The Sun is just one of many stars in the universe, hidden mysteries waiting for people to discover.
Every star whose human eyes can see in the sky is bigger and brighter than the Sun many times. Of the 50 brightest stars humans see with the naked eye on Earth, the star with the lowest brightness is Alpha Centauri. However, it is still 1.5 times brighter than the Sun and is not easily visible in the northern hemisphere.
On nights without the moon or any other light source around, a person with good vision sees about 2,000 - 2,500 stars at the same time. So if someone says to see millions of stars in the sky, that's just an exaggeration.
The colors of the star are often ranked in order of low to high temperature, which is red, orange, yellow, white, blue.(Artwork: NASA)
In fact, the star changes color when its temperature changes. Red represents the lowest temperature at which the star can glow in the visible spectrum. The hotter stars emit white light, the blue star has the hottest temperature.
Black objects are objects that absorb 100% of all electromagnetic radiation (light, radio waves .) when shining on it. In the case of the star, it absorbs all incoming radiation energy, and emits radiation into the space more than the amount of absorption many times. Therefore, they are black objects that emit strong light. The black object is more perfect than the black hole, but it seems really black and does not emit light.
Astronomers do not observe the green in any star, except the optical effect due to the telescope, or the view of the observer and the level of contrast. The star that emits a spectrum including green, but connects the eye - the human brain blends colors together in a way that rarely produces green. It is mixed with many other colors and the star appears white. Common colors in the order of low to high temperature are red, orange, yellow, white, blue.
The Sun has a surface temperature of more than 5,800 degrees Celsius , which corresponds to a continental wavelength (about 500 nanometers). However, when the human eye observes colors, the Sun now appears white or even yellowish white.
The Sun is just one of many stars in the universe.(Photo: ShutterStock)
Stars produce energy by maintaining and synthesizing hydrogen including dwarfs, massive stars and super-massive stars. Large stars and supernovae represent the final stage of the star, while the majority of smaller stars belong to the evolutionary maturity stage called dwarfs . The Sun is a dwarf, sometimes called " dwarf gold".
The stars look bright, especially when they appear near the horizon. When light from a star passes through the turbulent atmosphere of the Earth, it must penetrate through many layers of different air so it changes in color and light intensity, making them seem to glow. This phenomenon does not happen if we look at the star above the Earth's atmosphere.
On the beautiful night, we can see the Deneb star in the constellation Cygnus , about 32 million billion km away. This is the most visible star in the sky on autumn night, winter everywhere in the northern hemisphere.