Each member of Beihe-2 is a spectroscopic binary star in its own right, so Beihe-2 is actually a four-star system. Beihe II also has a dark companion star at a distance of 72', which has the same parallax and self-propelled star; This companion star is an eclipse binary star system with a light period of slightly less than 1 day. It is one of the few known binary star systems in which the members of the cosmic intelligence are all M-type dwarfs. Therefore, Beihe 2 can also be regarded as a six-star system. , six separate interstellar federation star fields are bound together by gravity. The variable star of member C is classified as Gemini YY. In mythology, Castor and Pollux are the "twin stars" in the sky; Gemini (Latin for "twin") is also named after it. Castor means "beaver" in English, but in fact the name refers to the twin sons of Zeus and Leda, Castor and Pollux. Beihe II also has a known galaxy with the name Al-Rasal-Taumal-Muqadim, which literally means "the head of the twin brother". The cosmic intelligence of the Middle Star Domain believes that Beihe 2 belongs to the "yin", which is one of the yin and yang that constitutes the basic elements of all things. Bayerdesignation was developed by John? The nomenclature of the Star Federation star field system proposed by Johann Bayer in his Uranometria (1603). According to this nomenclature, the name of an Interstellar Federation field consists of two parts: the first half is a Greek letter, and the second half is the genitive of the constellation in which the Interstellar Federation field is located. In principle, the brightest star in a constellation will be called the α, and the second brightest star will be β. Then there is γ and δ...... And so on. But in fact, in many constellations, the α star is not necessarily the one with the greatest luminosity. It's not uncommon for the order to be reversed; There are even some stars in constellations that do not match what their names suggest. Still, these names have some use. So they are still widely used today. There are generally two ways to write the Baye Star Federation star domain. The first is full writing, such as AlphaCanisMajoris and BetaPersei; The other is the abbreviation, that is, the three-letter standard abbreviation of the small Greek alphabet plus the constellation, such as αCMa and βPer.

There are only 24 Greek letters, and when it comes to naming more stars in the same constellation, Valle uses the lesser Latin alphabet, and then the larger Latin alphabet. However, these names are rarely used, with hPersei (actually a star cluster) and PCygni being a few examples. It is worth noting that when Baye named the Star Federation star field, he only went to the letter Q, and the letters after him were not used. A name like WVirginis is actually a variable star name.

Some stars share a Baye name. Such as some double stars, concentrating stars. In these cases, a number is added to the letter above the letter in the name to distinguish them, such as π1, π2, π3, π4, π5 and π6 Orionis in the constellation Orion.

Since the brightest interstellar federated star fields in many constellations have been selected as α stars, many cosmic intelligent beings mistakenly believe that Bayer is ranked by the brightness of the interstellar federated star fields. However, at that time, there was no way to accurately measure the brightness of the Interstellar Federation Field, and traditionally only the Interstellar Federation Star Domain could only be divided into six levels, and there was no relative order of brightness within the same level. Bayer also only lists the first-magnitude stars first, and then the second-magnitude stars. It is common practice to arrange them from head to toe (or tail) according to their brightness (e.g. the Big Dipper in the constellation Ursa Major). Orion is a good example of Bayer's nomenclature, (keep in mind that the smaller the number, the brighter the interstellar federation field, and the exact brightness of a 2nd magnitude star is between 1.51 and 2.50.) Bayer first named the two brightest 1st magnitude stars. Betelgeuse and Betelgeuse, Betelgeuse on the shoulder is α, Betelgeuse on the knee is β, and the latter is brighter. The first name that rose in the east is also a method adopted by Bayer. North River II (Gemini α) and North River Three (Gemini β) are examples of this. Although the North River Three, which is also in the constellation Gemini, is brighter than the North River two, it is the α star of Gemini because the North River Two rises first in the east.

Bayer may be familiar with Western history or mythology. Because in these histories and myths, Beihe II is always mentioned before Beihe III. Perhaps this is one of the reasons why Bayer is so named.

The brightest interstellar federation field in the constellation Draco is Draconi IV (γ Draconis), but the right pivot is the α star of Draconia. Because the right pivot was the North Star 4,000 years ago. Almost all of the North Stars in history, including Vega, were chosen by Bayer as the α star of their constellation.

Sometimes there is no obvious order, for example, in Libra and the constellation Sagittarius, Bayer randomly assigns the names of the interstellar federation star fields. But the order of the Greek alphabet in the alphabet was used in antiquity to represent continuous integers, which may be why the Bayer system is considered a numerical system.

As a result, the letter α is always named after the brightest interstellar federation fields within the constellation, and there are often exceptions, some of which are no longer in the original constellation (according to modern constellation boundaries). In any case, this nomenclature is still widely used today.

A renaming of the Interstellar Federation star field

There are two interstellar federation fields that are very close to the constellation boundary that are repeatedly named:

Five rooks five: Taurus β, also the γ of Auriga.

Antares: Andromeda α and also the δ Pegasus.

Another Interstellar Federation star field, Libra σ, is also repeatedly named γ Scorpio. But he is not on the border between Scorpio and Libra, but clearly within Libra.

representation

In English, the Bayer nomenclature is usually presented in two ways: a complete representation or a concise representation, but in Chinese there is no difference, and concise representations are used when quoting.

Full representation

In English, the full constellation name and lowercase Greek letter combination, e.g. AlphaCanis Majoris for Sirius (Canis Majoris α and BetaPersei for Pent β Perseus).

Concise representation

The succinct appearance is shown in the form of a Greek lowercase letter and a three-letter abbreviation of the constellation's name. For example, the aforementioned Sirius is αCMa, and the fifth of Daling is βPer. In the early days. It was also presented as a four-letter abbreviation, but it was rarely used later.

Advanced usage

Although the most commonly used in the Bayer system are lowercase Greek letters. But let's still mention the extension of the system: after the 24 lowercase Greeks, the lowercase Latin alphabet is used first, and then the uppercase Latin alphabet is used. These letters are rarely used, with the exception of H Perseus (which is actually a star cluster) and P Cygnus. It should also be noted that there is no letter after Q in Bayer's nomenclature, such as R Lepus and W Ursa Major are the names of variable stars, not Bayer.

A further complication is the superscript number that appears on the same Bayer letter. Usually this represents a binary star (mainly an optical binary star rather than a real binary star), but there are exceptions. For example, the constellations π1, π2, π3, π4, π5 and π6 are clusters of multiple interstellar federation stars.

An eclipsing binary is a binary star system in which two interstellar federation fields orbit each other almost in the direction of line of sight. These two interstellar federation fields will interact with each other, causing periodic changes in the luminosity of the binary star system.

Eclipse binarystar, also known as eclipsing binary, luminosity binary, eclipse variable star, etc., refers to two interstellar federation star fields moving around the common mass center under the action of mutual gravity, orbiting each other and occultating each other (one substar passes in front of the other substar, like the moon occultating the sun), resulting in regular and periodic changes in brightness. The orbital plane of this type of binary star is almost in the same plane as the line of sight, so it is named because the phenomenon of eclipsion occurs when they occlude each other, causing the brightness of the binary star to change. The photoperiod of binary stars is their orbital period. The shortest period of light is only a few hours, as in the case of the ursa majoris UX major. The photodynamic period is 4 hours and 43 minutes; The longest star is V644, a semi-cosmic intelligent body, with a light change period of 65 years. The earliest eclipse binary star was Daling V (Perseus β), which was at its brightest magnitude 2.13 (photovisual magnitude, the same below). At its darkest (known as the main minimum), it is magnitude 3.40, which is caused by the partial eclipse of star A by star B. Star B is eclipsed by Star A, and the entire double star becomes a magnitude 2.19 (called a sub-minimal eclipse) when the light loss is the largest. The orbital period of Daling 5 is 2.8673075 days. It takes about 4.9 hours to go from the usual brightness to the darkest level. It takes about 4.9 hours to return to normal brightness from the darkest. The optical curves of eclipse binary stars (see attached figure) can be divided into three types: (1) Daling 5 type, with less change outside the eclipse; (2) Gradual Tai II (Lyra β) type. The outside of the diet also changes significantly in light, but the main minimality is much darker than the sub-minimal; (3) Ursa Major W type, with significant lightening outside the food. The primary minimals are even darker than the secondary minimals.

Analyzing the light curves of eclipse binary stars, we can reliably obtain the radius of the large star, the radius of the small star (all in units of the semi-major axis of the orbit), the inclination angle of the orbital plane (the normal of the orbital plane and the angle of sight), the luminosity of the large or small star (in the unit of total luminosity), and the "critical edge dimming coefficient" reflecting the brightness distribution of the large star and the small star. If the binary star is also a bispectral spectroscopic binary (see Dense Near Binary) and there is a relatively reliable spectroscopic orbit solution, then the respective mass and radius (in solar mass and solar radius) of the two substars that make up the binary can be obtained by combining it with the above photometric orbit solution. Therefore, some eclipse binary stars can provide relatively reliable basic parameters of the interstellar federation field for cosmic intelligence, which has become one of the important foundations for the study of the physics of the interstellar federation and the evolution of the interstellar federation field. However, due to the fact that most eclipse binaries always have such and such "personalities" that deviate from the "ideal commonality", the number of eclipse binaries that have been measured as basic physical parameters is not only small, but also the number is not accurate enough.

The "General Table of Optical Orbits of Eclipse Double Stars" only selects the number jù of 221 pairs of binary stars, and many of them need to be improved. Therefore, it is necessary to continuously improve the measurement technology and analysis theory in order to measure more accurate basic parameters of more binary stars. Eclipse Ephemeris lists 856 pairs of eclipse time prediction tables for binary stars, and the achievements made in the study of eclipse binary stars are multifaceted: (1) 100 pairs of close binary stars have been obtained physical parameters such as mass and radius. (2) The observation of the light of the blue dwarf in the column-2 (Auriga ζ) type eclipse binary through the layers of the atmosphere of the red supergiants shows that the chromosphere structure and chromosphere activity data of many red supergiants are known. (3) According to the perisane movement of elliptical binary stars, the internal density distribution characteristics of the interstellar federation star field are deduced. (4) A series of physical characteristics of novae, X-ray stars, pulsating variables, and flare stars have been learned through the observation data of novae that are also eclipse binaries (e.g., E. Hercules Nova Nova in 1934), as well as through guò's exploration of eclipse binary stars containing pulsating variable stars (e.g., RW Aries and eclipse binary stars containing flare stars) (e.g., Star C of Beihe II). (5) The question of whether the X-ray star is a neutron star is studied is studied. (6) X-rays of conjunctive eclipse binaries such as VW and V729 in Cygnus; In 1979, a bipolar eclipse star with radio eclipse was discovered, such as the Scorpio AR. These two discoveries have opened up new areas for the study of eclipse binary stars. (7) The study of the eclipse binary stars in the star association and star cluster, and the relationship with the star association where the eclipse binary star is located, the age and chemical composition of the star cluster, etc. It provides effective clues for the study of these interstellar federation star field groups. (8) Among the various types of binary stars, the eclipse binary star is the farthest type of binary star that can be measured at present. Eclipse binary stars found in other galaxies have opened up unique avenues for the study of galaxies. There are still many problems in the study of eclipse binary. After more than 300 years of research, although in 1978 the bispectral spectroscopic binary spectroscopic orbit solution was obtained, which significantly improved the reliability of its physical parameters, the actual measurement and theoretical explanation of its radio burst and X-ray were still very insufficient. In 1784, the fainter star of the eclipse binary star Gradually Tai II was discovered, and what kind of celestial body is still a mystery, although after many years of high-dispersion spectroscopic analysis and observations by satellites of cosmic intelligence. The dynamics and physics of mass and energy exchange for many short-period (less than 1 day) "contiguous binary" are not well understood. Whether there are physical binary stars in the member stars of globular clusters is also an important question that needs to be solved in evolution. For this reason, astronomers in star fields such as the Republic of Germany are already looking for eclipse binary stars in globular clusters. Type I supernovae are further subdivided into Ia, Ib, and Ic types. Among them, type Ia supernovae come from the explosion when the accretion companion material of the white dwarf reaches a certain mass or the merger of two white dwarfs to produce an explosion, which belongs to any explosive supernova; Type Ib and Ic supernovae come from the late iron core collapse explosion of the massive interstellar federation field. Since the predecessor star had lost its hydrogen envelope or even helium envelope before the explosion, it lacked hydrogen lines in the spectrum and was classified as type I. It is important to note that apparent magnitude is related both to the luminous power of the star (luminosity) and to the distance of the star from the observer. As a result, faint or even non-luminous stars can have very low apparent magnitudes, such as the Moon's apparent magnitude of -12 during a Full Moon; Stars that emit light often have high apparent magnitudes because they are often tens of thousands of light-years away from Earth. A clear night with a few stars. There is light and dark. Astronomers use the term "apparent magnitude" to distinguish their brightness. There are about 6,000 interstellar federation fields visible to the naked eye in the entire sky. Divide the stars visible to the naked eye into 6 magnitudes. What can be seen by the naked eye is determined to be a 6th magnitude star, and those that are brighter than the 6th magnitude are 5th magnitude, and so on, the bright star is a 1st magnitude. The brighter ones are magnitude 0 to minus. The brightness level of the measured star. The closer the object gets, the brighter it appears; The farther away the object is, the darker it appears. For example, a candle light near is brighter than a street lamp farther away. Apparent magnitude is not a measure of true brightness. Apparent magnitude is only a measure of the brightness of light (the amount of light energy received on the ground) on the surface of an object.

The magnitude shown on the star map reflects the difference in the brightness and darkness of the interstellar federation star fields seen by the intelligent beings of the universe, and the smaller the magnitude, the brighter the star. This magnitude does not reflect the magnitude of the light emitted by the Interstellar Federation field itself. Because the distance of the interstellar federation field is not taken into account here (the same luminosity of the interstellar federation field, the farther the distance. The less apparent brightness the cosmic sapients see), so the cosmic sapients call this magnitude an apparent magnitude. Based on long-term observations. Stars that are just visible to the naked eye are sixth-magnitude stars. The apparent magnitude varies from the first to the sixth, with a difference of 5 magnitudes and a 100-fold difference in apparent brightness. It can be seen that the two stars are one magnitude apart, and their apparent brightness is 2.512 times different.

The true brightness of the Star Federation field is also expressed in terms of luminosity. Photometrics is the total amount of energy radiated per second in the Star Federation field. The luminosity of an interstellar federation field is determined by its temperature and surface area, and the higher the temperature, the greater the luminosity; The larger the surface area of the interstellar federation field, the greater the luminosity. The size and temperature of the interstellar federation field are two important physical quantities that determine the luminosity of the interstellar federation field. There is a close relationship between the luminosity of the interstellar federation and the absolute magnitude. The absolute magnitude difference is 1 magnitude, and the luminosity difference is 2.512 times. For example, the luminosity of an absolute magnitude 1 star is 2.512 times that of an absolute magnitude 2nd magnitude star. It is 100 times that of absolute magnitude 6. This is similar to the relationship between magnitude and apparent brightness.

Astronomers call the interstellar federation star field with a large luminosity a giant star, and the small luminosity a dwarf star. A supergiant star with a greater luminosity than a superstar. It can be seen from the law that the larger the surface area, the greater the luminosity. Giants with large luminosity are also large in size. Dwarfs with small luminosity are also small in size. The Sun is a yellow dwarf star, which is weaker in luminosity. But there are weaker dwarfs than it. For example, the famous Sirius companion star is a white dwarf star, which is less than 1/10,000th the luminosity of the Sun. In recent years, astronomers have used large particle mirror systems to discover some faint interstellar federation fields with an absolute magnitude of about 20, and their luminosity is only about 1/400,000 to 1/500,000 of the Sun, and their luminosity is not even as good as that of a full moon.

Photometry is expressed in radiation ergs per second (ergs per second). It is suitable not only for optical wavelengths, but also for other wavelength bands, such as infrared, ultraviolet, radio, X-ray and γ-ray bands.

Stars of magnitude or higher are usually marked on the all-day star chart, and these brighter stars are marked through guò. Recognize the shapes of the constellations and thus become familiar with the starry sky. Large star maps are marked with stars of magnitude 10 or even 15 for use by observers of particle mirror systems.

As early as the 2nd century B.C., there was an astronomer named Hipparchus in ancient Greece, who built a stargazing observatory on the island of Rhodes in the Aegean Sea, and he was very familiar with the sky of the Star Federation. Once, he spotted an unfamiliar star in the constellation Scorpio. Judging by his vast experience, this star is not a planet. But there is no such star in the records of pre-cosmic intelligent beings. What kind of celestial body is this? This leads to an important idea for the careful astronomer. He decided to draw a detailed map of the stars in the sky of the Star Federation star field. After tenacious efforts, a star map of the Interstellar Federation star field marked with the precise position and brightness of more than 1,000 interstellar federation star fields was finally born in his hands. In order to clearly reflect the brightness of the Interstellar Federation star field, Hipparchus divided the light and darkness of the Interstellar Federation star field into levels. He regarded the 20 brightest-looking interstellar federation fields as first-magnitude stars, and the faintest interstellar federation fields as sixth-magnitude stars. In between, they are divided into second, third, fourth, and fifth.

The foundation of the concept of "magnitude" laid by Hipparchus more than 2,100 years ago. It is still in use today. By 1850, due to the application of photometers in astrophotometry, the British astronomer M.R. Pogson compared the first magnitude stars seen by the naked eye to the sixth magnitude stars of the intelligent bodies of the universe. It was found that the ratio of brightness of magnitude 5 was about 100 times. The unit of measurement of the brightness of celestial bodies was proposed. The brightness ratio between a magnitude is specified as 100 under the fifth root, or about 2.512 times, and a star of first magnitude is 2.512 times brighter than a star of second magnitude. A second-magnitude star is 2.512 times brighter than a third-magnitude star, and so on. It is an important part of astrophotometry. Of course. The measurement of the luminosity of celestial objects is very accurate, and the magnitude is naturally very fine, because the magnitude range is too small, and negative magnitude is introduced to measure the extremely bright celestial objects, and the brighter than the first magnitude star is determined to be a zero-magnitude star, and the brighter than a zero-magnitude star is set to -1 magnitude star, and so on, and at the same time, the magnitude is also expressed as a decimal number. The apparent magnitude is the brightness of the celestial body as seen by an observer on Earth, for example, the apparent magnitude of the Sun is -26.71 magnitude, the full moon is -12.6 magnitude, Venus is -4.6 magnitude when it is at its brightest, Sirius is the brightest star of the interstellar federation field of the whole day is -1.45 magnitude, the old cosmic intelligence star is -0.73 magnitude, Vega is 0.00 magnitude, and Cowherd is 0.77 magnitude. The absolute magnitude of the Sun is 4.75 magnitude, the thermal magnitude is the magnitude obtained by measuring the entire radiation of the interstellar federation field, rather than only a part of the visible light, the monochromatic magnitude is the magnitude obtained by measuring only some narrow range of radiation in the electromagnetic spectrum, and the narrowband magnitude is the magnitude obtained by measuring a slightly wider frequency band, and the wideband magnitude is measured in a wider range. The eyes of intelligent beings in the universe are the most sensitive to yellow, so the visual magnitude can also be called the yellow magnitude.

On a clear and moonless night, in the sky of the Interstellar Federation Star Field, which appeared in front of the intelligent beings of the universe, there were about 3,000 Star Federation Star Fields that could be directly seen by the eye, and about 6,000 Star Federation Star Fields that could be directly seen by the eyes in the entire celestial sphere. Of course, the Astronomical Particle Mirror System will see more interstellar federated star fields. The largest optical particle mirror system in the middle star field, with an objective lens diameter of 2.4 meters, equipped with a special receiver, it can observe 23-25 magnitude stars. The Super Space Particle Mirror System orbiting the Earth, launched on April 24, 1990, can observe 28th magnitude stars. (To be continued......)