V404 Cygni: Difference between revisions
Clarified what was unusual about the 2015 outburst per Kimura et al. (2016). |
it's a microquasar, reffix and new information regarding pair plasma |
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'''V404 Cygni''' is a [[binary star|binary]] system consisting of a [[black hole]] with a mass of about {{val|12|3|u=[[solar mass]]es}}<ref>{{cite journal|title=The mass of the black hole in V404 Cygni|author=Shahbaz, T.|journal=MNRAS|year=1994|volume=271|pages=L1–L14|bibcode=1994MNRAS.271L..10S|last2=Ringwald|first2=F. A.|last3=Bunn|first3=J. C.|display-authors=4|last4=Naylor|first4=T.|last5=Charles|first5=P. A.|last6=Casares|first6=J.}}</ref> and a [[Stellar classification|late G or early K]] companion star of mass slightly smaller than the [[Sun]] in the constellation of [[Cygnus (constellation)|Cygnus]]. The star and the black hole [[orbit]] each other every {{val|6.47129|u=days}} at fairly close range. Due to their proximity the [[main sequence star]] would be distorted into egg shape by the black hole's gravity and lose mass to the black hole.<ref name="Kimura-Nature">{{cite journal |last1=Kimura |first1=Mariko |displayauthors=etal |title=Repetitive patterns in rapid optical variations in the nearby black-hole binary V404 Cygni |journal=Nature |date=7 January 2016 |volume=529 |pages=54-70 |doi=10.1038/nature16452}}</ref> |
'''V404 Cygni''' is a [[microquasar]] and a [[binary star|binary]] system consisting of a [[black hole]] with a mass of about {{val|12|3|u=[[solar mass]]es}}<ref>{{cite journal|title=The mass of the black hole in V404 Cygni|author=Shahbaz, T.|journal=MNRAS|year=1994|volume=271|pages=L1–L14|bibcode=1994MNRAS.271L..10S|last2=Ringwald|first2=F. A.|last3=Bunn|first3=J. C.|display-authors=4|last4=Naylor|first4=T.|last5=Charles|first5=P. A.|last6=Casares|first6=J.}}</ref> and a [[Stellar classification|late G or early K]] companion star of mass slightly smaller than the [[Sun]] in the constellation of [[Cygnus (constellation)|Cygnus]]. The star and the black hole [[orbit]] each other every {{val|6.47129|u=days}} at fairly close range. Due to their proximity the [[main sequence star]] would be distorted into egg shape by the black hole's gravity and lose mass to the black hole.<ref name="Kimura-Nature">{{cite journal |last1=Kimura |first1=Mariko |displayauthors=etal |title=Repetitive patterns in rapid optical variations in the nearby black-hole binary V404 Cygni |journal=Nature |date=7 January 2016 |volume=529 |pages=54-70 |doi=10.1038/nature16452}}</ref> |
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The "V" in the name indicates that it is a [[variable star]], which repeatedly gets brighter and fainter over time. It is also considered a [[nova]], because at least three times in the 20th century it produced a bright outburst of energy. Finally, it is a [[soft X-ray transient]] because it periodically emits short bursts of X-rays. |
The "V" in the name indicates that it is a [[variable star]], which repeatedly gets brighter and fainter over time. It is also considered a [[nova]], because at least three times in the 20th century it produced a bright outburst of energy. Finally, it is a [[soft X-ray transient]] because it periodically emits short bursts of X-rays. |
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==Discovery== |
==Discovery== |
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On May 22, 1989 the Japanese [[Ginga (satellite)|Ginga]] Team discovered a new X-ray source that was cataloged as [[GS 2023+338]]. This source was subsequently identified as coincident in position with a previously known nova cataloged as V404 Cygni. |
On May 22, 1989 the Japanese [[Ginga (satellite)|Ginga]] Team discovered a new X-ray source that was cataloged as [[GS 2023+338]]. This source was subsequently identified as coincident in position with a previously known nova cataloged as V404 Cygni.<ref> {{cite journal |title=The 1989 outburst of V404 cygni: A very unusual x-ray nova |author=R. M. Wagner, S. Starrfield, A. Cassatella, R. Gonzalez-Riestra, T. J. Kreidl, S. B. Howell, R. M. Hjellming, X. -H. Han, G. Sonneborn |journal=[[Lecture Notes in Physics]] |volume=369 |pages=429-430 |date=24 July 2005 |doi=10.1007/3-540-53500-4_162 }}</ref> |
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==2015 Outburst== |
==2015 Outburst== |
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On 15 June 2015 [[NASA]]'s [[Swift Gamma-Ray Burst Mission|Swift]] and [[Fermi Gamma-ray Space Telescope|Fermi]] satellites detected the first signs of renewed activity. A worldwide observing campaign was commenced and on 17 June [[European Space Agency|ESA]]'s [[INTEGRAL]] [[Gamma-ray]] observatory started monitoring the outburst. INTEGRAL has been detecting "repeated bright flashes of light time scales shorter than an hour, something rarely seen in other black hole systems", and during these flashes V404 Cygni is the brightest object in the [[X-ray]] sky - up to fifty times brighter than the [[Crab Nebula]]. This outburst is the first since 1989. Other outbursts occurred in 1938 and 1956, and the outbursts are probably caused by material piling up in a disk around the black hole until a tipping point is reached.<ref name="integral">{{cite web|title=Monster Black Hole Wakes Up After 26 Years|url=http://www.esa.int/Our_Activities/Space_Science/Integral/Monster_black_hole_wakes_up_after_26_years|website=integral|publisher=ESA|accessdate=26 June 2015|archiveurl=http://www.webcitation.org/6ZZdUla2A|archivedate=26 June 2015}}</ref> The outburst was unusual in that physical processes in the inner accretion disk were detectable in optical [[Photometry (astronomy)|photometry]] from small telescopes; previously, these variations were thought to be detectable with space-based X-ray telescopes only.<ref name="Kimura-Nature" /> |
On 15 June 2015 [[NASA]]'s [[Swift Gamma-Ray Burst Mission|Swift]] and [[Fermi Gamma-ray Space Telescope|Fermi]] satellites detected the first signs of renewed activity. A worldwide observing campaign was commenced and on 17 June [[European Space Agency|ESA]]'s [[INTEGRAL]] [[Gamma-ray]] observatory started monitoring the outburst. INTEGRAL has been detecting "repeated bright flashes of light time scales shorter than an hour, something rarely seen in other black hole systems", and during these flashes V404 Cygni is the brightest object in the [[X-ray]] sky - up to fifty times brighter than the [[Crab Nebula]]. This outburst is the first since 1989. Other outbursts occurred in 1938 and 1956, and the outbursts are probably caused by material piling up in a disk around the black hole until a tipping point is reached.<ref name="integral">{{cite web|title=Monster Black Hole Wakes Up After 26 Years|url=http://www.esa.int/Our_Activities/Space_Science/Integral/Monster_black_hole_wakes_up_after_26_years|website=integral|publisher=ESA|accessdate=26 June 2015|archiveurl=http://www.webcitation.org/6ZZdUla2A|archivedate=26 June 2015}}</ref> The outburst was unusual in that physical processes in the inner accretion disk were detectable in optical [[Photometry (astronomy)|photometry]] from small telescopes; previously, these variations were thought to be detectable with space-based X-ray telescopes only.<ref name="Kimura-Nature" /> An detailed analysis of the INTEGRAL data revealed the existence of a [[pair plasma]] near the black hole. This plasma consists of [[electron]]s and their [[antimatter]] counterparts, [[positron]]s.<ref> {{cite web |title=Gamma rays reveal pair plasma from a flaring black hole binary system |publisher=[[Max Planck Institute for Astrophysics]] |url=http://www.mpe.mpg.de/6517171/News_20160229 |date=29 February 2016 }}</ref> |
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==References== |
==References== |
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{{reflist}} |
{{reflist}} |
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*"V404 Cyg: 10 years in quiescence" Elena P. Pavlenko, Yuliana G. Kuznetsova, Sergei Yu. Shugarov and Vladislav S. Petrov. Astrophysics and Space Science Supplement, '''276''', pp. 65–66 |
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*"The 1989 outburst of V404 cygni: A very unusual x-ray nova" R. M. Wagner, S. Starrfield, A. Cassatella, R. Gonzalez-Riestra, T. J. Kreidl, S. B. Howell, R. M. Hjellming, X. -H. Han, G. Sonneborn |
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{{Stars of Cygnus}} |
{{Stars of Cygnus}} |
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Revision as of 14:09, 1 March 2016
V404 Cygni is a microquasar and a binary system consisting of a black hole with a mass of about 12±3 solar masses[1] and a late G or early K companion star of mass slightly smaller than the Sun in the constellation of Cygnus. The star and the black hole orbit each other every 6.47129 d at fairly close range. Due to their proximity the main sequence star would be distorted into egg shape by the black hole's gravity and lose mass to the black hole.[2] The "V" in the name indicates that it is a variable star, which repeatedly gets brighter and fainter over time. It is also considered a nova, because at least three times in the 20th century it produced a bright outburst of energy. Finally, it is a soft X-ray transient because it periodically emits short bursts of X-rays.
In 2009, the black hole in the V404 Cygni system became the first black hole to have an accurate parallax measurement for its distance from the Solar System. Measured by very-long-baseline interferometry using the High Sensitivity Array, the distance is 2.39±0.14 kiloparsecs,[3] or (7.80±0.46)×103 light-years.
Discovery
On May 22, 1989 the Japanese Ginga Team discovered a new X-ray source that was cataloged as GS 2023+338. This source was subsequently identified as coincident in position with a previously known nova cataloged as V404 Cygni.[4]
2015 Outburst
On 15 June 2015 NASA's Swift and Fermi satellites detected the first signs of renewed activity. A worldwide observing campaign was commenced and on 17 June ESA's INTEGRAL Gamma-ray observatory started monitoring the outburst. INTEGRAL has been detecting "repeated bright flashes of light time scales shorter than an hour, something rarely seen in other black hole systems", and during these flashes V404 Cygni is the brightest object in the X-ray sky - up to fifty times brighter than the Crab Nebula. This outburst is the first since 1989. Other outbursts occurred in 1938 and 1956, and the outbursts are probably caused by material piling up in a disk around the black hole until a tipping point is reached.[5] The outburst was unusual in that physical processes in the inner accretion disk were detectable in optical photometry from small telescopes; previously, these variations were thought to be detectable with space-based X-ray telescopes only.[2] An detailed analysis of the INTEGRAL data revealed the existence of a pair plasma near the black hole. This plasma consists of electrons and their antimatter counterparts, positrons.[6]
References
- ^ Shahbaz, T.; Ringwald, F. A.; Bunn, J. C.; Naylor, T.; et al. (1994). "The mass of the black hole in V404 Cygni". MNRAS. 271: L1–L14. Bibcode:1994MNRAS.271L..10S.
- ^ a b Kimura, Mariko (7 January 2016). "Repetitive patterns in rapid optical variations in the nearby black-hole binary V404 Cygni". Nature. 529: 54–70. doi:10.1038/nature16452.
{{cite journal}}: Unknown parameter|displayauthors=ignored (|display-authors=suggested) (help) - ^ Miller-Jones, J. A. C.; Jonker; Dhawan (2009). "The first accurate parallax distance to a black hole". The Astrophysical Journal Letters. 706 (2): L230. arXiv:0910.5253. Bibcode:2009ApJ...706L.230M. doi:10.1088/0004-637X/706/2/L230.
- ^ R. M. Wagner, S. Starrfield, A. Cassatella, R. Gonzalez-Riestra, T. J. Kreidl, S. B. Howell, R. M. Hjellming, X. -H. Han, G. Sonneborn (24 July 2005). "The 1989 outburst of V404 cygni: A very unusual x-ray nova". Lecture Notes in Physics. 369: 429–430. doi:10.1007/3-540-53500-4_162.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ "Monster Black Hole Wakes Up After 26 Years". integral. ESA. Archived from the original on 26 June 2015. Retrieved 26 June 2015.
- ^ "Gamma rays reveal pair plasma from a flaring black hole binary system". Max Planck Institute for Astrophysics. 29 February 2016.