There area unit over a hundred billion stars in our galaxy. concerning 1 Chronicles of them area unit listed in catalogues, and also the rest area unit anonymous and aren't even counted. A star enclosed within the catalog receives a private designation: typically it's either a serial variety or a mixture of stars' coordinates. however take issueent|in several|in numerous} catalogues these numbers will differ. There aren't any official documents regulation the names of stars, however there's a convention, that is supported by astronomers once drawing up maps and atlases of the sky. (We omit here the subject of commerce star names, assured that our reader clearly understands the impurities of this "business".)
What's their name?
However, all the bright stars and even many weak ones have their own names except for scientific designations; these names were given to them in ancient times. Many of the names of stars currently in use, such as Aldebaran, Algol, Deneb, Rigel, are of Arab origin, while others come from the Greco-Roman tradition. Nowadays, an astronomer knows about three hundred historical names of stars. These are navigation stars, which have long been used for orientation by travelers and hunters. Often these are the names of the parts of those figures that gave the name to the whole constellation: Betelgeuse (in the constellation Orion) - "giant's shoulder" or "giant's armpit", Denebola (in the constellation Leo) - "lion's tail", Algenib and Markab (in Pegasus) - it's "wing" and "saddle", Fomalgaut (in South Fish) - "fish's mouth", Achernar (in Eridan) - "end of the river", and so on. In fact, it is a translation into Arabic of the star's place in the star catalog included by Ptolemy in his "Almagest". Of course, different peoples have different names for the same star: for example, Orion's "shoulder" - Betelgeuse - the Bushmen's "Female Antelope".
Having started a detailed study of the sky at the end of the 16th century, astronomers faced the need to have designations for all-stars, without exception, visible to the naked eye, and later - in the telescope. In the beautifully illustrated "Uranometry" (1603) by Johann Bayer (1572-1625), where the constellations and the legendary figures associated with their names are depicted, the stars were firstly marked by lowercase (small) letters of the Greek alphabet in approximately the descending order of their shine: α - the brightest star of the constellation, β - the second brightest, etc. If the constellation was rich in stars and 24 letters of the Greek alphabet were missing, Bayer used the Latin alphabet: first all the lower case letters, and if they were missing, then the capital letters, but no further than Q. The full designation of the star in the system of Bayer consists of a letter and the Latin name of the constellation. For example, Sirius, the brightest star of the Canis Major, is denoted as α Canis Major, or abbreviated α CMA; Algolus, the second brightest star in Perseus, is denoted as β Persei, or β Per.
The evolution of the stars
Later, John Flemstide (1646 - 1719), the first Royal Astronomer of England, who was engaged in determining the exact coordinates of the stars, introduced a system of their designations, not related to the shine. In each constellation, he marked the stars with numbers in the order of increasing their direct ascent, i.e. in the order in which they cross the meridian of heaven. Thus, Arthur, also known as α Bootis, is indicated by Flemistid as 16 Bootis. Modern star charts usually bear the ancient names of the bright stars (Sirius, Canopus, ...) and the Greek letters in Bayer's system; Bayer's designations are rarely used in Latin letters. The rest of the less bright stars are indicated by numbers in the Flemistide system.
Of particular interest when studying the evolution of stars are variable stars that change the stars, change their luster over time. For them, a special designation system is adopted, the standard of which is set by the "Common Catalogue of Variable Stars". Variable stars are designated by Latin capital letters R to Z, and then by combinations of each of these letters with each of the following RR to ZZ, and then combinations of all letters from A to Q with each of the following, from AA to QZ are used (the letter J is excluded from all combinations, which is easily confused with the letter I). The number of such letter combinations is 334. Therefore, if a constellation has a larger number of variable stars, they are indicated by the letter V (from variable) and the serial number starting from 335. To each designation, the three-letter designation of a constellation is added, for example, R CrB, S Car, RT Per, FU Ori, V557 Sgr, etc. The designations in this system are usually given only to variable stars of our galaxy. Bright variables from among the stars designated by Greek letters (by Bayer), other designations do not receive.
The flashes of new and supernovae
A special group of variable stars is represented, conditionally speaking, by variables once - flashes of new and supernovae (although new ones also have recurrent flashes). When these phenomena are discussed impersonally, the terms "new" and "supernova" are written with a small letter: for example, in 1975 there was an outbreak of a new one in the constellation Swan. But these words are written with a capital letter when referring to a specific event (or the star itself): New Swan 1975 (Nova Cyg 1975, N Cyg 1975), Supernova 1987A (Supernova 1987A, SN 1987A).
As the catalog of stars containing data on fainter stars is published in greater depths, new designation systems adopted in each of these catalogs are regularly introduced into scientific practice. Therefore, a very serious problem is the cross-identification of stars in different catalogues: one and the same star may have dozens of different designations. Special databases are being created to facilitate the search for information about the star by its various designations; the most complete of them are maintained at the Astronomical Data Center in Strasbourg.
The tradition of including in the name of the star the name of the constellation in which it is located potentially carries some inconvenience. We already know that the stars cross the boundaries of the constellations as a result of their own movements. For example, ρ The eagle is now to be searched in the constellation of Dolphin. Over time, such confusion will only increase.