AB Doradus is a pre-main sequence trinary star system in the constellation Dorado. The primary is a flare star that shows periodic increases in activity. In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... Orion is a remarkable constellation, visible from most places on the globe at one time or another during the year. ... Other uses: dorado is used in the fisheries of some Latin American countries to denote the edible fish mahi-mahi (Coryphaena hippurus Dorado is also the name of mythical Latin American warriors. ... 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. ... // Headline text HEY!! HOW ARE YOU ALL?? Its nice of you to come read this page. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequently refined in terms of other characteristics. ... In astronomy, color index is a simple numerical expression that determines the color of an object, which in the case of a star gives its temperature. ... In astronomy, color index is a simple numerical expression that determines the color of an object, which in the case of a star gives its temperature. ... Most stars are of almost constant luminosity. ... A flare star is a variable star which can undergo unpredictable dramatic increases in brightness for a few minutes or a few hours. ... This article does not cite its references or sources. ... 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 milliarcsecond (m, mas) , or a thoundsanth of an arcsecond. ... A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... A milliarcsecond (m, mas) , or a thoundsanth of an arcsecond. ... A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... Parallax, or more accurately motion 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 an observer. ... A milliarcsecond (m, mas) , or a thoundsanth of an arcsecond. ... Distance is a numerical description of how far apart things lie. ... A light year, abbreviated ly, is the distance light travels in one year: roughly 9. ... Stellar parallax motion 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 standard luminosity distance away from us (in the absence of interstellar extinction!). It allows the overall brightnesses of objects to be compared without regard to distance. ... Mass is a property of a physical object that quantifies the amount of matter and energy it is equivalent to. ... In astronomy, the solar mass is a unit of mass used to express the mass of stars and larger objects such as galaxies. ... In classical geometry, a radius of a circle or sphere is any line segment from its center to its boundary. ... In astronomy, the solar radius is a unit of length used to express the size of stars and larger objects such as galaxies. ... Luminosity has different meanings in several different fields of science. ... The solar luminosity, , is a unit of luminosity (power emitted in the form of photons) conventionally used by astronomers to give the luminosities of stars. ... In thermodynamics, temperature is the physical property of a system that underlies the common notions of hot and cold —something that is hotter has the greater temperature. ... The kelvin (symbol: K) is the SI unit of temperature, and is one of the seven SI base units. ... In astronomy, the metallicity of an object is the proportion of its matter made up of chemical elements other than hydrogen and helium. ... Rotation of a plane, seen as the rotation of the terrain relative to the plane (exposure time 1. ... The Pleiades, an open cluster of stars in the constellation of Taurus. ... 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. ... Orion is a remarkable constellation, visible from most places on the globe at one time or another during the year. ... Other uses: dorado is used in the fisheries of some Latin American countries to denote the edible fish mahi-mahi (Coryphaena hippurus Dorado is also the name of mythical Latin American warriors. ... A flare star is a variable star which can undergo unpredictable dramatic increases in brightness for a few minutes or a few hours. ...

The primary star in this system spins at a rate 50 times that of the Sun, and consequently has a strong magnetic field.^[3] It has a greater number of star spots than does the Sun. These can cause the luminosity of the star to appear to vary over each orbital cycle. Measurements of the spin rate of this star at its equator have shown that it varies over time due to the effect of this magnetic field.^[4] Sun SPOT (Sun Small Programmable Object Technology) is a wireless sensor network (WSN) mote developed by Sun Microsystems. ...

The primary has two companions. The star AB Doradus B orbits the primary at an average distance of 135 astronomical units (AUs). AB Doradus C, is a close-in companion that orbits the primary at a distance of 2.3 AU, and has an orbital period of 11.75 years. The later star is among the lowest mass stars ever found. At an estimated mass 93 times Jupiter's, it is near the limit of 75-83 Jupiter masses below which it would be classified as a brown dwarf.^[5] The astronomical unit (AU or au or a. ... Adjective Jovian Atmospheric characteristics Atmospheric pressure 70 kPa Hydrogen ~86% Helium ~14% Methane 0. ... This brown dwarf (smaller object) orbits the star Gliese 229, which is located in the constellation Lepus about 19 light years from Earth. ...

This system is a member of the like-named AB Doradus moving group, a loose stellar association of about 30 stars that are all moving in the same general direction and having approximately the same age. ^[6] It is likely that all of these stars formed in the same giant molecular cloud. A stellar association is a very loose star cluster, looser than both open clusters and globular clusters. ... A dark nebula is a large cloud which appears as star-poor regions where the dust of interstellar medium seems to be concentrated. ...

References

1. ^ M. Jardine, C. A. Collier, J.F. Donati (2002). "The global magnetic topology of AB Doradus". Monthly Notices of the Royal Astronomical Society 333 (2): 339-346.
2. ^ K. L. Luhman, John R. Stauffer, E. E. Mamajek (2005). "The Age of AB Dor". Astrophysical Journal 628: L69-L72.
3. ^ JR Minkel (2001-12-11). Shimmying Star May Shed Light on Forces at Work in the Sun (in English). Scientific American. Retrieved on 2006-06-25.
4. ^ A. C. Cameron, J.F. Donati. Christmas Star Does the Twist (in English). PPARC. Retrieved on 2006-08-25.
5. ^ "Weighing the Smallest Stars", ESO, 2005-01-19. Retrieved on 2006-08-13.
6. ^ B. Zuckerman, I. Song, M. S. Bessell (2005). "The AB Doradus Moving Group". The Astrophysical Journal 613 (1): L65-L68.

2006 (MMVI) is a common year starting on Sunday of the Gregorian calendar. ... June 25 is the 176th day of the year (177th in leap years) in the Gregorian Calendar, with 189 days remaining. ... 2006 (MMVI) is a common year starting on Sunday of the Gregorian calendar. ... August 25 is the 237th day of the year in the Gregorian Calendar (238th in leap years), with 128 days remaining. ... 2006 (MMVI) is a common year starting on Sunday of the Gregorian calendar. ... August 13 is the 225th day of the year in the Gregorian Calendar (226th in leap years), with 140 days remaining. ...

External links

• HD 36705 -- Rotationally variable Star (in English). SIMBAD: Centre de Données astronomiques de Strasbourg. Retrieved on 2006-08-25.
• 4C05660 (in English). Astronomisches Rechen-Institut Heidelberg (1998-11-05). Retrieved on 2006-08-25.