What is h2 in astronomy?

H II region, also called diffuse nebula or emission nebula, interstellar matter consisting of ionized hydrogen atoms. The energy that is responsible for ionizing and heating the hydrogen in an emission nebula comes from a central star that has a surface temperature in excess of 20,000 K.

What radiation does HII emit?

UV radiation
HII regions are emission nebulae created when young, massive stars ionise nearby gas clouds with high-energy UV radiation. They are composed primarily of hydrogen, hence the name (astronomers use the term HII to refer to ionised hydrogen, HI for neutral hydrogen), and have temperatures of around 10,000 Kelvin.

Where are HII regions found?

H II regions are found only in spiral galaxies like the Milky Way and irregular galaxies. They are not seen in elliptical galaxies. In irregular galaxies, they may be dispersed throughout the galaxy, but in spirals they are most abundant within the spiral arms.

Why are h2 regions pink?

Because this jump is fairly common, HII regions give off a lot of red light. In a tri-color image using red, green and blue filters, HII regions appear pink. HII regions also give off a lot of ultraviolet light due to photons from the transitions where electrons jump into the n = 1 energy level.

Why is hydrogen so important in astronomy?

Not surprisingly, most stars are made mostly of hydrogen. So hydrogen is a key element in our universe, and in the theories of astronomers. As a result, hydrogen atoms across the universe began to absorb background radiation — a pivotal change that the scientists were able to detect in the form of radio waves.

Is hydrogen a atom?

A hydrogen atom is an atom of the chemical element hydrogen. The electrically neutral atom contains a single positively charged proton and a single negatively charged electron bound to the nucleus by the Coulomb force….Hydrogen atom.

General
Symbol	1H
Names	hydrogen atom, H-1, protium, ¹H
Protons	1
Neutrons	0

Where is ionized hydrogen commonly found?

It exists througout galaxies as interstellar gas clouds called HII regions, or as part of the intercloud gas. However, the most spectacular manifestations of ionised hydrogen are the bright emission nebulae that occur when a cloud of neutral hydrogen is ionised by the UV radiation from young, massive stars.

How much hydrogen is in interstellar space?

The actual density of hydrogen as it exist in interstellar space is on the average of about 1 atom per cubic centimeter. In the extremes, as low as 0.1 atom per cubic centimeter has been found in the space between the spiral arms and as high as 1000 atoms per cubic centimeter are known to exist near the galactic core.

Why nebula is red?

Emission nebulae tend to be red in color because of the abundance of hydrogen. Additional colors, such as blue and green, can be produced by the atoms of other elements, but hydrogen is almost always the most abundant.