De Casteljau's algorithm: Difference between revisions

From formulasearchengine
Jump to navigation Jump to search
← Older edit
en>XLinkBot
BOT--Reverting link addition(s) by 69.136.157.124 to revision 575712456 (https://www.youtube.com/watch?v=YATikPP2q70/ [\byoutube\.com])
en>Magioladitis
m Removing invisible Unicode character/ Replacing hard spaces See WP:CHECKWIKI error #16 fix + other fixes, replaced: → using AWB (10331)
 
(One intermediate revision by one other user not shown)
Line 1: Line 1:
{{Starbox begin
Oscar is what my spouse enjoys to contact me and I totally dig that title. What I love performing is performing ceramics but I haven't produced a dime with it. Years in the past we moved to North Dakota and I love each day living right here. He utilized to be unemployed but now he is a pc operator but his marketing by no means comes.<br><br>Also visit my web page [http://sis.inje.ac.kr/?document_srl=108234&mid=comm2 sis.inje.ac.kr]
| name=Beta Pictoris
}}
{{Starbox image
| image =
    <div style="position: relative">[[File:Pictor constellation map.svg|250px]]
    <div style="position: absolute; left: 101px; top: 95px">[[File:Locator Dot.svg|12px]]</div>
    </div> <!--http://meta.wikimedia.org/wiki/Help:Composite_images -->
| caption = The red dot shows the location of Beta Pictoris.
}}
{{Starbox observe
| epoch=J2000
| ra=05<sup>h</sup> 47<sup>m</sup> 17.1<sup>s</sup><ref name="SIMBAD"/>
| dec=&minus;51° 03&prime; 59&Prime;<ref name="SIMBAD"/>
| appmag_v=3.861<ref name="SIMBAD"/>
| constell=[[Pictor]]
}}
{{Starbox character
| class=A6V<ref name="Gray2006"/>
| b-v=0.17<ref name="Hoffleit1991"/>
| u-b=0.10<ref name="Hoffleit1991"/>
| variable=[[Delta Scuti variable]]<ref name="Koen2003"/>
}}
{{Starbox astrometry
| radial_v=+20.0 ± 0.7<ref name="Gontcharov2006"/>
| prop_mo_ra=+4.65<ref name="VanLeeuwen2007"/>
| prop_mo_dec=+83.10<ref name="VanLeeuwen2007"/>
| parallax=51.44
| p_error=0.12
| parallax_footnote=<ref name="VanLeeuwen2007"/>
| absmag_v=2.42<ref name="absmag" group="note"/>
}}
{{Starbox detail
| mass=1.75<ref name="Crifo1997"/>
| radius=1.8<ref name="Kervella2003"/>
| luminosity_bolometric=8.7<ref name="Crifo1997"/>
| temperature=8052<ref name="Gray2006"/>
| metal=112% solar<ref name="Gray2006"/><ref name="metal" group="note"/>
| rotational_velocity=130<ref name="Royer2007"/>
| gravity=4.15<ref name="Gray2006" />
| age=12{{±|8|4}} million<ref name="Zuckerman2001"/>
}}
{{Starbox catalog
| names=[[Gliese-Jahreiss catalogue|GJ]] 219, [[Harvard Revised catalogue|HR]] 2020, [[Cordoba Durchmusterung|CD]] &minus;51°1620, [[Henry Draper catalogue|HD]] 39060, [[General Catalogue of Trigonometric Parallaxes|GCTP]] 1339.00, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]] 234134, [[Hipparcos catalogue|HIP]] 27321
}}
{{Starbox end}}
'''Beta Pictoris''' (β Pic, β Pictoris) is the second brightest [[star]] in the [[constellation]] [[Pictor]].  It is located 63.4 [[light year]]s from our [[solar system]], and is 1.75 times as massive and 8.7 times as [[luminosity|luminous]] as the [[Sun]]. The Beta Pictoris system is very young, only 8–20 million years old,<ref name="Zuckerman2001"/> although it is already in the [[main sequence]] stage of its [[stellar evolution|evolution]].<ref name="Crifo1997"/> Beta Pictoris is the title member of the [[Beta Pictoris moving group]], an [[stellar association|association]] of young stars which share the same motion through space and have the same age.<ref name="Zuckerman2001"/>
 
Beta Pictoris shows an [[infrared excess|excess of infrared emission]] compared to normal stars of its type, which is caused by large quantities of dust near the star. Detailed observations reveal a large disk of dust and gas orbiting the star, which was the first [[debris disk]] to be imaged around another star.<ref name="Smith1984"/> In addition to the presence of several [[planetesimal]] belts<ref name="Wahhaj2003"/> and [[comet]]ary activity,<ref name="Beust1990"/> there are indications that [[planet]]s have formed within this disk and that the processes of planet formation may still be ongoing.<ref name="Freistetter2007"/> Material from the Beta Pictoris debris disk is thought to be the dominant source of interstellar [[meteoroid]]s in our solar system.<ref name="Baggaley2000"/>
 
The [[European Southern Observatory]] (ESO) has confirmed the presence of a planet, matching previous predictions, through the use of [[Methods of detecting extrasolar planets#Direct imaging|direct imagery]], orbiting in the plane of the debris disk surrounding the star. This planet is currently the closest extrasolar planet to its star ever photographed: the observed separation is roughly the same as the distance between [[Saturn]] and the Sun.<ref name="ESO2010"/>
 
==Location and visibility==
Beta Pictoris is a star in the southern constellation of Pictor, the [[Easel]], and is located to the west of the bright star [[Canopus]].<ref name="Kaler"/> It traditionally marked the sounding line of the ship [[Argo Navis]], before the constellation was split.<ref>{{cite journal | title = On Frederick de Houtman's Catalogue of Southern Stars, and the Origin of the Southern Constellations | author= Knobel, E. B. |journal = Monthly Notices of the Royal Astronomical Society | volume= 77| pages=414–32 [423] | bibcode = 1917MNRAS..77..414K |url=http://articles.adsabs.harvard.edu//full/1917MNRAS..77..414K/0000414.000.html |year=1917}}</ref> The distance to Beta Pictoris was found by measuring the star's [[trigonometric parallax]]. The star has an [[apparent visual magnitude]] of 3.861,<ref name="SIMBAD"/> so is visible to the [[naked eye]] under good conditions, though [[light pollution]] may result in stars dimmer than magnitude 3 being too dim to see. It is the second brightest in its constellation, exceeded only by [[Alpha Pictoris]], which has an apparent magnitude of 3.30.<ref name="Darling"/>
 
The distance to Beta Pictoris and many other stars was measured by the [[Hipparcos]] [[satellite]]. This was done by measuring its [[trigonometric parallax]]: the slight displacement in its position observed as the Earth moves around the Sun. Beta Pictoris was found to exhibit a parallax of 51.87 [[Minute of arc|milliarcsecond]]s,<ref name="Perryman1997"/> a value which was later revised to 51.44 milliarcseconds when the data was reanalyzed taking [[systematic error]]s more carefully into account.<ref name="VanLeeuwen2007"/> The distance to Beta Pictoris is therefore 63.4 light years, with an [[measurement uncertainty|uncertainty]] of 0.1 light years.<ref name="Pogge"/><ref name="parallax" group="note"/>
 
The Hipparcos satellite also measured the [[proper motion]] of Beta Pictoris: it is traveling eastwards at a rate of 4.65 milliarcseconds per year, and northwards at a rate of 83.10 milliarcseconds per year.<ref name="VanLeeuwen2007"/> Measurements of the [[Doppler shift]] of the star's spectrum reveals it is moving away from us at a rate of 20&nbsp;km/s.<ref name="Gontcharov2006"/> Several other stars share the same motion through space as Beta Pictoris and likely formed from the same gas cloud at roughly the same time: these comprise the [[Beta Pictoris moving group]].<ref name="Zuckerman2001"/>
 
==Physical properties==
 
===Spectrum, luminosity and variability===
According to measurements made as part of the Nearby Stars Project, Beta Pictoris has a [[stellar classification|spectral type]] of [[A V star|A6V]]<ref name="Gray2006"/> and has an [[effective temperature]] of {{convert|8052|K|C F|lk=on}},<ref name="Gray2006"/> which is hotter than our Sun's {{convert|5778|K|C F}}.<ref name="NASASun"/> Analysis of the spectrum reveals that the star contains a slightly higher ratio of heavy elements, which are termed [[metal (astronomy)|metal]]s in astronomy to hydrogen than our Sun. This value is expressed as the quantity [M/H], the [[base-10 logarithm]] of the ratio of the star's metal fraction to that of the Sun. In the case of Beta Pictoris, the value of [M/H] is 0.05,<ref name="Gray2006"/> which means that the star's metal fraction is 12% greater than that of our Sun.<ref name="metal" group="note"/>
 
Analysis of the spectrum can also reveal the [[surface gravity]] of the star. This is usually expressed as log <var>g</var>, the base-10 logarithm of the [[gravitational acceleration]] given in [[CGS units]], in this case, cm/s². Beta Pictoris has log&nbsp;<var>g</var>=4.15,<ref name="Gray2006"/> implying a surface gravity of 140 [[meter per second squared|m/s²]], which is about half of the gravitational acceleration at the surface of our Sun (274&nbsp;m/s²).<ref name="NASASun"/>
 
As an A-type main sequence star, Beta Pictoris is more luminous than our Sun: combining the apparent magnitude of 3.861 with the distance of 19.44 parsecs gives an [[absolute magnitude]] of 2.42, as compared to our Sun which has an absolute magnitude of 4.83.<ref name="NASASun"/><ref name="COSMOS"/><ref name="absmag" group="note"/> This corresponds to a visual luminosity 9.2 times greater than that of the Sun.<ref name="luminosity" group="note"/> When the entire spectrum of radiation from Beta Pictoris and the Sun is taken into account, Beta Pictoris is found to be 8.7 times more luminous than the Sun.<ref name="Crifo1997"/><ref name="Strobel"/>
 
Many main sequence stars of spectral type A fall into a region of the [[Hertzsprung–Russell diagram]] called the [[instability strip]], which is occupied by pulsating [[variable star]]s. In 2003, [[photometry (astronomy)|photometric]] monitoring of the star revealed variations in brightness of around 1–2 millimagnitudes on frequencies between about 30 and 40 minutes.<ref name="Koen2003"/> Radial velocity studies of Beta Pictoris also reveal variability: there are pulsations at two [[frequency|frequencies]], one at 30.4 minutes and one at 36.9 minutes.<ref name="Galland2006"/> As a result, the star is classified as a [[Delta Scuti variable]].
 
===Mass, radius and rotation===
The mass of Beta Pictoris has been determined by using models of [[stellar evolution]] and fitting them to the star's observed properties. This method yields a stellar mass between 1.7 and 1.8 [[solar mass]]es.<ref name="Crifo1997"/> The star's [[angular diameter]] has been measured using [[interferometry]] with the [[Very Large Telescope]] and was found to be 0.84 [[Minute of arc|milliarcsecond]]s.<ref name="Kervella2003"/> Combining this value with the distance of 63.4 light years gives a radius 1.8 times that of our Sun.<ref name="diameter" group="note"/>
 
The rotational velocity of Beta Pictoris has been measured to be at least 130&nbsp;km/s.<ref name="Royer2007"/> Since this value is derived by measuring [[radial velocity|radial velocities]], this is a lower limit on the true rotational velocity: the quantity measured is actually <var>v</var> [[sine|sin]](<var>i</var>), where <var>i</var> represents the inclination of the star's [[axis of rotation]] to the [[line-of-sight propagation|line-of-sight]]. If it is assumed that Beta Pictoris is viewed from Earth in its equatorial plane, a reasonable assumption since the circumstellar disk is seen edge-on, the [[rotation period]] can be calculated as approximately 16 hours, which is significantly shorter than that of our Sun (609.12 hours<ref name="NASASun"/>).<ref name="rotation" group="note"/>
 
===Age and formation===
The presence of significant amounts of dust around the star<ref name="Croswell1999"/> implies a young age of the system and led to debate about whether it had joined the main sequence or was still a [[pre–main sequence star]]<ref name="Lanz1995"/> However when the star's distance was measured by Hipparcos it was revealed that Beta Pictoris was located further away than previously thought and hence was more luminous than originally believed. Once the Hipparcos results were taken into account, it was found that Beta Pictoris was located close to the [[zero age main sequence]] and was not a pre–main sequence star after all.<ref name="Crifo1997"/> Analysis of Beta Pictoris and other stars within the Beta Pictoris moving group suggests that they are around 12 million years old.<ref name="Zuckerman2001"/> Allowing for uncertainties, the age may range between 8 and 20 million years.<ref name="Zuckerman2001"/>
 
Beta Pictoris may have been formed near the [[Scorpius-Centaurus Association]].<ref name="Ortega2004"/> The collapse of the gas cloud which resulted in the formation of Beta Pictoris may have been triggered by the [[shock wave]] from a [[supernova]] explosion: the star which went supernova may have been a former companion of [[HIP 46950]], which is now a [[runaway star]]. Tracing the path of HIP 46950 backwards suggests that it would have been in the vicinity of the [[Scorpius-Centaurus Association]] about 13 million years ago.<ref name="Ortega2004"/>
 
==Circumstellar environment==
 
===Debris disks===
[[File:HST betaPictoris comb.jpg|right|thumb|upright=1.33|Hubble Space Telescope image of the main and secondary debris disks]]
Excess [[infrared]] radiation from Beta Pictoris was detected by the [[IRAS]] spacecraft in 1983.<ref name="Croswell1999"/> Along with [[Vega]], [[Fomalhaut]] and [[Epsilon Eridani]], it was one of the first four stars from which such an excess was detected: these stars are called "Vega-like" after the first such star discovered. Since A-type stars like Beta Pictoris tend to radiate most of their energy at the blue end of the spectrum,<ref name="wavelength" group="note"/> this implied the presence of cool matter in orbit around the star, which would radiate at infrared wavelengths and produce the excess.<ref name="Croswell1999"/> This hypothesis was verified in 1984 when Beta Pictoris became the first star to have its [[circumstellar disk]] imaged optically.<ref name="Smith1984"/>
 
The debris disk around Beta Pictoris is seen edge-on by observers on Earth, and is orientated in a northeast-southwest direction. The disk is asymmetric: in the northeast direction it has been observed out to 1835 [[astronomical unit]]s from the star, while the southwest direction the extent is 1450 AU.<ref name="Larwood2001"/> The disk is rotating: the part to the northeast of the star is moving away from us, while the part to the southwest of the disc is moving towards us.<ref name="Olofsson2001"/>
 
Several elliptical rings of material have been observed in the outer regions of the debris disk between 500 and 800 AU: these may have formed as a result of the system being disrupted by a passing star.<ref name="Kalas2000"/> [[Astrometry|Astrometric]] data from the Hipparcos mission reveal that the [[red giant]] star [[Beta Columbae]] passed within 2 light years of Beta Pictoris about 110,000 years ago, but a larger perturbation would have been caused by [[Zeta Doradus]], which passed at a distance of 3 light years about 350,000 years ago.<ref name="Kalas2001"/> However computer simulations favor a lower encounter velocity than either of these two candidates, which suggest that the star responsible for the rings may have been a companion star of Beta Pictoris on an unstable orbit. The simulations suggest a perturbing star with a mass of 0.5 [[solar mass]]es is likely to blame for the structures. Such a star would be a [[red dwarf]] of spectral type M0V.<ref name="Larwood2001"/><ref name="NASA2000"/>
[[File:NASA-ExocometsAroundBetaPictoris-ArtistView.jpg|thumb|400px|left|Various [[planet formation]] processes, including [[exocomets]] and other [[planetesimals]], around ''Beta Pictoris'', a very young type [[A V star]] ([[NASA]] artist's conception).]] 
In 2006, imaging of the system with the [[Hubble Space Telescope]]'s [[Advanced Camera for Surveys]] revealed the presence of a secondary dust disk inclined at an angle of about 5° to the main disk and extending at least 130 AU from the star.<ref name="Golimowski2006"/> The secondary disk is asymmetrical: the southwest extension is more curved and less inclined than the northeast. The imaging was not good enough to distinguish between the main and secondary disks within 80 AU of Beta Pictoris, however the northeast extension of the dust disk is predicted to intersect with the main disk at about 30 AU from the star.<ref name="Golimowski2006"/> The secondary disk may be produced by a massive planet in an inclined orbit removing matter from the primary disk and causing it to move in an orbit aligned with the planet.<ref name="NASA2006b"/>
 
Studies made with the [[NASA]] [[Far Ultraviolet Spectroscopic Explorer]] have discovered that the disk around Beta Pictoris contains an extreme overabundance of [[carbon]]-rich gas.<ref name="Roberge2006"/> This helps stabilize the disk against [[radiation pressure]] which would otherwise blow the material away into interstellar space.<ref name="Roberge2006"/> Currently, there are two suggested explanations for the origin of the carbon overabundance. Beta Pictoris might be in the process of forming exotic [[carbon planet|carbon-rich planets]], in contrast to the [[terrestrial planet]]s in our solar system, which are rich in [[oxygen]] instead of carbon.<ref name="NASA2006a"/> Alternatively it may be passing through an unknown phase that might also have occurred early in the development of our solar system: in our solar system there are carbon-rich meteorites known as [[Chondrite#Enstatite chondrites|enstatite chondrite]]s, which may have formed in a carbon-rich environment. It has also been proposed that [[Jupiter]] may have formed around a carbon-rich core.<ref name="NASA2006a"/>
 
In 2011 the disk around Beta Pictoris became the first other [[planetary system]] to be photographed by an [[Amateur Astronomy|amateur astronomer]]. Rolf Olsen of [[New Zealand]] captured the disk with a 10 inch [[Newtonian reflector]] and a modified [[webcam]].<ref>Olsen, Rolf. [http://www.rolfolsenastrophotography.com/Astrophotography/Beta-Pictoris The Circumstellar Disc around Beta Pictoris], 2011-12-03.</ref>
 
===Planetesimal belts===
[[File:Ssc2005-01b.jpg|right|thumb|The dust around Beta Pictoris may be produced by the collisions of large [[planetesimals]].]]In 2003, imaging of the inner region of the Beta Pictoris system with the [[Keck II]] telescope revealed the presence of several features which are interpreted as being belts or rings of material. Belts at approximately 14, 28, 52 and 82 [[astronomical unit]]s from the star were detected, which alternate in inclination with respect to the main disk.<ref name="Wahhaj2003"/>
 
Observations in 2004 revealed the presence of an inner belt containing [[silicate]] material at a distance of 6.4 AU from the star. Silicate material was also detected at 16 and 30 AU from the star, with a lack of dust between 6.4 and 16 AU providing evidence that a massive planet may be orbiting in this region.<ref name="Okamoto2004"/><ref name="Burnham2004"/> Magnesium-rich [[olivine]] has also been detected, strikingly similar to that found in the Solar system [[comets]] and different from the olivine found in Solar system asteroids.<ref name="deVries2012">{{cite doi|10.1038/nature11469}}</ref> Olivine crystals can only form closer than 10 AU from the star; therefore they have been transported to the belt after formation, probably by [[radial mixing]]<ref name="deVries2012" />
 
Modeling of the dust disk at 100 AU from the star suggests the dust in this region may have been produced by a series of collisions initiated by the destruction of [[planetesimal]]s with radii of about 180 kilometers. After the initial collision, the debris undergoes further collisions in a process called a collisional cascade. Similar processes have been inferred in the debris disks around [[Fomalhaut]] and [[AU Microscopii]].<ref name="Quillen2007"/>
 
===Falling evaporating bodies===
The [[spectrum]] of Beta Pictoris shows strong short-term variability that was first noticed in the [[red-shift]]ed part of various absorption lines, which was interpreted as being caused by material falling onto the star.<ref name="LagrangeHenri1988"/> The source of this material was suggested to be small [[comet]]-like objects on orbits which take them close to the star where they begin to evaporate, termed the "falling evaporating bodies" model.<ref name="Beust1990"/> Transient [[blue-shift]]ed absorption events were also detected, though less frequently: these may represent a second group of objects on a different set of orbits.<ref name="Crawford1998"/> Detailed modeling indicates the falling evaporating bodies are unlikely to be mainly icy like comets, but instead are probably composed of a mixed dust and ice core with a crust of [[refractory]] material.<ref name="Karmann2001"/> These objects may have been perturbed onto their star-grazing orbits by the gravitational influence of a planet in a mildly [[eccentricity (orbit)|eccentric]] orbit around Beta Pictoris at a distance of roughly 10 AU from the star.<ref name="Thebault2001"/> Falling evaporating bodies may also be responsible for the presence of gas located high above the plane of the main debris disk.<ref name="Beust2007"/>
 
===Planetary system===
[[File:Beta Pictoris system annotated.jpg|thumb|left|[[European Southern Observatory|ESO]] image of a planet near Beta Pictoris.]]
 
{{main|Beta Pictoris b}}
 
On November 21, 2008, it was announced that infrared observations made in 2003 with the [[Very Large Telescope]] had revealed a candidate planetary companion to the star.<ref name="ESO2008"/>
In the autumn of 2009 the planet was successfully observed on the other side of the parent star, confirming the existence of the planet itself and earlier observations. It is believed that in 15 years it will be possible to record the whole orbit of the planet.<ref name="ESO2010"/>
 
{{OrbitboxPlanet short
| exoplanet = [[Beta Pictoris b|b]]
| mass = 8{{±|5|2}}
| separation = 8{{±|1.7|0.4}}
}}
 
The [[radial velocity method]] used to discover the majority of currently-known extrasolar planets is not well suited to studying A-type stars like Beta Pictoris, and its very young age makes the noise even worse. Current limits derived from this method are enough to rule out [[hot Jupiter]]-type planets more massive than 2 [[Jupiter mass]]es at a distance of less than 0.05 AU from the star. For planets orbiting at 1 AU, planets with less than 9 Jupiter masses would have evaded detection.<ref name="Freistetter2007"/><ref name="Galland2006"/> Therefore to find planets in the Beta Pictoris system, astronomers look for the effects that the planet has on the circumstellar environment.
 
Multiple lines of evidence suggested the existence of a massive planet orbiting in the region around 10 AU from the star: the dust-free gap between the planetesimal belts at 6.4 AU and 16 AU suggest this region is being cleared out;<ref name="Burnham2004"/> a planet at this distance would explain the origin of the falling evaporating bodies,<ref name="Thebault2001"/> and the warps and inclined rings in the inner disk suggest a massive planet on an inclined orbit is disrupting the disk.<ref name="NASA2006b"/><ref name="Mouillet1997"/>
[[File:Beta Pictoris.jpg|thumb|right|upright=1.25|Beta Pictoris b in both [[Elongation (astronomy)|elongations]].]]
The observed planet by itself cannot explain the structure of the planetesimal belts at 30 AU and 52 AU from the star. These belts might be associated with smaller planets at 25 and 44 AU, with around 0.5 and 0.1 Jupiter masses respectively.<ref name="Freistetter2007"/> Such a system of planets, if it exists, would be close to a 1:3:7 [[orbital resonance]]. It may also be that the rings in the outer disc at 500–800 AU are indirectly caused by the influence of these planets.<ref name="Freistetter2007"/>
 
The object was observed at an angular distance of 411 [[Minute of arc|milliarcsecond]]s from Beta Pictoris, which corresponds to a distance in the plane of the sky of 8 AU. For comparison, the orbital radii of the planets Jupiter and [[Saturn]] are 5.2 AU<ref name="NASAJupiter"/> and 9.5 AU<ref name="NASASaturn"/> respectively. The separation in the radial direction is unknown, so this is a lower limit on the true separation. Estimates of its mass depend on theoretical models of planetary evolution, and predict the object has about 8 Jupiter masses and is still cooling, with a temperature ranging from 1400–1600 K. These figures come with the caveat that the models have not yet been tested against real data in the likely ranges of mass and age for the planet.
 
The semimajor axis is 8-9 AU and its orbital period is 17–21 years.<ref name=orbit2012>{{cite journal | title=Orbital characterization of the βPictoris b giant planet | author=G. Chauvin et al. |year=2012|journal=Astronomy & Astrophysics|volume=542|arxiv=1202.2655|doi=10.1051/0004-6361/201118346|bibcode = 2012A&A...542A..41C }}</ref> A "[[transit (astronomy)|transit]]-like event" was observed in November 1981;<ref name="LecavelierDesEtangs1997"/><ref name="LeCavelierDesEtangs2009"/> this is consistent with those estimates.<ref name=orbit2012/> If this is confirmed as a true transit, the inferred radius of the transiting object is 2–4 Jupiter radii, which is larger than predicted by theoretical models. This may indicate that, as may also be the case for the planet [[Fomalhaut b]], it is surrounded by a large [[planetary rings|ring system]] or a moon-forming disc.<ref name="LeCavelierDesEtangs2009"/>
 
==Dust stream==
In 2000, observations made with the Advanced Meteor Orbit Radar facility in [[University of Canterbury|New Zealand]] revealed the presence of a stream of particles coming from the direction of Beta Pictoris, which may be a dominant source of interstellar meteoroids in our solar system.<ref name="Baggaley2000"/> The particles in the Beta Pictoris dust stream are relatively large, with radii exceeding 20 [[micrometer]]s, and their velocities suggest that they must have left the Beta Pictoris system at roughly 25&nbsp;km/s. These particles may have been ejected from the Beta Pictoris debris disk as a result of the migration of gas giant planets within the disk and may be an indication that the Beta Pictoris system is forming an [[Oort cloud]].<ref name="Krivova2003"/> Numerical modeling of dust ejection indicates radiation pressure may also be responsible and suggests that planets further than about 1 AU from the star cannot directly cause the dust stream.<ref name="Krivov2004"/>
 
==See also==
*[[51 Ophiuchi]]
 
==Notes==
{{reflist|group="note"|refs=
<ref name="absmag" group="note">The [[absolute magnitude]] <var>M<sub>V</sub></var> of the star can be calculated from its apparent magnitude <var>m<sub>V</sub></var> and distance <var>d</var> using the following equation:
 
<math>\scriptstyle M_V = m_V - 5\log_{10} \left(\frac{d}{10\mathrm{\ parsecs}}\right)</math></ref>
 
<ref name="diameter" group="note">The physical diameter can be found by multiplying the distance by the angular diameter in [[radian]]s.</ref>
 
<ref name="luminosity" group="note">The visual luminosity can be calculated by: <math>\scriptstyle\frac{L_{V_{\ast}}}{L_{V_{\odot}}} = 10^{0.4(M_{V_{\odot}} - M_{V_{\ast}})}</math></ref>
 
<ref name="metal" group="note">Calculated from [M/H]: relative abundance = 10<sup>[M/H]</sup></ref>
 
<ref name="parallax" group="note">The parallax can be converted into distance using the equation: <math>\scriptstyle\mathrm{Distance\ in\ parsecs}=\frac{1}{\mathrm{parallax\ in\ arcseconds}}</math>. See the article on [[propagation of uncertainty]] for information on how errors on derived values can be calculated.</ref>
 
<ref name="rotation" group="note">The [[rotation period]] can be calculated using the equations of [[circular motion]]:
 
<math>\scriptstyle P_{\mathrm{rot}} = \frac{2\pi r}{v_{\mathrm{rot}}}</math></ref>
 
<ref name="wavelength" group="note">From [[Wien's displacement law]] and a temperature of 8052 [[Kelvin|K]] the peak wavelength emission from Beta Pictoris would be around 360 [[nanometer]]s which is in the [[ultraviolet]] region of the spectrum.</ref>
}}
 
==References==
{{reflist|colwidth=30em|refs=
<ref name="Baggaley2000">{{cite journal|bibcode=2000JGR...10510353B|title=Advanced Meteor Orbit Radar observations of interstellar meteoroids|author=Baggaley, W. Jack|year=2000|journal=[[J. Geophys. Res.]]|volume=105|issue=A5|pages=10353–10362|doi=10.1029/1999JA900383}}</ref>
 
<ref name="Beust1990">{{cite journal|bibcode=1990A&A...236..202B|title=The Beta Pictoris circumstellar disk. X—Numerical simulations of infalling evaporating bodies|author=Beust, H.; Vidal-Madjar, A.; Ferlet, R. and Lagrange-Henri, A. M.|year=1990|journal=[[Astronomy and Astrophysics]]|volume=236|issue=1|pages=202–216}}</ref>
 
<ref name="Beust2007">{{cite journal|bibcode=2007A&A...466..201B|title=High latitude gas in the β Pictoris system. A possible origin related to falling evaporating bodies|author=Beust, H. and Valiron, P.|year=2007|journal=[[Astronomy and Astrophysics]]|volume=466|issue=1|pages=201–213|doi=10.1051/0004-6361:20053425|arxiv = astro-ph/0701241 }}</ref>
 
<ref name="Burnham2004">{{cite web|url=http://www.astronomy.com/asy/default.aspx?c=a&id=2512|title=Making planets at Beta Pictoris|year=2004|publisher=[[Astronomy Magazine]]|author=Burnham, Robert|accessdate=2008-09-02}}</ref>
 
<ref name="COSMOS">{{cite web|url=http://astronomy.swin.edu.au/cosmos/A/Absolute+Magnitude|title=Absolute Magnitude|work=COSMOS—The SAO Encyclopedia of Astronomy|accessdate=2008-09-08}}</ref>
 
<ref name="Crawford1998">{{cite journal|bibcode=1998MNRAS.294L..31C|title=Detection of a strong transient blue-shifted absorption component in the Beta Pictoris disc|author=Crawford, I. A.; Beust, H. and Lagrange, A.-M.|year=1998|journal=[[MNRAS]]|volume=294|issue=2|pages=L31–L34|doi=10.1046/j.1365-8711.1998.01373.x}}</ref>
 
<ref name="Crifo1997">{{cite journal|bibcode=1997A&A...320L..29C|title=β Pictoris revisited by Hipparcos. Star properties|author=Crifo, F. ''et al.''|year=1997|journal=[[Astronomy and Astrophysics]]|volume=320|pages=L29–L32}}</ref>
 
<ref name="Croswell1999">{{cite book|last=Croswell|first=Ken|authorlink=Ken Croswell|title=[[Planet Quest]]|year=1999|publisher=[[Oxford University Press]]|isbn=0-19-288083-7}}</ref>
 
<ref name="Darling">{{cite web|url=http://www.daviddarling.info/encyclopedia/P/Pic.html|title=Pictor (abbr. Pic, gen. Pictoris)|author=Darling, David|work=The Internet Encyclopedia of Science|accessdate=2008-09-08}}</ref>
 
<ref name="ESO2008">{{cite press release|url=http://www.eso.org/public/outreach/press-rel/pr-2008/pr-42-08.html|title=Beta Pictoris planet finally imaged?|publisher=ESO|date=2008-11-21|accessdate=2008-11-22}}</ref>
 
<ref name="ESO2010">{{cite web|title=Exoplanet Caught on the Move|url=http://www.eso.org/public/news/eso1024/|accessdate=10 June 2010|date=2010-06-10}}</ref>
 
<ref name="Freistetter2007">{{cite journal|bibcode=2007A&A...466..389F|title=Planets of β Pictoris revisited|author=Freistetter, F.; Krivov, A. V. and Löhne, T.|year=2007|journal=[[Astronomy and Astrophysics]]|volume=466|issue=1|pages=389–393|doi=10.1051/0004-6361:20066746|arxiv = astro-ph/0701526 }}</ref>
 
<ref name="Galland2006">{{cite journal|bibcode=2006A&A...447..355G|title=Extrasolar planets and brown dwarfs around A–F type stars. III. β Pictoris: looking for planets, finding pulsations|author=Galland, F. ''et al.''|year=2006|journal=[[Astronomy and Astrophysics]]|volume=447|issue=1|pages=355–359|doi=10.1051/0004-6361:20054080|arxiv = astro-ph/0510424 }}</ref>
 
<ref name="Golimowski2006">{{cite journal|bibcode=2006AJ....131.3109G|author=Golimowski, D. A. ''et al.''|title=Hubble Space Telescope ACS Multiband Coronagraphic Imaging of the Debris Disk around β Pictoris|journal=[[The Astronomical Journal]]|volume=131|issue=6|pages=3109–3130|year=2006|doi=10.1086/503801|arxiv = astro-ph/0602292 }}</ref>
 
<ref name="Gontcharov2006">{{cite web|url=http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=III/252/table8&recno=8252|title=HIP 27321|work=Pulkovo radial velocities for 35493 HIP stars|author=Gontcharov G.A.|year=2006|accessdate=2008-09-06}}</ref>
 
<ref name="Gray2006">{{cite journal|bibcode=2006AJ....132..161G|title=Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc—The Southern Sample|author=Gray, R. O. ''et al.''|year=2006|journal=[[The Astronomical Journal]]|volume=132|issue=1|pages=161–170|doi=10.1086/504637|arxiv = astro-ph/0603770 }}</ref>
 
<ref name="Hoffleit1991">{{cite web|url=http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=V/50/catalog&recno=2020|title=HR 2020|work=Bright Star Catalogue, 5th Revised Ed.|author=Hoffleit D. and Warren Jr W.H.|year=1991|accessdate=2008-09-06}}</ref>
 
<ref name="Kalas2000">{{cite journal|bibcode=2000ApJ...530L.133K|title=Rings in the Planetesimal Disk of β Pictoris|author=Kalas, P.; Larwood, J.; Smith, B. A. and Schultz, A.|year=2000|journal=[[The Astrophysical Journal]]|volume=530|issue=2|pages=L133–L137|doi=10.1086/312494|arxiv = astro-ph/0001222 }}</ref>
 
<ref name="Kalas2001">{{cite journal|bibcode=2001ApJ...553..410K|title=Stellar Encounters with the β Pictoris Planetesimal System|author=Kalas, Paul; Deltorn, Jean-Marc and Larwood, John|year=2001|journal=[[The Astrophysical Journal]]|volume=553|issue=1|pages=410–420|doi=10.1086/320632|arxiv = astro-ph/0101364 }}</ref>
 
<ref name="Kaler">{{cite web|url=http://www.astro.uiuc.edu/~kaler/sow/betapic.html|title=Beta Pictoris|author=Kaler, Jim|work=STARS|accessdate=2008-09-08}}</ref>
 
<ref name="Karmann2001">{{cite journal|bibcode=2001A&A...372..616K|title=The physico-chemical history of Falling Evaporating Bodies around beta Pictoris: investigating the presence of volatiles|author=Karmann, C.; Beust, H. and Klinger, J.|year=2001|journal=[[Astronomy and Astrophysics]]|volume=372|issue=2|pages=616–626|doi=10.1051/0004-6361:20010528}}</ref>
 
<ref name="Kervella2003">{{cite conference|url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2003IAUS..219E.127K&db_key=AST&nosetcookie=1|title=VINCI/VLTI Observations of Main Sequence Stars|author=Kervella, P.|year=2003|editor=A.K. Dupree and A.O. Benz|publisher=Astronomical Society of the Pacific|conference=IAUS 219: Stars as Suns: Activity, Evolution and Planets|booktitle=Proceedings of the 219th symposium of the International Astronomical Union|location=Sydney, Australia|pages=80|accessdate=2008-09-07}}</ref>
 
<ref name="Koen2003">{{cite journal|bibcode=2003MNRAS.341.1385K|title=δ Scuti pulsations in β Pictoris|author=Koen, C.|year=2003|journal=[[MNRAS]]|volume=341|issue=4|pages=1385–1387|doi=10.1046/j.1365-8711.2003.06509.x}}</ref>
 
<ref name="Krivov2004">{{cite journal|bibcode=2004A&A...417..341K|title=Towards understanding the β Pictoris dust stream|author=Krivov, A. V. ''et al.''|year=2004|journal=[[Astronomy and Astrophysics]]|volume=417|issue=1|pages=341–352|doi=10.1051/0004-6361:20034379}}</ref>
 
<ref name="Krivova2003">{{cite journal|bibcode=2003A&A...402L...5K|title=A stream of particles from the β Pictoris disc: A possible ejection mechanism|author=Krivova, N. A. and Solanki, S. K.|year=2003|journal=[[Astronomy and Astrophysics]]|volume=402|issue=1|pages=L5–L8|doi=10.1051/0004-6361:20030369}}</ref>
 
<ref name="LagrangeHenri1988">{{cite journal|bibcode=1988A&A...190..275L|title=The Beta Pictoris circumstellar disk. VI - Evidence for material falling on to the star|author=Lagrange-Henri, A. M.; Vidal-Madjar, A. and Ferlet, R.|journal=[[Astronomy and Astrophysics]]|volume=190|pages=275–282|year=1988}}</ref>
 
<ref name="Lanz1995">{{cite journal|bibcode=1995ApJ...447L..41L|title=HST/GHRS Observations of the beta Pictoris System: Basic Parameters of the Age of the System|author=Lanz, Thierry; Heap, Sara R. and Hubeny, Ivan|year=1995|journal=The Astrophysical Journal Letters|volume=447|issue=1|pages=L41|doi=10.1086/309561}}</ref>
 
<ref name="Larwood2001">{{cite journal|bibcode=2001MNRAS.323..402L|title=Close stellar encounters with planetesimal discs: the dynamics of asymmetry in the β Pictoris system|author=Larwood, J. D. and Kalas, P. G.|journal=[[MNRAS]]|volume=323|issue=2|pages=402–416|year=2001|doi=10.1046/j.1365-8711.2001.04212.x|arxiv = astro-ph/0011279 }}</ref>
 
<ref name="LecavelierDesEtangs1997">{{cite journal|bibcode=1997A&A...328..311L|title=Beta Pictoris light variations. I. The planetary hypothesis|author=Lecavelier des Etangs, A. ''et al.''|journal=[[Astronomy and Astrophysics]]|volume=328|pages=311–320|year=1997}}</ref>
 
<ref name="LeCavelierDesEtangs2009">{{cite arXiv|eprint=0903.1101|class=astro-ph|title=Is Beta Pic b the transiting planet of November 1981?|last1=Lecavelier des Etangs | first1=A.|last2=Vidal-Madjar | first2=A.|year=2009|doi=10.1051/0004-6361/200811528}}</ref>
 
<ref name="Mouillet1997">{{cite journal|bibcode=1997MNRAS.292..896M|title=A planet on an inclined orbit as an explanation of the warp in the Beta Pictoris disc|author=Mouillet, D.; Larwood, J. D.; Papaloizou, J. C. B. and Lagrange, A. M.|year=1997|journal=[[MNRAS]]|volume=292|pages=896–904|arxiv = astro-ph/9705100 }}</ref>
 
<ref name="NASA2000">{{cite press release|url=http://hubblesite.org/newscenter/archive/releases/2000/02/text/|title=Beta Pictoris Disk Hides Giant Elliptical Ring System|publisher=NASA|date=2000-01-15|accessdate=2008-09-02}}</ref>
 
<ref name="NASA2006a">{{cite press release|url=http://www.nasa.gov/vision/universe/starsgalaxies/betapic.html|title=NASA's Fuse Finds Infant Solar System Awash in Carbon|date=2006-06-07|publisher=NASA|accessdate=2006-07-03}}</ref>
 
<ref name="NASA2006b">{{cite press release|url=http://hubblesite.org/newscenter/archive/releases/2006/25/full/|title=Hubble Reveals Two Dust Disks Around Nearby Star Beta Pictoris|publisher=NASA|date=2006-06-27|accessdate=2008-09-02}}</ref>
 
<ref name="NASAJupiter">{{cite web|url=http://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html|title=Jupiter Fact Sheet|publisher=NASA|accessdate=2009-07-10}}</ref>
 
<ref name="NASASaturn">{{cite web|url=http://nssdc.gsfc.nasa.gov/planetary/factsheet/saturnfact.html|title=Saturn Fact Sheet|publisher=NASA|accessdate=2009-07-10}}</ref>
 
<ref name="NASASun">{{cite web|url=http://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html|title=Sun Fact Sheet|publisher=NASA|accessdate=2008-09-07}}</ref>
 
<ref name="Okamoto2004">{{cite journal|url=http://www.nature.com/nature/journal/v431/n7009/abs/nature02948.html|title=An early extrasolar planetary system revealed by planetesimal belts in β Pictoris|author=Okamoto, Yoshiko Kataza ''et al.''|journal=[[Nature (journal)|Nature]]|year=2004|volume=431|issue=7009|pages=660–663|doi=10.1038/nature02948|pmid=15470420|bibcode = 2004Natur.431..660O }}</ref>
 
<ref name="Olofsson2001">{{cite journal|bibcode=2001ApJ...563L..77O|title=Widespread Atomic Gas Emission Reveals the Rotation of the β Pictoris Disk|author=Olofsson, G.; Liseau, R. and Brandeker, A.|year=2001|journal=[[The Astrophysical Journal]]|volume=563|issue=1|pages=L77–L80|doi=10.1086/338354|arxiv = astro-ph/0111206 }}</ref>
 
<ref name="Ortega2004">{{cite journal|bibcode=2004ApJ...609..243O|title=New Aspects of the Formation of the β Pictoris Moving Group|author=Ortega, V. G. ''et al.''|year=2004|journal=[[The Astrophysical Journal]]|volume=609|issue=1|pages=243–246|doi=10.1086/420958}}</ref>
 
<ref name="Pogge">{{cite web|url=http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit1/distances.html|author=Pogge, Richard|title=Lecture 5: Distances of the Stars|work=Astronomy 162: Introduction to Stars, Galaxies, & the Universe|accessdate=2008-09-08}}</ref>
 
<ref name="Perryman1997">{{cite web|url=http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I/239/hip_main&recno=27301|title=HIP 27321|work=The Hipparcos and Tycho Catalogues|author=ESA|year=1997|accessdate=2008-09-07}}</ref>
 
<ref name="Quillen2007">{{cite journal|bibcode=2007MNRAS.380.1642Q|title=Planetary embryos and planetesimals residing in thin debris discs|author=Quillen, Alice C.; Morbidelli, Alessandro and Moore, Alex|journal=[[MNRAS]]|year=2007|volume=380|issue=4|pages=1642–1648|doi=10.1111/j.1365-2966.2007.12217.x}}</ref>
 
<ref name="Roberge2006">{{cite journal|bibcode=2006Natur.441..724R|title=Stabilization of the disk around β Pictoris by extremely carbon-rich gas|author=Roberge, Aki ''et al.''|year=2006|journal=[[Nature (journal)|Nature]]|volume=441|issue=7094|pages=724–726|doi=10.1038/nature04832|pmid=16760971|arxiv = astro-ph/0604412 }}</ref>
 
<ref name="Royer2007">{{cite web|url=http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=J/A%2bA/463/671/table4&recno=381|title=HD 39060|work=Rotational velocities of A-type stars. III. List of the 1541 B9- to F2-type stars, with their vsini value, spectral type, associated subgroup and classification|author=Royer F.; Zorec J. and Gomez A.E.|year=2007|accessdate=2008-09-07}}</ref>
 
<ref name="SIMBAD">{{cite web|url=http://simbad.u-strasbg.fr/simbad/sim-id?protocol=html&Ident=bet+pic|title=* bet Pic—Star|work=SIMBAD|accessdate=2008-09-06}}</ref>
 
<ref name="Smith1984">{{cite journal|bibcode=1984Sci...226.1421S|title=A circumstellar disk around Beta Pictoris|author=Smith, B. A. and Terrile, R. J.|year=1984|journal=[[Science (journal)|Science]]|volume=226|pages=1421–1424|doi=10.1126/science.226.4681.1421|pmid=17788996|issue=4681}}</ref>
 
<ref name="Strobel">{{cite web|url=http://www.astronomynotes.com/starprop/s4.htm|author=Strobel, Nick|work=Astronomy Notes|title=Magnitude System|accessdate=2008-09-08}}</ref>
 
<ref name="Thebault2001">{{cite journal|bibcode=2001A&A...376..621T|title=Falling evaporating bodies in the β Pictoris system. Resonance refilling and long term duration of the phenomenon|author=Thébault, P. and Beust, H.|year=2001|journal=[[Astronomy and Astrophysics]]|volume=376|issue=2|pages=621–640|doi=10.1051/0004-6361:20010983}}</ref>
 
<ref name="VanLeeuwen2007">{{cite web|url=http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I/311/hip2&recno=27251|title=HIP 27321|work=Hipparcos, the New Reduction|author=van Leeuwen, F.|year=2007|accessdate=2008-09-06}}</ref>
 
<ref name="Wahhaj2003">{{cite journal|bibcode=2003ApJ...584L..27W|title=The Inner Rings of β Pictoris|author=Wahhaj, Z. ''et al.''|journal=[[The Astrophysical Journal]]|volume=584|issue=1|pages=L27–L31|year=2003|doi=10.1086/346123|arxiv = astro-ph/0212081 }}</ref>
 
<ref name="Zuckerman2001">{{cite journal|bibcode=2001ApJ...562L..87Z|title=The β Pictoris Moving Group|author=Zuckerman, B. ''et al.''|year=2001|journal=[[The Astrophysical Journal]]|volume=562|issue=1|pages=L87–L90|doi=10.1086/337968}}</ref>
 
}}
 
==External links==
* [http://www.disksite.com/ The Circumstellar Disk Learning Site]
* [http://www.astro.uiuc.edu/~kaler/sow/betapic.html Beta Pictoris]
* [http://www2.ess.ucla.edu/~jewitt/beta.html Dr. David Jewitt's page on Beta Pic]
* [http://www.solstation.com/stars2/beta-pic.htm Beta Pictoris] at SolStation.
* [http://www.ari.uni-heidelberg.de/aricns/cnspages/4c00467.htm ARICNS]
* [http://www.seds.org/~spider/spider/Misc/betaPic.html SEDS entry]
* [http://exoplanet.eu/star.php?st=beta+Pic Notes for star Beta Pictoris]
{{Nearest star systems|13}}
{{Stars of Pictor}}
 
{{good article}}
 
[[Category:Bayer objects|Pictoris, Beta]]
[[Category:Pictor (constellation)]]
[[Category:Circumstellar disks|Pictoris, Beta]]
[[Category:A-type main-sequence stars]]
[[Category:Hypothetical planetary systems]]
[[Category:Exoplanets detected by direct imaging]]
[[Category:Beta Pictoris moving group]]
[[Category:Objects within 100 ly of Earth]]
{{Link GA|zh}}

Latest revision as of 19:22, 26 July 2014

Oscar is what my spouse enjoys to contact me and I totally dig that title. What I love performing is performing ceramics but I haven't produced a dime with it. Years in the past we moved to North Dakota and I love each day living right here. He utilized to be unemployed but now he is a pc operator but his marketing by no means comes.

Also visit my web page sis.inje.ac.kr

Retrieved from "https://en.formulasearchengine.com/index.php?title=De_Casteljau%27s_algorithm&oldid=233130"