STAGE ONE NEBULA

What is a Nebula?
A nebula is an interstellar cloud of dust, hydrogen, helium and other ionized gases.

STAGE TWO PROTOSTAR

How is a protostar form?
Over time, the hydrogen gas in the nebula is pulled together by gravity and it begins to spin. As the gas spins faster, it heats up and becomes as a protostar. Eventually the temperature reaches 15,000,000 degrees and nuclear fusion occurs.

STAGE THREE NUCLEAR FUSION

What is nuclear fusion?
nuclear fusion is a nuclear reaction in which two or more atomic nuclei come very close and then collide at a very high speed and join to form a new nucleus. During this process, matter is not conserved because some of the matter of the fusing nuclei is converted to photons (energy). Fusion is the process that powers active or "main sequence" stars.

STAGE FOUR MAIN SEQUENCE

What is main sequence star?
The cloud begins to glow brightly, contracts a little, and becomes stable. It is now a main sequence star and will remain in this stage, shining for millions to billions of years to come.
The H-R diagram tells that star are main sequence.

STAGE FIVE RED GIANT

What is a red giant?
As the main sequence star glows, hydrogen in its core is converted into helium by nuclear fusion. When the hydrogen supply in the core begins to run out, and the star is no longer generating heat by nuclear fusion, the core becomes unstable and contracts. The outer shell of the star, which is still mostly hydrogen, starts to expand. As it expands, it cools and glows red. The star has now reached the red giant phase. It is red because it is cooler than it was in the main sequence star stage and it is a giant because the outer shell has expanded outward. In the core of the red giant, helium fuses into carbon. All stars evolve the same way up to the red giant phase. The amount of mass a star has determines which of the

following life cycle paths it will take from there

STAGE SIX SUPERGIANT

What is a supergiant?
Supergiants have masses from 8 to 12 times the Sun (M☉) upwards, and luminosities from about 10,000 to over a million times the Sun (L☉). They vary greatly in radius, usually from 30 to 500, or even in excess of 1,000 solar radii (R☉). They are massive enough to begin core helium burning gently before the core becomes degenerate, without a flash, and without the strong dredge-ups that lower-mass stars experience. They go on to successively ignite heavier elements, usually all the way to iron. Also because of their high masses they are destined to explode as supernovae.

STAGE SEVEN SUPERNOVA

What is a supernova?
A supernova is a astronomical event that occurs during the last stellar evolutionary stages of a massive star's life, whose dramatic and catastrophic destruction is marked by one final titanic explosion. For a short time, this causes the sudden appearance of a 'new' bright star, before slowly fading from sight over several weeks or months.

STAGE EGIHT BLACK HOLE

What is a black hole?
A black hole is a region of spacetime exhibiting such strong gravitational effects that nothing—including particles and electromagnetic radiation such as light—can escape from inside it.

STAGE EIGHT NEUTRON STAR

What is a neutron star?
A neutron star is a type of compact star that can result from the gravitational collapse of a massive star after a supernova. Neutron stars are the smallest and densest stars known to exist in the Universe; with a radius of only about 11–11.5 km (7 miles), they can have a mass of about twice that of the Sun.

BIRTH Certificate

• Name:Harold
• Color:Bule
• Temp:7500-11000
• Absolute magnitude: 1000