Are stars light sources?

Stars are not necessarily light sources.

First of all, the stars

1, star, Chinese word, pinyin is fán xρng, defined as lush stars, referring to many stars; Source: One of Fu Xuan's miscellaneous poems: "The stars are in accordance with the blue sky, each leaving a line." In the Song Dynasty, Ceng Gong wrote a litchi poem: "Who can be as powerful as an ox, only after picking the stars?" He Jingming's lotus poem in Ming Dynasty: "Show a rosy face and the stars are shining."

2. Qing Shenfu's Six Chapters of a Floating Life: "Those who twinkle like stars in the sky are also the lights of wine boats." Mao Dun's Midnight Seventeen: "The deck of the ship is decorated with small red and green electric lights, which compete with the stars in the sky on that cool night."

Second, the light source

1, light source is a physical term, which can emit electromagnetic waves in a certain wavelength range (including visible light and invisible light such as ultraviolet light, infrared light and X-ray). Usually refers to an object that can emit visible light. Light sources can be divided into natural light sources (natural light sources) and artificial light sources. The sun, turned on lights, burning candles, etc. They are all light sources.

2. In physics, it refers to an object that can emit electromagnetic waves in a certain wavelength range (including visible light and ultraviolet light, infrared light, X-rays and other invisible light). Usually refers to a luminous body that can emit visible light. But things like the surface of the moon and the desktop depend on them to reflect external light, so that people can see them. Such a reflector cannot be called a light source or an illuminator.

In our daily life, we can't live without visible light. Visible and invisible light sources are also widely used in industry, agriculture, medicine and national defense modernization. An object that can emit light by itself and is emitting light is called a light source. Light sources can be divided into natural light sources, natural light sources and artificial light sources.

Third, the mode of production

1, thermal effect: sunlight is a good example, except candles, which will change color with the change of temperature; Atomic transition: the fluorescent substance coated on the inner wall of fluorescent tube is excited by electromagnetic wave energy to produce light. In addition, the principle of neon lights is the same. Atomic luminescence has its own characteristic spectral lines. Scientists often use this principle to determine the types of elements.

2. Radiative luminescence: For example, synchrotron emits synchrotron radiation when it works, and it also carries powerful energy. In addition, the pale blue shimmer (Cherenkov radiation) emitted by atomic furnaces (nuclear reactors) also belongs to this category.

3. The so-called "Cherenkov radiation" means that the speed of charged particles in the medium may exceed the speed of light, in which case radiation will occur, similar to "sonic boom".