This is a complicated region that contains young star clusters, including one that is deeply embedded in a cloud of molecular hydrogen. By using data from different telescopes, astronomers determined that star birth in this region is being triggered by the effect of nearby, massive young stars.  Sun-Like Stars - Red Giant - Planetary Nebula - White Dwarf - Black Dwarf

NEBULA A nebula is a cloud of hydrogen gas and dust in space.

STAR A star is a luminous globe of gas producing its own heat and light by nuclear reactions known as nuclear fusion. They are born from hydrogen and helium gas. Surface temperatures range from 2000 celsius to above 30,000 celsius, <span style="font-family: Calibri; font-size: 11pt; line-height: 115%; mso-ansi-language: EN-AU; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-language: AR-SA; mso-bidi-theme-font: minor-bidi; mso-fareast-font-family: Calibri; mso-fareast-language: EN-US; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; msoansilanguage: EN-AU; msoasciithemefont: minor-latin; msobidifontfamily: 'Times New Roman'; msobidilanguage: AR-SA; msobidithemefont: minor-bidi; msofareastfontfamily: Calibri; msofareastlanguage: EN-US; msofareastthemefont: minor-latin; msohansithemefont: minor-latin;"> and the corresponding colours from red to blue-white. The brightest stars have masses 100 times that of the Sun and emit as much light as millions of Suns. They live for less than a million years before exploding as die.The faintest stars are the red dwarfs, less than one-thousandth the brightness of the Sun.

RED GIANT This is a large bright star with a cool surface. It is formed during the later stages of the evolution of a star like the Sun, as it runs out of hydrogen fuel at its centre. Red giants have diameter's between 10 and 100 times that of the Sun. They are very bright because they are so large, although their surface temperature is lower than that of the Sun.

RED DWARF These are very cool, faint and small stars, approximately one tenth the mass and diameter of the Sun. They burn very slowly and have estimated lifetimes of 100 billion years.

WHITE DWARF This is very small, hot star, the last stage in the life cycle of a star like the Sun. White dwarfs have a mass similar to that of the Sun, but only 1% of the Sun's diameter; approximately the diameter of the Earth.White dwarfs are the shrunken remains of normal stars, whose nuclear energy supplies have been used up.

SUPERNOVA This is the explosive death of a star, and often results in the star obtaining the brightness of 100 million suns for a short time. NEUTRON STARS These stars are composed mainly of neutrons and are produced when a supernova explodes, forcing the protons and electrons to combine to produce a neutron star.

BLACK HOLES Black holes are believed to form from massive stars at the end of their life times. The gravitational pull in a black hole is so great that nothing can escape from it, not even light. The density of matter in a black hole cannot be measured. Black holes distort the space around them, and can often suck neighbouring matter into them including stars. SUPERNOVA A supernova is an exploding star that can become billions of times as bright as the sun before gradually fading from view. At its maximum brightness, the exploded star may outshine an entire galaxy. The explosion throws a large cloud of dust and gas into space. The mass of the expelled material may exceed 10 times the mass of the sun. Most supernovae reach maximum brightness a few days after they occur and shine intensely for several weeks. Some fade within months. Others fade over a period of years. Supernovae also differ in the amount and composition of the material that they expel.