Beta Scorpii (β Sco / β Scorpii) is a star system in the constellation Scorpius. It also has the traditional names Acrab, Akrab or El Acrab, as well as Graffias, a name it shares with Xi Scorpii. In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... The J2000. ... -1... Scorpius (, and Latin for scorpion) is one of the constellations of the zodiac. ... Right ascension (RA; symbol α: Greek letter alpha) is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. ... In astronomy, declination (dec) is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. ... The apparent magnitude (m) of a star, planet or other heavenly body is a measure of its apparent brightness; that is, the amount of light received from the object. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequenly refined in terms of other characteristics. ... In astronomy, color index is a simple numerical expression that determines the color of an object. ... In astronomy, color index is a simple numerical expression that determines the color of an object. ... Most stars are of nearly constant luminosity. ... Astrometry is a part of astronomy and deals with the positions of stars and other celestial bodies, their distances and movements. ... Radial velocity is the velocity of an object in the direction of the line of sight. ... kilometre per second is an SI derived unit of both speed (scalar) and velocity (vector), signified by the symbol km/s or km s-1. ... The proper motion of a star is the motion of the position of the star in the sky (the change in direction in which we see it, as opposed to the radial velocity) after eliminating the improper motions of the stars, which affect their measured coordinates but are not real... A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... Parallax (Greek: παραλλαγή (parallagé) = alteration) is the change of angular position of two stationary points relative to each other as seen by an observer, due to the motion of said observer. ... personal space, proxemics. ... A light year, abbreviated ly, is the distance light travels in one year: roughly 9. ... The parsec (symbol pc) is a unit of length used in astronomy. ... In astronomy, absolute magnitude is the apparent magnitude, m, an object would have if it were at a standardized distance away. ... Mass is a property of physical objects that, roughly speaking, measures the amount of matter they contain. ... The Sun is the star at the centre of our Solar system. ... In classical geometry, a radius of a circle or sphere is any line segment with one endpoint on the circle (i. ... The Sun is the star at the centre of our Solar system. ... // In General Physics In general physics, luminosity (more properly called luminance) is the density of luminous intensity in a given direction. ... The Sun is the star at the centre of our Solar system. ... Temperature is the physical property of a system which underlies the common notions of hot and cold; the material with the higher temperature is said to be hotter. ... The title of this article is incorrect due to technical limitations. ... The title of this article is incorrect due to technical limitations. ... In astronomy, the metallicity of an object is the proportion of its matter made up of elements other than hydrogen and helium. ... In astronomy, a rotation period is the time an astronomical object takes to complete one revolution around its rotation axis. ... Look up Age on Wiktionary, the free dictionary Age may refer to: The length of time that a person has lived, reckoned from date of birth in most cultures; see also: ageing, for the social, cultural, and economic factors of age and ageing. ... A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... In astronomy, many stars are referred to simply by catalogue numbers. ... In astronomy, many stars are referred to simply by catalogue numbers. ... The Henry Draper Catalogue is an astronomy catalogue with astrometric and spectroscopic data about more than 225,000 stars. ... In astronomy, many stars are referred to simply by catalogue numbers. ... In astronomy, many stars are referred to simply by catalogue numbers. ... In astronomy, many stars are referred to simply by catalogue numbers. ... In astronomy, many stars are referred to simply by catalogue numbers. ... A star system or stellar system is a group of stars (and possibly smaller bodies such as planets or asteroids) that orbit one another (a system with planetary bodies orbiting stars, are referred to as solar systems or planetary systems). ... -1... Scorpius (, and Latin for scorpion) is one of the constellations of the zodiac. ...

Observed through a small telescope, Beta Scorpii is found to be a binary star with a separation between the two components of 14 arcseconds, putting them at least 2200 Astronomical Units (AU) apart. They are both hot, B-class stars at least 10 times as massive as our own Sun, and will have a short lives. In fact, both are expected to end their stellar evolution in massive supernovae. A binary star system consists of two stars both orbiting around their barycenter. ... A second of arc or arcsecond is a unit of angular measurement which comprises one-sixtieth of an arcminute, or 1/3600 of a degree of arc or 1/1296000 ≈ 7. ... The astronomical unit (AU or au or a. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequenly refined in terms of other characteristics. ... The Sun is the star at the centre of our Solar system. ... In astronomy, stellar evolution is the sequence of changes that a star undergoes during its lifetime, the millions or billions of years during which it emits light and heat. ... Remnant of Keplers Supernova, SN 1604. ...

Beta-1 Scorpii, the brighter of the pair, has another companion 0.5 arcseconds, or about 80 AU, distant. Furthermore, both Beta-1 Scorpii and Beta-2 Scorpii, the two hot, B-class stars, are themselves thought to be spectroscopic binaries, brining the total number of stars in the system to five. A second of arc or arcsecond is a unit of angular measurement which comprises one-sixtieth of an arcminute, or 1/3600 of a degree of arc or 1/1296000 ≈ 7. ... A spectroscopic binary star is a binary star which cannot be resolved as a visual binary, even with telescopes of the highest existing resolving power. ...

Because it is close to the ecliptic, Beta Scorpii can be occulted by the Moon and, very rarely, by planets. The last occultation by a planet took place on 13 May 1971, by Jupiter. The plane of the Ecliptic is well seen in this picture from the 1994 lunar prospecting Clementine spacecraft. ... In this July, 1997 still frame captured from video, the bright star Aldebaran has just reappeared on the dark limb of the waning crescent moon in this predawn occultation. ... Crust composition Oxygen 43% Silicon 21% Aluminium 10% Calcium 9% Iron 9% Magnesium 5% Titanium 2% Nickel 0. ... A planet in common parlance is a large object in orbit around a star that is not a star itself. ... In this July, 1997 still frame captured from video, the bright star Aldebaran has just reappeared on the dark limb of the waning crescent moon in this predawn occultation. ... May 13 is the 133rd day of the year in the Gregorian Calendar (134th in leap years). ... 1971 is a common year starting on Friday (click for link to calendar). ... Atmospheric characteristics Atmospheric pressure 70 kPa Hydrogen ~86% Helium ~14% Methane 0. ...