Wys bron van S2 (ster)

U het geen regte om om hierdie bladsy te wysig nie, vir die volgende rede:
Your IP address is in a range that has been blocked on all Wikimedia Foundation wikis.
The block was made by ‪Jon Kolbert‬. The reason given is Open proxy/Webhost: See the help page if you are affected .
Start of block: 05:35, 21 Februarie 2024
Expiry of block: 05:35, 21 Februarie 2029
Your current IP address is 3.81.84.12. The blocked range is 3.81.0.0/16.
Sluit asseblief al bogenoemde besonderhede in by enige navrae wat jy maak. If you believe you were blocked by mistake, you can find additional information and instructions in the No open proxies global policy.
Otherwise, to discuss the block please post a request for review on Meta-Wiki. You could also send an email to the stewards VRT queue at stewards@wikimedia.org including all above details.
U het toestemming om die bronteks te bekyk en te kopieer.
{{Inligtingskas ster
| naam= S2
| beeld= Eso1622b.jpg
| onderskrif= 'n Beeld van die galaktiese middelpunt, met die posisie van S2 aangedui. <br>'''Erkenning''': ESO / Max Planck-instituut vir Buiteaardse Fisika / Gillessen et al.
| sterrebeeld= [[Boogskutter (sterrebeeld)|Boogskutter]]
| bayernaam= 
| spektraaltipe= B0-2 V<ref name=paumard>{{cite journal |doi=10.1086/503273 |bibcode=2006ApJ...643.1011P |arxiv=astro-ph/0601268 |title=The two young star disks in the central parsec of the galaxy: Properties, dynamics, and formation |journal=The Astrophysical Journal |volume=643 |issue=2 |pages=1011–1035 |year=2006 |last1=Paumard |first1=T. |last2=Genzel |first2=R. |last3=Martins |first3=F. |last4=Nayakshin |first4=S. |last5=Beloborodov |first5=A.M. |last6=Levin |first6=Y. |last7=Trippe |first7=S. |last8=Eisenhauer |first8=F. |last9=Ott |first9=T. |last10=Gillessen |first10=S. |last11=Abuter |first11=R. |last12=Cuadra |first12=J. |last13=Alexander |first13=T. |last14=Sternberg |first14=A.|s2cid=14440768 }}</ref>
| soort= 
| RK= {{RK|17|45|40.0442}}<ref name=schodel>{{cite journal |doi=10.1051/0004-6361/200810922 |bibcode=2009A&A...502...91S |arxiv=0902.3892 |title=The nuclear star cluster of the Milky Way: Proper motions and mass |journal=Astronomy & Astrophysics |volume=502 |issue=1 |pages=91–111 |year=2009 |last1=Schödel |first1=R. |last2=Merritt |first2=D. |last3=Eckart |first3=A.|s2cid=219559 }}</ref>
| Dek= {{Dek|−29|00|27.975}}<ref name=schodel/>
| afstand= Byna 26 000<ref name="geom"/>
| rotasiespoed= 
| veranderlik= 
| veelvoudig= 
| name= [CRG2004] 13, [GKM98] S0–2, [PGM2006] E1, [EG97] S2, [GPE2000] 0.15, [SOG2003] 1, S0–2.
}}

'''S2''', ook bekend as '''S0-2''', is 'n [[ster]] in die [[sterreswerm]] naby [[Sagittarius A*]], die [[supermassiewe swartkolk]] in die middel van die [[Melkweg]]. Dit wentel in 'n tydperk van 16,0518&nbsp;jaar om die swartkolk, met 'n [[halwe lengteas]] van sowat 970&nbsp;[[AE]] en 'n [[Apside|perisentrum]] (naaste afstand) van 17&nbsp;[[Ligjaar|ligure]] of 120&nbsp;AE. Sy wentelperiode is net 30% langer as dié van [[Jupiter]] om die [[Son]], maar dit kom nie nader as omtrent vier keer die afstand van [[Neptunus]] van die Son af nie. Die [[massa]] van die ster toe dit gevorm het, word deur die [[Europese Suidelike Sterrewag]] (ESO) geraam op sowat {{val|14|ul=mson}} (sonmassas).<ref>{{cite journal |last1=Habibi |first1=M. |display-authors=etal |year=2017 |title=Twelve years of spectroscopic Monitoring in the galactic center: The closest look at S-stars near the black hole |journal=The Astrophysical Journal |volume=847 |issue=2 |page=120 |doi=10.3847/1538-4357/aa876f |bibcode=2017ApJ...847..120H |arxiv=1708.06353|s2cid=119078556 }}</ref> 

Die veranderende skynbare posisie van die ster word sedert 1995 deur twee groepe gemonitor (by die UCLA en die Max Planck-instituut vir Buiteaardse Fisika) as deel van 'n poging om bewyse te kry vir die bestaan van 'n supermassiewe swartkolk in die middel van die Melkweg. Die bewyse dui al hoe meer aan dat Sgr&nbsp;A* deel van so 'n swartkolk is. Teen 2008 is S2 vir 'n hele omwenteling waargeneem.<ref>{{YouTube|KCADH3x56eE|A short documentary on Sagittarius A*}}</ref>

'n Span sterrekundiges, hoofsaaklik van die Max Planck-instituut, het waarnemings van S2 se wenteldinamika om Sgr&nbsp;A* gebruik om die [[Aarde]] se afstand van die galaktiese middelpunt af te meet. Hulle het bepaal dié afstand is byna {{nowrap|26 000 ± 2 000 [[ligjare]]}} ({{nowrap|7,94 ± 0,42 [[Parsek|kiloparsek]]}}), wat baie nou ooreenstem met vorige berekenings.<ref name="geom">
{{cite journal
  |last1=Eisenhauer
  |first1=F.
  |display-authors=etal
  |year=2003
  |title=A Geometric Determination of the Distance to the Galactic Center
  |journal=The Astrophysical Journal
  |volume=597 |issue=2 |pages=L121–L124
  |doi=10.1086/380188
  |bibcode=2003ApJ...597L.121E
  |arxiv=astro-ph/0306220
 }}</ref><ref>{{cite web |url=http://www2011.mpe.mpg.de/ir/GC/papers/nature2002.pdf |publisher=Max-Planck-Institut für extraterrestrische Physik |department=Infrared/Submillimeter Astronomy |title=Galactic Center Research |access-date=2013-03-26 |archive-date=2006-09-06 |archive-url=https://web.archive.org/web/20060906131419/http://www2011.mpe.mpg.de/ir/GC/papers/nature2002.pdf |url-status=dead }}</ref> Dié afstand is belangrik in die kalibrering van astronomiese afstandskale.

S2 is presies gemonitor tydens sy nabye afstand in Mei&nbsp;2018 van Sgr&nbsp;A* af, en die resultate stem ooreen met voorspellings volgens [[algemene relatiwiteit]].<ref name=TuanDo>{{cite journal
 |title=Relativistic redshift of the star S0–2 orbiting the Galactic center supermassive black hole
 |first1=Tuan |last1=Do |display-authors=etal
 |journal=Science |volume=365 |issue=6454 |date=16 Augustus 2019
 |doi=10.1126/science.aav8137 |arxiv=1907.10731 |pages=664–668
|pmid=31346138 |bibcode=2019Sci...365..664D }}</ref>

==Naam==
Die naam S0-2 is in 1998 die eerste keer gebruik. "S0" dui 'n ster aan binne 'n [[boogsekonde]] van [[Sagittarius A*|Sgr&nbsp;A*]], die middelpunt van die [[Melkweg]], en S0-2 was die tweede naaste ster toe die afstande gemeet is.<ref name=gkm>{{cite journal |doi=10.1086/306528 |bibcode=1998ApJ...509..678G |arxiv=astro-ph/9807210 |title=High Proper‐Motion Stars in the Vicinity of Sagittarius&nbsp;A*: Evidence for a supermassive black hole at the center of our galaxy |journal=The Astrophysical Journal |volume=509 |issue=2 |pages=678–686 |year=1998 |last1=Ghez |first1=A.M. |last2=Klein |first2=B.L. |last3=Morris |first3=M. |last4=Becklin |first4=E.E.|s2cid=18243528 }}</ref>

Vroeër is die ster bloot as S2 aangeteken, omdat dit die tweede van 11 [[infrarooi]]bronne naby die galaktiese middelpunt is (die sterre is by benadering antikloksgewys genommer).<ref name=eg>{{cite journal |doi=10.1093/mnras/284.3.576 |bibcode=1997MNRAS.284..576E |title=Stellar proper motions in the central 0.1&nbsp;pc of the Galaxy |journal=Monthly Notices of the Royal Astronomical Society |volume=284 |issue=3 |pages=576–598 |year=1997 |last1=Eckart |first1=A. |last2=Genzel |first2=R.}}</ref> Dit is toevallig dat die ster op albei lyste die nommer "2" het; ander katalogusse nommer dit anders.<ref name=gkm/>

==Wentelbaan==
Die hoogs [[Eksentrisiteit (sterrekunde)|eksentrieke]] wentelbaan van S2 sal sterrekundiges die geleentheid gee om vir verskillende uitwerkings wat deur algemene relatiwiteit voorspel word en selfs vir buitedimensionele effekte te toets.<ref>{{cite news |url=https://www.sciencenews.org/blog/on-the-scene/black-hole-peephole |title=Black hole as peep-hole |website=ScienceNews}}</ref> Dié effekte het 'n maksimum bereik met S2 se naaste afstand in die middel van 2018.<ref>{{cite AV media |people=Ghez, Andrea M.|date=19 April 2016 |title=Black Holes @ 100 Workshop: Galactic Center |publisher=Black Hole Initiative |medium=video lecture |url=https://www.youtube.com/watch?v=7z5jBJXbuuo#t=31:55  |archive-url=https://ghostarchive.org/varchive/youtube/20211220/7z5jBJXbuuo |archive-date=2021-12-20 |url-status=live|time=31:55 |time-caption=Remarks beginning at |location=Harvard University</ref><ref name="badAstr">{{cite web |url=http://www.syfy.com/syfywire/a-star-is-about-to-plunge-head-first-toward-a-monster-black-hole-astronomers-are-ready-to |title=A star is about to plunge head first toward a monster black hole. Astronomers are ready to watch |date=2018-03-07 |df=dmy-all}}</ref> As in ag geneem word die onlangse raming van 4,31&nbsp;miljoen sonmassas vir die massa van Sgr&nbsp;A* en S2 se naaste afstand, maak dit S2 se wentelbaan die vinnigste ballistiese wentelbaan, wat snelhede van vinniger as 5&nbsp;000&nbsp;km/s (of {{breuk|1|60}} van die [[ligsnelheid]]) bereik, en in snelheid toeneem met sowat 1,5&nbsp;m/s<sup>2</sup> (amper 'n sesde van die Aarde se oppervlaksnelheid).<ref>{{cite press release |url=http://www.eso.org/public/news/eso0226/ |title=Surfing a black hole |publisher=ESO}}</ref>

Die beweging van S2 is ook nuttig om die teenwoordigheid van ander voorwerpe naby Sgr&nbsp;A* te bespeur. Daar is vermoedelik duisende sterre, sowel as donker steroorblyfsels ([[Swartkolk|sterswartkolke]], [[neutronster]]re en [[witdwerg]]e) wat versprei is in die volume waardeur S2 beweeg. Dié voorwerpe sal S2 se wentelbaan versteur en veroorsaak dat dit geleidelik afwyk van die [[Keplerwentelbaan]], wat beweging om 'n enkele [[Puntdeeltjie|puntmassa]] kenmerk.<ref>{{cite journal
 |first1=Nadeen |last1=Sabha 
 |first2=Andreas |last2=Eckart 
 |first3=David |last3=Merritt 
 |first4=Mohammad |last4=Zamaninasab 
 |first5=Gunther |last5=Witzel 
 |first6=Macarena |last6=García-Marín 
 |first7=Behrang |last7=Jalali 
 |first8=Monica |last8=Valencia-S. 
 |first9=Senol |last9=Yazici 
 |first10=Rainer |last10=Buchholz 
 |first11=Banafsheh |last11=Shahzamanian 
 |first12=Christian |last12=Straubmeier 
 |display-authors=8
 |date=September 2012
 |title=The S-Star Cluster at the Center of the Milky Way: On the nature of diffuse NIR emission in the inner tenth of a parsec 
 |journal=Astronomy and Astrophysics
 |volume=545 |page=A70
 |doi=10.1051/0004-6361/201219203 |arxiv=1203.2625 |bibcode=2012A&A...545A..70S|s2cid=118358113 
 }}</ref> Tot dusver is die enigste beperking wat op dié oorblyfsels geplaas kan word, dat hulle totale massa minder beslaan as 1% van die massa van die supermassiewe swartkolk.<ref>{{cite journal |last1=Gillessen |first1=S. |display-authors=etal |year=2009 |title=Monitoring stellar orbits around the massive black hole in the galactic center |journal=The Astrophysical Journal |volume=692 |issue=2 |pages=1075–1109 |doi=10.1088/0004-637X/692/2/1075 |arxiv=0810.4674 |bibcode=2009ApJ...692.1075G|s2cid=1431308 }}</ref>

===Naaste afstand in 2018===
In 2018 het S2 die naaste aan Sgr&nbsp;A* gekom: 120&nbsp;[[AE]], of sowat 1&nbsp;400 keer sy [[Schwarzschild-radius]], met 'n snelheid van 7&nbsp;650&nbsp;km/s of amper 3% van die ligsnelheid.<ref name=":0">{{Cite journal|last=Witze|first=Alexandra|date=2018-07-26|title=Milky Way's black hole provides long-sought test of Einstein's general relativity|journal=Nature|language=en|volume=560|issue=7716|pages=17|doi=10.1038/d41586-018-05825-3|pmid=30065325|bibcode=2018Natur.560...17W}}</ref><ref name="2017-07-26_TG">{{cite news|last=Devlin|first=Hannah|date=26 Jul 2018|title=Star spotted speeding near black hole at centre of Milky Way|newspaper=The Guardian|url=https://www.theguardian.com/science/2018/jul/26/star-spotted-speeding-near-milky-way-black-hole-for-first-time|access-date=2021-01-18}}</ref> S2 het sy naaste afstand op 19 Mei 2018 bereik. Sy vinnigste snelheid van die Aarde af gesien was in April, en sy stadigste snelheid laat in Augustus en vroeg in September.<ref name=":0" />

Onafhanklike ontleding deur die GRAVITY-samewerking<ref name="aa33718-18">{{cite journal
 |url=https://www.aanda.org/articles/aa/full_html/2018/07/aa33718-18/aa33718-18.html
 |title=Detection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black hole
 |first1=Reinhard |last1=Genzel 
 |display-authors=etal
 |collaboration=GRAVITY collaboration
 |journal=Astronomy & Astrophysics
 |doi=10.1051/0004-6361/201833718 |doi-access=free
 |type=Letter to the editor
 |date=2018-07-26 |df=dmy-all
 |volume=615 |page=L15
 |arxiv=1807.09409 |bibcode=2018A&A...615L..15G
}}</ref><ref>{{Cite web|title=First Successful Test of Einstein's General Relativity Near Supermassive Black Hole - Culmination of 26 years of ESO observations of the heart of the Milky Way|url=https://www.eso.org/public/news/eso1825/|access-date=2021-01-17|website=www.eso.org|language=en}}</ref> (onder Reinhard Genzel) en die KECK/UCLA-galaktiesesentrumgroep<ref>{{Cite journal|last1=Do|first1=Tuan|last2=Hees|first2=Aurelien|last3=Ghez|first3=Andrea|last4=Martinez|first4=Gregory D.|last5=Chu|first5=Devin S.|last6=Jia|first6=Siyao|last7=Sakai|first7=Shoko|last8=Lu|first8=Jessica R.|last9=Gautam|first9=Abhimat K.|last10=O’Neil|first10=Kelly Kosmo|last11=Becklin|first11=Eric E.|date=2019-08-16|title=Relativistic redshift of the star S0-2 orbiting the Galactic center supermassive black hole|url=https://www.science.org/doi/10.1126/science.aav8137|journal=Science|volume=365|issue=6454|pages=664–668|language=en|doi=10.1126/science.aav8137|issn=0036-8075|pmid=31346138|arxiv=1907.10731|bibcode=2019Sci...365..664D|s2cid=198901506}}</ref><ref>{{Cite web|last=Siegel|first=Ethan|date=2019-08-01|title=General Relativity Rules: Einstein Victorious In Unprecedented Gravitational Redshift Test|url=https://medium.com/starts-with-a-bang/general-relativity-rules-einstein-victorious-in-unprecedented-gravitational-redshift-test-7ab4076bcd61|access-date=2021-01-17|website=Medium|language=en}}</ref> (onder Andrea Ghez) het 'n gesamentlike omgekeerde [[Doppler-effek]] en gravitasionele [[rooiverskuiwing]] van tot 200&nbsp;km/s/c onthul, in ooreenkoms met voorspellings volgens algemene relatiwiteit. Bykomende ontledings het 'n Schwarzschild-presessie van 12 boogminute (0,2 grade) onthul in S2 se wentelbaan wat deur die nabye afstand veroorsaak is, wat ten volle ooreenstem met algemene relatiwiteit.<ref>{{Cite journal|last1=Abuter|first1=R.|last2=Amorim|first2=A.|last3=Bauböck|first3=M.|last4=Berger|first4=J. P.|last5=Bonnet|first5=H.|last6=Brandner|first6=W.|last7=Cardoso|first7=V.|last8=Clénet|first8=Y.|last9=Zeeuw|first9=P. T. de|last10=Dexter|first10=J.|last11=Eckart|first11=A.|date=2020-04-01|title=Detection of the Schwarzschild precession in the orbit of the star S2 near the Galactic centre massive black hole|url=https://www.aanda.org/articles/aa/abs/2020/04/aa37813-20/aa37813-20.html|journal=Astronomy & Astrophysics|language=en|volume=636|pages=L5|doi=10.1051/0004-6361/202037813|arxiv=2004.07187|bibcode=2020A&A...636L...5G|issn=0004-6361|doi-access=free}}</ref><ref>{{Cite web|last=|first=|date=April 16, 2020|title=Dance around the heart of our Milky Way|url=https://www.mpg.de/14692117/detection-of-schwarzschild-precession-in-the-orbit-of-star-s2|access-date=2021-01-18|website=Max Planck Society|language=en}}</ref><ref>{{Cite news|last=Sai Zhai|date=Aug 4, 2020|title=The first detection of the Schwarzschild precession in the orbit of the star S2|url=https://astrobites.org/2020/08/04/the-first-detection-of-the-schwarzschild-precession-in-the-orbit-of-the-star-s2/|access-date=2021-01-18|newspaper=Astrobites|language=en-US}}</ref>

==Verwysings==
{{Verwysings|3}}

==Skakels==
{{vertaaluit| taalafk = en | il = S2 (star)}}

{{Normdata}}

[[Kategorie:Melkweg]]
[[Kategorie:Swartkolke]]
[[Kategorie:Sterre]]
[[Kategorie:Boogskutter (sterrebeeld)]]
Sjablone wat op hierdie bladsy gebruik word:
Keer terug na S2 (ster).
Ontsluit van "https://af.wikipedia.org/wiki/S2_(ster)"