Dark Nebula -- Part 5 to Part 6

Dark nebula or nebula absorption
Is a kind of interstellar medium where it is found in interstellar space and consists of gas and dust at a relatively high intensity so that it obscures the light coming from its stars. The dark nebula is the origin of the next generation of stars where parts of the material pull under gravity to form a new star. When the mass of a substance reaches a certain limit (about half of the mass of the sun), the temperature of its interior has risen to about 10 million degrees or more and the pressure in its heart reaches a high pressure It is enough to start a nuclear fusion that turns hydrogen into helium. The star gets warmer and produces light.
The nebula's temperature is low so that no light is visible, but it may emit infrared and low-power radio waves

Analysis of the dark nebula

The properties and components of dark nebula can be determined by spectral analysis (by spectroscopy): by measuring spectral spectra behind the cloud of the dark nebula, as some of the spectral lines absorbed by the dark cloud material disappear from the star spectra, Located in the cloud of the dark mist. That is, the spectrum of the star next to us shows black lines indicating what the cloud absorbs from spectrum lines, where the atoms or particles in the nebula absorb the wavelengths of light they indicate.

Under the influence of radiation from the large star that ionizes and presses the tips of the cloud as well as the star wind coming from the emerging stars, removing the gas and dust from the center outwards, this leads to a great compressive urge in the nebula. This pressure has helped start the emergence of a number of current generation of young stars

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Nebula is the birthplace of stars -- Part 1

Planetary Nebula -- Part 2

Emission Nebula -- Part 3

Reflection Nebula -- Part 4

Dark Nebula -- Part 5 The Post has been added

Supernova Remnants -- Part 6