Hello, steemians today I bring you a new post of astronomy 101, this time I will talk about one of the most used techniques for the exploration of our great universe. This is the spectroscopy, perhaps one of the first techniques to be used and perhaps also the technique that helped to lay the foundations for the development of new methods of detection and exploration of the universe.

So as I always tell you, don't waste any more time and let's start.

Being unable to even launch manned exploration missions whenever we want and where we want the scientists over time have had to devise a number of tools and methods for observing the universe, either through probes, telescopes, satellites observation, etc. However, one of the ways we have to observe what exists out there in space is undoubtedly through the light we can perceive of the objects that are in space; that "light" is nothing more than electromagnetic radiation generated by each of said.

And this is where astronomical spectroscopy comes in.

Spectroscopy is responsible for analyzing and studying electromagnetic radiation emitted by objects.

That is to say that astronomical spectroscopy is specifically the means used by scientists to study and analyze the electromagnetic radiation emissions of stars and other bodies that are found in the universe. By using this method you can get to know some of the properties of objects that are in the cosmos, in addition to the chemical composition and orbits or movements that these objects follow if this technique is used in combination with the Doppler effect.

An interesting fact is that helium was the first element that was known in the observation of the Sun's spectrum, and is that it was known before being discovered on Earth.

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Principle of operation of astronomical spectroscopy.

It is possible to extract information from any object that generates or emits light since all the elements have a signature similar to human DNA, but which is manifested through a specific type of wave. It is here where spectroscopy acts, taking advantage of this quality that these objects possess for studies and analysis to determine their composition.

Let me clarify it a little more, if, for example, we illuminated a prism of glass with a beam of white light, the light would decompose in the colors of the rainbow but if in the path of the beam of light we put a gas it would absorb the photons of light of very specific wavelengths leaving their trace in the spectrum in the form of absorption lines, and depending on the chemical nature of the interposed gas these absorption lines will be different, which allows us to know at a distance the chemical composition of distant galaxies only by the light that comes from them.

Summarizing it a little more, each element generates a certain type of behavior when it is put in interaction with light, so astronomers have been able through it to study the emission and absorption lines that appear in these spectra, which are the "traces" of atoms and molecules determine certain chemical and physical properties.

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Spectroscopy and the Doppler effect.

As I commented a few paragraphs ago, through spectroscopy it is also possible to know the movement of some of the objects that are found in the universe. All this thanks to the study of the spectral lines, since these can be used to determine what type of shift possess the bodies that are in space even when they are extremely distant.

For example, when a planet orbits around a star, it will be performing a gravitational force on that star no matter how light it is. What will make the star also orbit over the center of mass of the system formed , then these orbital movements generate a certain type of waves that can be detected and analyzed to observe the changes in the spectral lines of the stars, that is, to determine if it approaches us (shift towards blue) or moves away (redshift).

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Spectroscopy and Redshift.

One of the discoveries that were determined through the use of spectroscopy was the redshift; which basically is a phenomenon that occurs when the radiation emitted by an object is displaced so that it is located at the end of the electromagnetic spectrum.

In astronomy, we refer to redshift when there is a departure from any of the bodies that exist in space.

It should be noted that the distance of the galaxies was theorized under a law that was predicted by A. Fridman and subsequently demonstrated by E.Hubble

This law basically establishes the principle that there are no privileged observers in the Universe. It also states that as a result of the Doppler effect, the movement of the galaxies causes them to move away in such a way that their emission lines are located on the side red of the spectrum.

As you have been able to realize, thanks to the implementation of spectroscopy, it has been possible not only to explore unknown distances but also to determine many of the physical and chemical properties of bodies in the universe, no matter how far they are.

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References.

• Spectroscopy
• Astronomical spectroscopy
• Spectroscopy
• What is redshift
• The Doppler Effect and Star Spectra
• Redshift
• Doppler spectroscopy