In addition to being ecstatic before one of the most beautiful shows that we can contemplate on our planet, there are many questions that we ask ourselves when we see a starry sky. ¿ What are the stars ? ¿ How do stars form ? ¿ Why do stars shine ? Perhaps you have also asked yourself if the stars move or remain motionless in the heavenly vault. Join us and discover if the stars move or are fixed .
You may think that the stars are moving since you have seen a shooting star cross the night sky. But nevertheless, what we call a shooting star is not really a star and that name is inappropriate . What we see are meteors or luminous phenomena that result when a meteroid passes through our atmosphere. If you want to know more about shooting stars, in Supercurious we provide all the necessary information in the following entry: What are the shooting stars and why do we make wishes?
Are the stars moving or are they still?
In the first place, we will reveal the mystery and then we will go into the historical and specific explanations. Yes, the stars move . Although for millennia the stars were considered to be quiet At present, thanks to the modern instruments at our disposal, we know that the stars move.
The stars are a "luminous sphere of plasma that maintains its shape thanks to its own gravity". These huge celestial bodies that for us are small points of light, are many light years from Earth, except our Sun. The galaxies, of which there are billions in the universe, are composed basically of stars and in a galaxy like ours, the Milky Way, astronomers estimate that There may be about 300 billion stars. Awesome!
1. Fixed stars and wandering stars in the history of astronomy
Since humanity became sedentary and formed communities and civilizations, there are vestiges of its interest in heaven and the emergence of the astronomy . Chaldeans, Babylonians, Egyptians, Greeks, Arabs, Chinese, Hindus and also the pre-Columbian cultures were fixed in the starry sky. In all human cultures there were astronomers , since the study of the sky was a very useful tool to determine periods of time in which to carry out certain activities. The ancient greeks , to whom we owe the most accurate documented observations, distinguished between fixed stars and wandering stars and this concept of "fixed stars" was maintained until the seventeenth century.
The fixed stars were the celestial objects that seemed to stand still in relation to the other stars . Many cultures thought that they formed images in the sky that were called constellations and placed them on a celestial sphere known as the "sphere of the fixed" that circled the Earth every day. Unlike these "fixed stars", the planets and sometimes also the Sun and the Moon, constituted the "wandering stars" that were thought to revolve around our Planet. These concepts were maintained until the Copernican revolution at the end of the 16th century. That the stars move with their own motion was discovered in 1718 by Edmund Halley .
2. How do we know that the stars move?
As the stars, except the Sun, are so far away from Earth, the perception is that they remain fixed in the sky. However, it is not like that. We know that the stars move on the one hand in the set of the movement of the galaxy of which they are part, basically due to its rotation, and on the other hand for a movement of the star itself .
Edmund Halley confirmed his discovery because he was able to make precise measurements over long periods of time, something that the old astronomers could not do. To make these measurements, the position of a star is usually used in relation to a group of celestial objects that are very distant from it and that for that reason they do not appreciate their own movement. Currently, the comparison of photographs of the star in different moments is usually used having as background a large group of much more distant objects.
As a point, we should not confuse that the stars really move with the "parallax" which is an apparent, but not real movement that occurs due to the orbital movement of the Earth.
3. Movement of Rotation and Own Movement
Stars move by the rotation movement of the galaxy to which they belong. They revolve around the center of the galaxy and, for example, the Sun, it takes about 250 million years to make the complete revolution. The second movement of the stars is the movement itself that discovered Halle Y. This is measured by the change of its position in the sky and is due to a small random movement beyond the galactic rotation.
4. Barnard's star; the star with the best known own movement
The star of Barnard is the star that has greater own movement that has been observed so far. It is a star in the constellation of Ophiuchus and to observe it you have to use a telescope since at first glance it is too dim. Because of its proximity, 5.9 light years of the solar system, and favorable position has been the subject of many studies.
The star of Barnard has a movement of its own that according to scientists is equivalent to a lateral velocity relative to our line of sight of the Sun of about 90 km / s.
In addition to discovering if the stars move or are fixed, do not miss ...
Have you been interested in discovering if the stars move or are still? Then do not lose sight of the recommendations that we do next, sure you find interesting:
- The stars and the sky have inspired great minds of humanity, discover their interesting reflections in Star Phrases Y Phrases from heaven I'm sure you'll love it.
- And if you're hungry for more curiosities, check out our entries on Curiosities of the Universe Y Curiosities of the solar system . They will surprise you!
We give here our answer to whether the stars move or are fixed. As always, we will be happy to meet you in the comments. Tell us, did you know that the stars have their own movement? Do you have more information about the stars? We are waiting!