We know that by studying the spectrum, an astronomer can tell you what a star billions of miles away is made of and the elements that prevent it from exploding, as well as the temperature of the star and whether it is moving towards or away from Earth!
What information does the spectrum provide us about the universe?
The spectrum is made up of the lines that are formed when white light is bent, such as when it passes through a prism. There are hundreds of parallel lines all across the spectrum, in addition to the color shadings. In honor of their inventor, they are known as Fraunhofer lines.
Each chemical element in a gaseous or vapor state has its own pattern of lines in the spectrum. The lines represent the colors that the element absorbs from the light when heated to make it glow. This means that a scientist can determine what materials are present in any substance, no matter how distantly related it is. Each element has its own “dark line” or absorption spectrum that is distinct from those of other elements. A physicist can tell what a material is by simply comparing its spectrum to the spectra of elements. To put it another way, each element leaves its mark.
Light patterns can be used to detect fingerprints. Because temperature causes an element’s line positions in the spectrum to change, astronomers can learn a lot about the temperature of stars billions of miles away. Lines in the spectrum shift toward the violet end of the spectrum as a star moves toward us. When a star moves away, the lines shift toward the band’s red end. Scientists estimate that some stars are moving through space at a rate of 150 miles per second based on the amount of shift or displacement.
The Earth is four and a half light-years away from the nearest star. A light-year is approximately six million million miles. 6000,000,000 kilometers! Now, if the stars are this far away, how can we know how big they are, what they’re made of, and so on?
How are Stars studied?
Today, astronomers can study the motions, brightness, color, temperatures, and composition of stars using a variety of special instruments. The first is the camera, which is used to create permanent records of the stars seen. The spectrograph is another type of instrument. This is used to photograph the spectra of stars or the light rays that emanate from them. Astronomers have learned the majority of what they know about stars, including what they are made of, their temperatures, and the speeds at which they move, thanks to the spectrograph.
One star’s spectrum may be similar to that of other stars. The color of the stars in each spectral class is discovered to be the same. Blue to red are the predominant colors. In the middle of the range, our sun is a yellow star. Colors in the spectrum can also be used to determine the temperature of a star. The blue stars are massive, hot, and brilliant, with temperatures reaching 25,000 degrees or higher. Red stars are relatively cool, with surface temperatures of 1,600 degrees Fahrenheit or less. Astronomers are trying to figure out what chemical elements are in the stars.
What is a Star made up of?
All of the elements found in stars are also found on Earth, but stars are essentially balls of very hot gas, primarily hydrogen and helium. Astronomers also use special telescopes that can photograph large areas of the sky. The radio telescope is yet another type of instrument. This device includes a large antenna, a receiver, and a registering metre. This instrument measures the amplitude of radio waves emitted by stars and planets. So, as you can see, we can overcome great distances and learn a lot about the stars using a variety of instruments.
Do you ever get the impression that when you look up at the stars, you can trace out squares, letters, and other familiar figures?
People used to do this in almost every part of the world.
It is not always easy to see the figures that inspired the names in the sky the figures that suggest the names. So, don’t expect the constellations to actually have the outlines that the names suggest. The Greek astronomers named 48 constellations, and 40 more have been named since then, for a total of 88. Of course, not all of the constellations are visible from every location on Earth. Some are in the Southern Hemisphere’s skies; others are in the Northern Hemisphere’s skies. As the earth orbits the sun, new star clusters appear above the horizon. The circumpolar constellations, which appear to revolve around the North Star, are visible all year. There are also constellations that only appear in the winter, spring, summer, or autumn.