See the map of New York. Wikipedia article: New York. Find out the distance between New York and other cities. Find out the distance between New York and the North Pole, the South Pole, the Equator, the Tropic of Cancer, the Tropic of Capricorn, the Arctic Circle, the Antarctic Circle.
The outer layers begin to expand, cool and shine less brightly. The expanding star is now called a Red Giant. The star expands to a Red Giant, below. Stage 8 - The helium core runs out, and the outer layers drift of away from the core as a gaseous shell, this gas that surrounds the core is called a Planetary Nebula.A Planetary Nebula. (Below, NGC 6543).he outer layers begin to expand, cool and shine less brightly. The expanding star is now called a Red Giant. The star expands to a Red Giant, below. Stage 8 - The helium core runs out, and the outer layers drift of away from the core as a gaseous shell, this gas that surrounds the core is called a Planetary Nebula.
The first is a nebula's proximity to the star, and the second is the star's temperature. When a nebula is very close to a hot star, it can absorb large amounts of ultraviolet radiation.This heats the gas to about 10,000 Kelvin (9,726 degrees Celsius or 17,540 degrees Fahrenheit).At such extreme temperatures, the hydrogen gas becomes excited and glows with a fluorescent light.ourtesy NASA and STScIThe Orion Nebula is an emission nebula. It is illuminated and heated by four massive stars known as the Trapezium, which lie near the center of the image. Astronomers generally classify nebulae into two broad categories -- bright and dark.