Our Sun is a pale yellow star. Between them, in the middle of the constellation, is a bright orange star.
Color differences stars
The differences in the color of the stars are explained by the fact that the stars have different temperatures. That is why this is happening. Light is wave radiation. The distance between the crests of one wave is called its length. The waves of light are very short. How much? Try to divide an inch into 250,000 equal parts (1 inch equals 2.54 centimeters). Several of these parts will make up the light wavelength.
Despite such an insignificant length of the light wave, the slightest difference between the sizes of light waves dramatically changes the color of the picture that we observe. This is due to the fact that light waves of different lengths are perceived by us as different colors. For example, the wavelength of red is one and a half times greater than the wavelength of blue. White color is a ray consisting of photons of light waves of different lengths, that is, from rays of different colors.
From everyday experience, we know that the color of bodies depends on their temperature. Put an iron poker in the fire. When heated, it first turns red. Then she blushes even more. If the poker could be heated even more without melting it, then it would turn from red to orange, then to yellow, then to white and finally to blue and white.
The sun is a yellow star. The temperature on its surface is 5,500 degrees Celsius. The temperature on the surface of the hottest blue star exceeds 33,000 degrees.
Physical laws of color and temperature
Scientists have formulated physical laws that bind color and temperature.The hotter the body, the greater the radiation energy from its surface and the shorter the length of the emitted waves. Blue has a shorter wavelength than red. Therefore, if the body emits in the blue wavelength range, then it is hotter than the body that emits red light. Atoms of the hot gases of stars emit particles called photons. The hotter the gas, the higher the photon energy and the shorter their wave.
Therefore, the hottest new stars emit in the blue - white range. As their nuclear fuel is consumed, the stars cool. Therefore, old, cooling stars emit in the red spectrum. Middle-aged stars, such as the Sun, emit in the yellow range.
Our Sun is 149 million kilometers away from Earth, so we clearly see its color. Other stars are trillions of kilometers away from us. Even with the help of powerful telescopes, we cannot say with certainty what color they are. To clarify this issue, scientists transmit light from stars through a special device - a spectrograph. With its help, you can identify the spectral composition of starlight.
Star age by her color
Astronomers determine the color of a star by the color of the most intense radiation in its spectrum. Knowing the color of the star, using simple mathematical formulas, you can calculate the surface temperature of the star. And by temperature, you can judge her age.
