What Is a Variable Star?
A variable star is a star whose brightness and electromagnetic radiation are unstable, often changing, and accompanied by other physical changes [1] .
- Around 1600 AD, it was first discovered that the luminosity of certain stars would change. In 1572 and 1604, there were
- Variable star A star whose brightness changes due to internal physical reasons or external geometric reasons. Although some stars have no change in brightness, other physical properties or electromagnetic radiation outside the optical band are also classified as variable stars.
- There are many types of variable stars, involving
- There are geometric reasons (such as eclipse, screen) and physical reasons (such as pulsation, burst) that cause the brightness change of stars, and both (such as eclipse plus mass communication between the two stars).
- Variable star naming refers to the methods and rules for naming variable stars.
- Variable stars are named using
- Eclipse is a binary star system, two
- A pulsating variable star is a star whose brightness changes due to pulsation. The change in the brightness of these variable stars may be due to the body of the star (its own
- Cepheid variable star (Cepheid variable star) a class of high-luminance periodic pulsating variable stars, that is, its brightness changes periodically with time. Because of typical stars
- The Taurus T-type variable star is an irregular variable star with a spectral type of G to M. The typical star is T Taurus, which was first discovered by Joey in 1945. The Taurus T-shaped variable star and the diffuse nebula form a close association and appear as a group, often forming the main members of the T-star association. Some people estimate that there are about 12,000 Taurus T-shaped variable stars within a thousand-second gap around the sun, and the total number of galaxies in the galaxy is 1 million. These variable stars all have irregular periodic light changes, or fast light changes superimposed on long-term slow light changes. The maximum amplitude is 5 magnitudes, usually 1 to 2 magnitudes. It is also found that there is also a light change in the infrared band. Their spectra are superimposed with a series of emission lines on a night-type photosphere. The strongest emission lines are the Barm line and the H and K lines of ionized calcium Ca. Ionization iron Fe, ionized titanium Ti, neutral iron Fe and neutral calcium Ca emission lines and low-excitation metal atomic lines often appear. There is an overlapping continuous emission spectrum region in the blue-violet region. In individual cases, this continuous emission is particularly strong, causing the photosphere absorption spectrum to be completely overwhelmed. In the high dispersion spectra of some bright Taurus T-type stars, most of the absorption lines have been broadened. It shows that they have a large rotation speed. Many T-shaped Taurus stars have P-shaped star bricks in Cygnus. That is, absorption lines appear at the short-wave end of the strong emission line profile, which indicates that they project material outward. The mass loss rate is estimated at 10 to 10 solar masses per year. A few T-type Taurus stars have anti-Cygnus P-type star spectra, indicating the phenomenon of material sinking inward. Some Taurus T-stars have polarizations as high as 12%. The lithium abundance of the T-shaped star of Taurus is about two orders of magnitude higher than that of the solar atmosphere, and it has infrared color residual. Radio radiation from the Taurus T star has been measured. What is the title? O Taurus T-type star is a pre-primary star in the gravitational contraction stage.
- Xinhua Online, November 20th (Reporter Zhang Jiansong) On the 20th, reporters learned from the "2009 Annual Conference of Chinese Polar Science" that China's "Small Telescope Array" installed in the A Dome A area of Antarctica Find dozens of variable stars.
- According to Zhu Zhenyu, China's Antarctic Astronomical Center, during the 24th and 25th Antarctic scientific expeditions in China, China successfully installed China's small telescope array, sodar, sky light spectrometer, sky light during the ice dome A area, the highest point of the Antarctic ice sheet Cloud measurement instrument and sub-millimeter wave telescope and other astronomical observation equipment. These devices are operating normally, and staff can monitor real-time conditions and equipment working conditions in Antarctica.
- The "China Small Telescope Array" independently developed by China is composed of four 145 mm aperture, reflecting large field of view telescopes, which can continuously observe the Antarctic zenith 20 to 25 square degrees sky area continuously for 135 days. Through observation, we have obtained the complete light change curve of a group of celestial bodies, and found dozens of variable stars. The photometric star tables and variable star tables in the celestial area have been provided to the National Observatory Data Center for download.
- According to reports, a variable star is a star with fluctuating brightness. There are many reasons for the change in the brightness of stars, so there are many types of variable stars, which involve various stages of star evolution. Strengthening research on variable stars can promote the development of the theory of stars.
- Antarctic astronomical observations also show that Antarctic Ice Dome A has the best astronomical observation conditions on the earth's ground. The 4m optical / infrared telescope installed on Ice Dome A will exceed the 10m optical telescope and 30m infrared telescope installed in Hawaii. The 15-meter terahertz telescope installed in Dome A will exceed the capacity of the 40-meter terahertz telescope installed in Chile.
- Astronomers believe that the Antarctic Ice Dome A provides an excellent observation window for astronomical research, and brings new opportunities for the study of major scientific issues such as the origin of the solar system, the early universe structure and evolution, and cosmic dark matter and dark energy.
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