Have you ever wondered how astronomers know what stars are made up of just from planet earth? Stars like our own sun are million miles away from us, we don't have that advanced technology that we can go there and check what is the basic structure of stars, its mass and its temperature etc. So how astromers study them from earth? Well in this blog I'm going to explain you how just by using simple techinque they study them. How the spectroscope works? When a material is heated to incandescence it emits light that is characteristic of the atomic makeup of the material. Particular light frequencies give rise to sharply defined bands on the scale which can be thought of as fingerprints. For example, the element sodium has a very characteristic double yellow band known as the Sodium D-lines at 588.9950 and 589.5924 nanometers, the color of which will be familiar to anyone who has seen a low pressure sodium vapor lamp. Using a spectroscope you can see that a single color of light is really comprised of a combination of colors, called a spectrum. A spectroscope enables you to see and compare the spectra produced by different light sources. It is the most fascinating part of the modern astronomy because it enables us to tell about the nature of the object in that universe in much detail without going there and touching them. In a spectrum, patterns of bright or dark areas, or lines, indicate the emission of absorption of light by particular atoms and molecules present in stars and nebulae. By studying the patterns, widths, strengths and positions of these lines we can also determine:
Here is the example of few spectra emitted by atoms. Argon Mercury Hydrogen Helium Making a spectroscope is easy: WHAT YOU NEED…. · Cereal box or other similar shaped box · Tape · Pencil or Pen · DVD or CD · Knife or scissors Instruction: · Cut slit into the box at about 30 degrees at the bottom of the box and slide the shiny surface of the cd into the slit you just made . · Make another slit at the opposite side of the CD. · The light will enter into the box through the slit and will reflect off the cd. · Now to see the light make a rectangular window in the top of box. Using a pen or pencil, draw a rectangle at one end of the cereal box. This hole will be for the diffraction grating. Using the knife or scissors, cut around the rectangle. Kids, please ask parents for help with the knife. · Congratulations, you've successfully created a spectroscope!
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