Algol, in astronomy

Algol (ăl`gŏl), famous variable star variable star, star that varies, either periodically or irregularly, in the intensity of the light it emits. Other physical changes are usually correlated with the fluctuations in brightness, such as pulsations in size, ejection of matter, and changes in spectral
..... Click the link for more information. in the constellation Perseus Perseus, in astronomy, northern constellation lying E of Cassiopeia and N of Taurus. It contains the bright star Mirfak (Alpha Persei) and Algol (Beta Persei), a visible variable star of the type known as an eclipsing variable.
..... Click the link for more information. ; Bayer designation β Persei; 1992 position R.A. 3^h07.7^m, Dec. +40°55'. Algol's variation in apparent magnitude magnitude, in astronomy, measure of the brightness of a star or other celestial object. The stars cataloged by Ptolemy (2d cent. A.D.), all visible with the unaided eye, were ranked on a brightness scale such that the brightest stars were of 1st magnitude and the
..... Click the link for more information. , from 2.06 to 3.28, is due to the fact that it is an eclipsing binary star binary star or binary system, pair of stars that are held together by their mutual gravitational attraction and revolve about their common center of mass.
..... Click the link for more information. , with one component revolving about the other with a period of 2 days, 20 hr, 49 min. Because the plane of revolution is almost parallel to the line of sight, the star dims noticeably when the dimmer component passes in front of, or eclipses, the brighter component, and dims again very slightly when the brighter component eclipses the dimmer one (see eclipse eclipse (ēklĭps`, ĭ–) [Gr.
..... Click the link for more information. ); the primary minimum, when the brighter component is eclipsed, lasts about 10 hr. Algol is of spectral class spectral class, in astronomy, a classification of the stars by their spectrum and luminosity . In 1885, E. C. Pickering began the first extensive attempt to classify the stars spectroscopically.
..... Click the link for more information. B8 V and is about 105 light-years from the earth. The name Algol comes from the Arabic Ras al Ghul, which means "demon's head," and the star is sometimes called the Demon Star.

ALGOL, computer language

ALGOL: see programming language programming language, syntax, grammar, and symbols or words used to give instructions to a computer .

Development of Low-Level Languages

All computers operate by following machine language programs, a long sequence of instructions called machine code
..... Click the link for more information. .

ALGOL

High-level algebraic computer programming language developed in the late 1950s as an international language for the expression of algorithms (its name is derived from ALGOrithmic Language) between humans as well as between humans and machines. Used especially in mathematical and scientific applications, ALGOL was more popular in Europe than in the U.S., but it was an important precursor of Pascal and it influenced the development of C language.

(ALGOrithmic Language) A high-level compiler language that was developed as an international language for the expression of algorithms between people and between people and machines. ALGOL-60 (1960) was simple and widely used in Europe. ALGOL-68 (1968) was more complicated and scarcely used, but was the inspiration for Pascal.

The following example changes Fahrenheit to Celsius:

 fahrenheit
 begin
   real fahr;
   print ("Enter Fahrenheit ");
   read (fahr);
   print ("Celsius is ", (fahr-32.0) * 5.0/9.0);
 end
 finish

ALGOL - ALGOL 60