Type G is the yellow star with spectral type G, and neutral metal wire is dominant.
The hydrogen line becomes weak, the metal line strengthens, and the ionized calcium line is very strong and wide. Such as the sun, alpha Auriga (middle name Capella).
The spectral characteristics are that the H and K lines of ionized calcium are extremely strong, and the surface temperature is 5000-6000 ℃.
G star The main features of the main sequence star are:
① fixed star He spent most of his life in the main sequence star stage, accounting for about 90% of his "life span", which is also his most stable period. ② The spectrum of the main sequence stars includes the strong luminosity O type Type B star, via type A Type F G stars, to K stars of weak luminosity M-star. The surface temperature decreases from 40000K to 2600K.
③ The energy source of the main sequence star is mainly from hydrogen to helium Thermonuclear reaction 。 ④ The mass of main sequence stars is closely related to their lifetime. The greater the mass, the faster the hydrogen consumption and the shorter the service life; The smaller the mass, the slower the hydrogen consumption and the longer the service life. For example, stars with 32 times the mass of the sun can only "survive" for millions of years, and the sun can exist for more than 10 billion years, while stars with only 7% of the mass of the sun can enjoy trillions of years of "longevity". [1]
type | temperature | Agreed colors | Color seen | quality | radius | brightness | Hydrogen line | |
|---|
O | 30000 – more | blue | blue | 20~M☉ | 30 R☉ | 1000000L☉ | weak | zero point zero one |
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| 10,000–30,000 K | Blue to bluish white | blue and white color | 5~20 M☉ | 8 R☉ | 10000 L☉ | commonly | zero point zero two |
|---|
| 7,500–10,000 K | white | white | 2~5 M☉ | 4 R☉ | 100 L☉ | strong | 0.6% |
|---|
| 6,000–7,500 K | Pale yellow white | white | 1.2~2M☉ | 1.4 R☉ | 5 L☉ | commonly | 2% |
|---|
| 5,000–6,000 K | yellow | Pale yellow white | 0.8~1.2 M☉ | 1.1 R☉ | 1.1 L☉ | weak | 3% |
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| 3,500–5,000 K | orange | Yellow orange | 0.4~0.8 M☉ | 0.5 R☉ | 0.01 L☉ | Very weak | 8% |
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| 2,000–3,500 K | gules | Orange red | <0.4 M☉ | 0.1 R☉ | 0.0001 L☉ | Very weak | 82% |
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