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Word die vier sterre genoem in die titelsterre wat supernova gaan word, of is dit sterre wat in die middel van die lewe is, soos ons Son, maar net soveel groter is as ons Son?
NML Cygni en VY Canis Majoris
Zhang et al. (2012) het verskeie waardes vir $ T _ { text {eff}} $ (effektiewe temperatuur) en $ L $ (helderheid) en bevind dat NML Cygni ooreenstem met die evolusiespoor van 'n ster van massa $ sim25M_ odot $, naby die HR-diagram van 'n soortgelyke ster, VY Canis Majoris (aangedui as VY CMa). Met behulp van hierdie datapunte word in die model beraam dat NML Cygni ongeveer 8 miljoen jaar oud is en in die fase na sy hoofreeks van sy lewe.
Daar word egter vermoed dat NML Cygni verband hou met die Cygnus OB2-vereniging, wat 'n ouderdom van 2-3 miljoen jaar het. Dit is vreemd omdat al die sterre in die assosiasie byna dieselfde ouderdom moet wees (sien Knodlseder (2008)). Die ouderdom kan egter bevraagteken word, aangesien bewyse vir ouer sterre in die omgewing aangebied is (sien Wright et al. (2010)).
Die presiese ligging van VY Canis Majoris op die evolusionêre spore is nie seker nie. Massey et al. (2006) het modelle geskep wat dit op 'n laer massa-baan geplaas het om die "verbode sone" buite die Hayashi-limiet te vermy.
VV Cephei
Op grond van standaardparameters, sterwindmetings en Geneefse roosters, het Bennett (2010) voorgestel dat die rooi superreusekomponent van VV Cephei naby die einde van sy lewe kan wees, met die veronderstelling dat 'n massa van $ sim20 $-$ 25M_ odot $.
UY Scuti
Wikipedia beweer
UY Scuti moet litium, koolstof, suurstof, neon en silikon binne die volgende miljoen jaar versmelt. Hierna sal die kern yster begin produseer, wat die balans van swaartekrag en straling in sy kern sal onderbreek en tot 'n kernval-supernova lei.
Sover ek weet word die bewering slegs gemaak deur growwe beramings van evolusionêre spore, nie deur presiese berekeninge nie. Ons weet wel dat UY Scuti beslis in die latere periode van sy waterstofverbrandingsfase is, as dit inderdaad op daardie stadium in sy lewe is. Arroyo-Torres et al. (2013) glo waarnemings plaas dit naby evolusiespore van sterre wat met massas $ sim25 $-$ 40 miljoen _ { odot} $. Daarom het dit dalk al 'n aansienlike fraksie van sy oorspronklike massa verloor - nie verbasend vir 'n rooi hipergigant nie.
Wat is 'n ster?
A Ster in sy eenvoudigste vorm is reuse hemelliggame van gas wat deur kernreaksie lig, hitte en energie opwek. Hulle kan duisende en miljoen keer so groot soos die aarde wees. Die naaste ster aan ons is die Son, dan die binêre sterre van Alpha en Proxima Centauri. Hulle wissel in kleur van rooi, die koelste (3500c) tot die warmste, wat blou is (45000c). Die sterre word volgens hul temperatuur geklassifiseer en in die onderstaande tabel word die verskillende klasse, kleur, temperatuur en 'n monsterster gelys. Hulle klas is geen aanduiding van die grootte nie, want Betelgeuse en Rigel is vergelykend in grootte. Die verskil is dat Betelgeuse oud is, terwyl Rigel relatief nuut is. Al die sterre wat op hierdie webwerf uiteengesit word, is in die Melkweg; daar is skaars data daar vir sterre in die ander sterrestelsels of die res van die heelal. Elke ster het sy eie sonnestelsel en in ons sonnestelsel is daar net een ster, dit is die son.
Sterre word as superreuse geklassifiseer op grond van hul spektrale helderheidsklas. Hierdie stelsel gebruik sekere diagnosespektrale lyne om die oppervlakteswaartekrag van 'n ster te skat en bepaal dus die grootte daarvan in verhouding tot sy massa. Groter sterre is helderder by 'n gegewe temperatuur en kan nou in bande met verskillende helderheid gegroepeer word. [2]
Die helderheidsverskille tussen sterre is die duidelikste by lae temperature, waar reuse-sterre baie helderder is as hoofreekssterre. Superreuse het die laagste swaartekrag op die oppervlak en is dus die grootste en helderste by 'n bepaalde temperatuur.
Die Yerkes of Morgan-Keenan (MK) klassifikasiestelsel [3] is byna universeel. Dit groepeer sterre in vyf hoofliggroepe wat volgens Romeinse syfers aangedui word:
Spesifiek vir superreuse, word die helderheidsklas verder verdeel in normale superreuse van klas Ib en helderste reuse van klas Ia. Die intermediêre klas Iab word ook gebruik. Uitsonderlike helder lae lae swaartekrag, sterre met sterk aanduidings van massaverlies, kan deur helderheidsklas 0 (nul) aangedui word, hoewel dit selde gesien word. [4] Vaker word die benaming Ia-0 gebruik, [5] en meer algemeen nog Ia +. [6] Hierdie hipergigante spektrale klassifikasies word baie selde toegepas op rooi reuse, hoewel die term rooi hipergiant soms gebruik word vir die mees uitgebreide en onstabiele rooi reuse soos VY Canis Majoris en NML Cygni. [7] [8]
Die "rooi" deel van "rooi superreus" verwys na die koel temperatuur. Rooi superreuse is die coolste superreuse, M-tipe, en ten minste sommige K-tipe sterre, hoewel daar geen presiese afsnyding is nie. K-tipe superreuse is ongewoon in vergelyking met M-tipe, omdat dit 'n kortstondige oorgangstadium is en ietwat onstabiel is. Die K-tipe sterre, veral vroeë of warmer K-soorte, word soms beskryf as oranje superreuse (bv. Zeta Cephei), of selfs as geel (bv. Geel hyperreus HR 5171 Aa). [9]
| Spektraal tipe | Temperatuur (K) |
|---|---|
| K1-1.5 | 4,100 |
| K2-3 | 4,015 |
| K5-M0 | 3,840 |
| M0 | 3,790 |
| M1 | 3,745 |
| M1.5 | 3,710 |
| M2 | 3,660 |
| M2.5 | 3,615 |
| M3 | 3,605 |
| M3.5 | 3,550 |
| M4-4.5 | 3,535 |
| M5 | 3,450 |
Rooi superreuse is koel en groot. Hulle het spektrale soorte K en M, dus oppervlaktemperature onder 4 100 K. [9] Hulle is tipies 'n paar honderd tot meer as duisend keer die radius van die son, [9] hoewel grootte nie die primêre faktor is in 'n ster wat aangewys word nie. as 'n superreus. 'N Helder koel reusester kan maklik groter wees as 'n warmer superreus. Alpha Herculis word byvoorbeeld geklassifiseer as 'n reuse-ster met 'n radius van tussen 264 en 303 R ☉ terwyl Epsilon Pegasi 'n K2-superreus van slegs 185 R is ☉.
Alhoewel rooi superreuse baie koeler is as die son, is dit soveel groter as baie helder, gewoonlik tien of honderdduisende liter. ☉. [9] Daar is 'n boonste grens van die straal van 'n rooi superreus teen ongeveer 1,500 R ☉. [9] Sterre bo hierdie radius sou te onstabiel wees en eenvoudig nie vorm nie.
Rooi superreuse het massas tussen ongeveer 10 M ☉ en 40 M ☉. Hoofreekssterre is massiewer as ongeveer 40 M ☉ moenie uitbrei en verkoel om rooi superreuse te word nie Rooi reuse aan die bopunt van die moontlike massa- en helderheidsgebied is die bekendste. Hul lae swaartekrag op die oppervlak en hoë helderheid veroorsaak uiterste massaverlies, miljoene keer hoër as die son, wat waarneembare newels rondom die ster oplewer. [10] Teen die einde van hul lewe het rooi superreuse moontlik 'n aansienlike fraksie van hul aanvanklike massa verloor. Die meer massiewe superreuse verloor baie vinniger massa en dit lyk asof alle rooi superreuse 'n soortgelyke massa in die orde van 10 M bereik ☉ teen die tyd dat hul kerne ineenstort. Die presiese waarde hang af van die aanvanklike chemiese samestelling van die ster en die rotasiesnelheid daarvan. [11]
Die meeste rooi superreuse toon 'n sekere mate van visuele wisselvalligheid, maar slegs selde met 'n goed gedefinieerde periode of amplitude. Daarom word hulle gewoonlik as onreëlmatige of semiregulêre veranderlikes geklassifiseer. Hulle het selfs hul eie subklasse, SRC en LC vir onderskeidelik stadige semi-reëlmatige en stadig onreëlmatige superreuse veranderlikes. Variasies is gewoonlik stadig en met klein amplitude, maar amplitudes tot vier groottes is bekend. [12]
Statistiese ontleding van baie bekende veranderlike rooi superreuse toon 'n aantal waarskynlike oorsake vir variasie: slegs 'n paar sterre toon groot amplitudes en sterk geraas, wat dui op wisselvalligheid op baie frekwensies, wat gedink word om sterk sterwind aan te dui wat teen die einde van die lewe van 'n rooi plaasvind. superreus meer algemeen is gelyktydige radiale modusvariasies oor 'n paar honderd dae en waarskynlik nie-radiale modusvariasies oor 'n paar duisend dae, maar slegs 'n paar sterre lyk regtig onreëlmatig, met klein amplitudes, waarskynlik as gevolg van fotosferiese korreling. Rooi superreus-fotosfere bevat 'n relatiewe klein aantal baie groot konveksieselle in vergelyking met sterre soos die son. Dit veroorsaak variasies in die helderheid van die oppervlak wat kan lei tot sigbare helderheidsvariasies as die ster draai. [13]
Die spektra van rooi superreuse is soortgelyk aan ander koel sterre, wat oorheers word deur 'n woud van absorpsielyne van metale en molekulêre bande. Sommige van hierdie eienskappe word gebruik om die helderheidsklas te bepaal, byvoorbeeld sekere naby-infrarooi sianogeensterkte en die Ca II-drieling. [14]
Maser-emissie kom algemeen voor uit die sirkelvormige materiaal rondom rooi superreuse. Dit kom meestal voor uit H2O en SiO, maar hidroksiel (OH) emissie vind ook plaas in smal streke. [15] Benewens die hoë resolusie-kartering van die sirkelvormige materiaal rondom rooi superreuse, kan [16] VLBI- of VLBA-waarnemings van masers gebruik word om akkurate parallakses en afstande tot hul bronne af te lei. [17] Tans word dit hoofsaaklik op individuele voorwerpe toegepas, maar dit kan nuttig word vir die ontleding van die galaktiese struktuur en die ontdekking van andersins verduisterde rooi superreussterre. [18]
Oppervlakte-oorvloed van rooi superreuse word oorheers deur waterstof, alhoewel waterstof in die kern heeltemal verbruik is. In die laaste stadiums van massaverlies, voordat 'n ster ontplof, kan oppervlakhelium verryk word tot vlakke wat vergelykbaar is met waterstof. In teoretiese modelle vir uiterste massaverlies kan voldoende waterstof verlore gaan sodat helium die mees algemene element op die oppervlak word. Wanneer voorrooi superreuse-sterre die hoofreeks verlaat, is suurstof meer volop as koolstof aan die oppervlak, en stikstof is minder volop as een van die twee, wat weerspieël in die oorvloed van die stervorming. Koolstof en suurstof word vinnig uitgeput en stikstof word verbeter as gevolg van die uitdun van CNO-verwerkte materiaal uit die samesmeltingslae. [19]
Daar word waargeneem dat rooi superreuse stadig of baie stadig draai. Modelle dui aan dat selfs vinnig draaiende hoofreekssterre gerem moet word deur hul massaverlies, sodat rooi reuse amper glad nie kan draai nie. Daardie rooi superreuse soos Betelgeuse wat wel 'n matige rotasietempo het, het dit moontlik verkry nadat hulle die rooi superreusstadium bereik het, miskien deur middel van binêre interaksie. Die kern van rooi superreuse draai steeds en die differensiële rotasiesnelheid kan baie groot wees. [20]
Superreus-helderheidsklasse is maklik om te bepaal en is van toepassing op groot getalle sterre, maar hulle groepeer 'n aantal heel verskillende soorte sterre in 'n enkele kategorie. 'N Evolusionêre definisie beperk die term superreus tot massiewe sterre wat kern heliumfusie begin sonder om 'n ontaarde heliumkern te ontwikkel en sonder om 'n heliumflits te ondergaan. Hulle sal oor die algemeen swaarder elemente verbrand en kern-ineenstorting ondergaan, wat 'n supernova tot gevolg het. [21]
Minder massiewe sterre kan 'n superreuse spektrale helderheidsklas ontwikkel teen relatief lae helderheid, ongeveer 1 000 L ☉, wanneer hulle op die asimptotiese reuse-tak (AGB) is wat heliumskulp verbrand. Navorsers verkies dit nou om te kategoriseer as AGB-sterre wat verskil van superreuse, omdat dit minder massief is, aan die oppervlak verskillende chemiese samestellings het, verskillende soorte polsasie en wisselvalligheid ondergaan en op 'n ander manier sal ontwikkel en gewoonlik 'n planetêre newel en 'n wit dwerg sal produseer. . [22] Die meeste AGB-sterre sal nie supernovas word nie, hoewel daar belangstelling in 'n klas super-AGB-sterre, dié wat amper massief genoeg is om volle koolstofversmelting te ondergaan, wat eienaardige supernovas kan produseer, alhoewel sonder om ooit 'n ysterkern te ontwikkel. [23] Een opmerklike groep sterre met 'n lae massa met 'n hoë helderheid is die RV Tauri-veranderlikes, AGB- of post-AGB-sterre wat op die onstabiliteitsstrook lê en kenmerkende semi-reëlmatige variasies toon.
Rooi reuse ontwikkel uit hoofreekssterre met massas tussen ongeveer 8 M ☉ en 30 M ☉. Sterre met 'n hoër massa koel nooit genoeg af om rooi superreuse te word nie. Sterre met 'n laer massa ontwikkel 'n ontaarde heliumkern tydens 'n rooi reuse-fase, ondergaan 'n heliumflits voordat hulle helium op die horisontale tak smelt, ontwikkel langs die AGB terwyl hulle helium in 'n dop rondom 'n ontaarde koolstof-suurstofkern verbrand en verloor dan vinnig hul buitenste lae om 'n wit dwerg met 'n planetêre newel te word. [11] AGB-sterre kan spektra ontwikkel met 'n superreusagtige helderheidsklas namate hulle uitbrei tot ekstreme afmetings in verhouding tot hul klein massa, en hulle kan die helderheid tienduisend keer die son bereik. Intermediêre "super-AGB" -sterre, ongeveer 9 M ☉, kan koolstofversmelting ondergaan en kan 'n elektronopvang-supernova produseer deur die ineenstorting van 'n suurstofneonkern. [23]
Hoofreekssterre, wat waterstof in hul kerne verbrand, met massas tussen 10 en 30 M ☉ temperatuur tussen ongeveer 25.000K en 32.000K en spektrale soorte vroeë B, moontlik baie laat O. Dit is alreeds baie helder sterre van 10.000-100.000 L ☉ as gevolg van vinnige versmelting van waterstof met die CNO-siklus en hulle het volledig konvektiewe kern. In teenstelling met die son, is die buitenste lae van hierdie warm hoofreekssterre nie konvektief nie. [11]
Hierdie voorrooi superreusagtige hoofreekssterre put die waterstof in hul kern uit na 5-20 miljoen jaar. Hulle begin dan 'n dop waterstof rondom die nou hoofsaaklik heliumkern verbrand, en dit laat hulle uitbrei en afkoel tot superreuse. Hul helderheid neem toe met 'n faktor van ongeveer drie. Die oppervlak van helium is nou tot 40%, maar daar is min verryking van swaarder elemente. [11]
Die superreuse hou aan om af te koel en die meeste sal vinnig deur die Cepheid-onstabiliteitsstrook beweeg, alhoewel die mees massiewe 'n kort tydjie as geel hyperreuse sal deurbring. Hulle sal laat K- of M-klas bereik en 'n rooi superreus word. Helium-samesmelting in die kern begin glad, óf terwyl die ster uitbrei, óf as dit al 'n rooi superreus is, maar dit veroorsaak min onmiddellike verandering aan die oppervlak. Rooi superreuse ontwikkel diep konveksie sones wat vanaf die oppervlak tot halfpad tot by die kern strek en dit veroorsaak sterk verryking van stikstof aan die oppervlak, met 'n mate van verryking van swaarder elemente. [25]
Sommige rooi superreuse ondergaan blou lusse waar hulle tydelik in temperatuur toeneem voordat hulle na die rooi superreusetoestand terugkeer. Dit hang af van die massa, rotasietempo en chemiese samestelling van die ster. Terwyl baie rooi superreuse nie 'n blou lus sal ervaar nie, kan sommige dit hê. Temperature kan 10 000 K bereik op die hoogtepunt van die blou lus. Die presiese redes vir blou lusse wissel in verskillende sterre, maar dit hou altyd verband met die toename van die heliumkern as 'n deel van die massa van die ster en dwing hoër massaverlies van die buitenste lae af. [20]
Alle rooi superreuse sal die helium binne een of twee miljoen jaar in hul kerne uitput en dan koolstof begin verbrand. Dit gaan voort met die samesmelting van swaarder elemente totdat 'n ysterkern opbou, wat dan onvermydelik in duie stort om 'n supernova te produseer. Die tyd vanaf die aanvang van koolstofversmelting totdat die kern ineenstort, is nie meer as 'n paar duisend jaar nie. In die meeste gevalle vind kern-ineenstorting plaas terwyl die ster nog 'n rooi superreus is, die groot oorblywende waterstofryke atmosfeer uitgestoot word, en dit word 'n tipe II-supernovaspektrum opgelewer. Die ondeursigtigheid van hierdie uitgestote waterstof neem af namate dit afkoel en dit veroorsaak 'n lang vertraging van die daling in helderheid na die aanvanklike supernovapiek, die kenmerk van 'n tipe II-P supernova. [11] [25]
Daar word verwag dat die helderste rooi superreuse, byna sonkragmetaal, die meeste van hul buitenste lae sal verloor voordat hul kernkern ineenstort, en daarom ontwikkel hulle weer na geel hiperreuse en helderblou veranderlikes. Sulke sterre kan ontplof as tipe II-L supernovas, steeds met waterstof in hul spektra, maar nie met voldoende waterstof om 'n verlengde helderheidsplato in hul ligkrommes te veroorsaak nie. Sterre met nog minder waterstof oorblywende kan die ongewone tipe IIb-supernova produseer, waar daar so min waterstof oorbly dat die waterstoflyne in die aanvanklike tipe II-spektrum vervaag na die voorkoms van 'n Type Ib-supernova. [26]
Die waargenome stamvaders van tipe II-P supernovas het almal temperature tussen 3 500 K en 4 400 K en helderheid tussen 10 000 L ☉ en 300 000 L ☉. Dit stem ooreen met die verwagte parameters van rooi reuse met 'n laer massa. Daar is 'n klein aantal stamvaders van tipe II-L en tipe IIb supernovas waargeneem, wat almal 'n helderheid van ongeveer 100 000 L het. ☉ en ietwat hoër temperature tot 6000 K. Dit is 'n goeie pasmaat vir rooi reuse met 'n hoër massa met 'n hoë massaverlieskoers. Daar is geen supernova-stamvaders bekend wat ooreenstem met die helderste rooi superreuse nie, en daar word verwag dat dit na Wolf Rayet-sterre sal ontwikkel voordat dit ontplof. [20]
Rooi superreuse is noodwendig nie meer as ongeveer 25 miljoen jaar oud nie, en daar word verwag dat sulke massiewe sterre slegs in relatief groot sterretrosse sal vorm, dus sal hulle na verwagting meestal naby prominente trosse voorkom. Hulle is egter redelik kortstondig in vergelyking met ander fases in die lewe van 'n ster en vorm slegs van relatief ongewone massiewe sterre, dus sal daar gewoonlik net 'n klein aantal rooi superreuse in elke groep wees. Die massiewe Hodge 301-groep in die Tarantula-newel bevat drie. [27] Tot die 21ste eeu was die grootste aantal rooi superreuse wat in 'n enkele groep bekend was, vyf in NGC 7419. [28] Die meeste rooi superreuse word afsonderlik aangetref, byvoorbeeld Betelgeuse in die Orion OB1 Vereniging en Antares in die Scorpius-Centaurus Vereniging .
Sedert 2006 is 'n reeks massiewe trosse geïdentifiseer naby die basis van die Crux-Scutum Arm van die sterrestelsel, wat elk veelvuldige rooi superreuse bevat. RSGC1 bevat ten minste 12 rooi superreuse, RSGC2 (ook bekend as Stephenson 2) bevat ten minste 26 (Stephenson 2-18, een van die sterre, is moontlik die grootste ster wat bekend is), RSGC3 bevat minstens 8 en RSGC4 (ook bekend aangesien Alicante 8) ook minstens 8. bevat. Altesaam 80 bevestigde rooi reuse is binne 'n klein area in die lug in die rigting van hierdie trosse geïdentifiseer. Dit lyk asof hierdie vier trosse 10-20 miljoen jaar gelede deel is van 'n massiewe uitbarsting van stervorming aan die einde van die balk in die middel van die sterrestelsel. [29] Soortgelyke massiewe trosse is naby die einde van die galaktiese staaf gevind, maar nie so 'n groot aantal rooi superreuse nie. [30]
Rooi superreuse is seldsame sterre, maar hulle is op 'n groot afstand sigbaar en is dikwels wisselvallig, en daar is 'n aantal bekende voorbeelde met blote oog:
Ander voorbeelde het bekend geword vanweë hul enorme grootte, meer as 1 000 R ☉:
In 'n opname sou na verwagting feitlik alle Magellanic Cloud-rooi superreuse [31] vasgevang word, het ongeveer 'n dosyn M-sterre M opgespoorv−7 en helderder, ongeveer 'n kwartmiljoen keer helderder as die son, en vanaf ongeveer 1000 keer die sonstraal opwaarts.
Is die sterre NML Cygni, UY Scuti, VY Canis Majoris en VV Cephei naby die einde van hul lewe? - Sterrekunde
Niks in die heelal bly onveranderd nie, en sterre is geen uitsondering nie. Maar ons kan nie waarneem dat 'n ster verander nie, want dit leef vir miljarde en miljarde jare. Die oorsprong van alle sterre is gas- en stofwolke wat stadig verspreide atome in die ruimte vorm. Die sterre kom in groepe voor, waarvan die meeste verdeel is, maar ander word deur swaartekrag bymekaar gehou. Die leeftyd van 'n ster hang af van die massa daarvan. Hoe meer massa, hoe vinniger waterstofbrandstof gebruik, en hoe korter word hul stormagtige lewensduur. Sommige is eenvoudig so groot dat hulle ontplof. Maar die meeste, net soos ons son, het 'n stabiele leeftyd en skyn sterk.
Ontmoet die Top 20 van die grootste sterre hiervan, wat ons heelal is.
1. WOH G64
Skrywer Europese Suidelike Sterrewag
WOH G64 is 'n rooi sterre in die Groot Magellaanse Wolk. Met 'n 2000 keer die sonstraal is dit die grootste bekende ster.
Die grootte van WOH G64 word geskat op 2,985 miljard kilometer. Sy is een van die grootste sterre wat bekend is.
2. VV Cephei
VV Cephei is 'n binêre stelsel wat in die Cepheus-konstellasie geleë is.
Die stelsel bestaan uit die sterre VV Cephei A (rooi reus) en 'n maat genaamd VV Cephei blue B. Die stelsel is ongeveer 8359 jaar lig van die sonnestelsel geleë. Dit is 6327 miljoen (uitgespreek ses honderd twee en dertig miljoen sewe honderdduisend) keer groter as die aarde. VV Cephei A het 'n volume van ongeveer 6.000.000.000 (ses biljoen) sonne.
3. NML Cygni of V1489 Cygni
NML Cygni of V1489 Cygni is 'n rooi hipergigant-ster. Dit is een van die grootste sterre wat bekend is, met ongeveer 1650 sonstrale of 7,67 AU. Dit is een van die helderste superreuse. Die afstand vanaf die aarde word geskat op 1,6 kpc of ongeveer 5 300 ligjare.
4. V354 Cephei
V354 Cephei is 'n rooi sterre wat in die Melkweg bestaan. Is ongeveer 9000 ligjare weg van die son en word tans beskou as die vierde grootste bekende ster, met 'n deursnee van 2 116 600 000 km, 1520 keer groter as die son. As dit in die middel van die sonnestelsel geplaas word, sal die oppervlak tussen die baan van Jupiter en Saturnus uitstrek.
5. KW Sagitarii
KW Sagitarii is 'n hipergigant-rooi ster. Dit is ongeveer 9800 jaar lig van die son af. Dit is een van die grootste bekende sterre.
Dit is ongeveer 9800 jaar lig van die son af. Dit is een van die grootste sterre wat bekend is, met 'n deursnee van 1460 keer groter as die son en 'n volume van 3 miljard Sonne. Die lig van hierdie ster skyn 370 000 keer meer as ons son. Dit is geleë in die konstellasie Boogskutter.
6. VY Canis Majoris
Humphrey Model: VY Canis Majoris (VY CMa) is 'n rooi sterre in die sterrebeeld Canis Major. Dit is een van die grootste bekende sterre, met 'n radius van ongeveer 1420 sonstrale. 'N Span sterrekundiges onder leiding van Roberta Humphreys, Universiteit van Minnesota, het oorspronklik 'n sonstraalstraal van 1800-2100 geskat, wat dit die grootste bekende radius sou maak. 'N Meer onlangse studie uit direkte waarnemings beraam egter 'n radius van 1420 ± 120 sonstraal.
Massey-Levesque-Plez-model: 'N Span sterrekundiges onder leiding van Roberta Humphreys, Universiteit van Minnesota, het oorspronklik 'n radius van 1800-2100 sonstraal na VY Canis Majoris beraam, wat dit die grootste bekende ster Radius sou maak. 'N Meer onlangse studie uit direkte waarnemings het 'n radius van 1420 ± 120 sonstraal geskat.
7. KY Cygni
KY Cygni is 'n rooi oormatige ster (spektrale klas M3M) in die sterrebeeld Cygnus. Dit is een van die grootste sterre wat bekend is, met 'n deursnee van ongeveer 1420 keer groter as die son en sy skyn 300 000 keer meer as die son. Dit is ongeveer 5200 ligjaar vanaf die son.
8. Mu Cephei (μ Cep, μ Cephei)
Mu Cephei (μ Cep, μ Cephei), ook bekend as Herschel & # 8217s Garnet Star is 'n rooi superreuse-ster in die konstellasie Cepheus. Dit is een van die grootste en helderste sterre wat in die Melkweg bekend is. Het 'n spektrale klassifikasie van M2 Ia.
Sedert 1943 dien die spektrum van hierdie ster as die basis waarvolgens ander sterre geklassifiseer word. Die kleur van Mu Cephei is opgemerk deur William Herschel, wat dit beskryf het as & # 8220a rooi en diep kleur & # 8221.
9. 72 Leonis
72 Leonis woon in die konstellasie Leo. Dit is 'n rooi helder reuse-ster met 'n helderheid van 'n oënskynlike grootte van 4,56. Sy geprojekteerde Galaktiese baan dra dit tussen 21 200 en 25 300 ligjare vanaf die middel van die Melkweg. Dit beweeg teen 'n snelheid van 37,4 km / s relatief tot die son.
10. V509 Cassiopeiae
V509 Cassiopeiae-hyperreus is 'n geel-wit F-ster met 'n skynbare magnitude van +5,10 in die sterrebeeld Cassiopeia. 10 & # 8211 V509 Cassiopeiae (V509 Cas) is 'n ster in die sterrebeeld Cassiopeia.
V509 Cassiopeiae-hyperreus is 'n geel-wit F-ster met 'n skynbare grootte van +5,10. Is ongeveer 7800 ligjare van die aarde af. Dit word geklassifiseer as 'n halfreëlmatige veranderlike ster en die helderheid daarvan wissel van grootte +4,75 tot +5,5.
11. Theta Muscae
Theta Muscae (θ Mus, Muscae θ) is 'n drievoudige sterrestelsel in die sterrebeeld Musca.
Met 'n gesamentlike skynbare grootte van 5,53,1 is dit net met die blote oog sigbaar onder uitstekende kykomstandighede. Maar die primêre komponent daarvan is die tweede helderste ster in die lug Wolf-Rayet (die tweede na Gamma Velorum).
Wolf-Rayet-sterre is blou superreuse in 'n gevorderde stadium van evolusie wat hul buitenste lae verloor het en swaar kernelemente uitstraal, veral koolstof hierdie geval, afgesien van 'n sterk sterwind.
Theta Muscae is te ver van die aarde af om die afstand te meet volgens die parallaksmetode, maar hierdie waarde is geskat op ongeveer 7 500 ligjare (2300 stuks).
Hierdie drievoudige sterstelsel bestaan uit 'n spektroskopiese binêre en verste blou superreus. 'N Spektroskopiese binêre word gevorm deur die Wolf-Rayet-ster van die spektraaltipe WC5 / 6, en 'n ster van die klas van die hoofreeks-spektraaltipe O6 / O7V. Hulle word met 0,5 AE geskei en voltooi elke 19.14 dae 'n baan. 46 millisekondes van die boog (wat ooreenstem met 100 AE) van die paar is die blou superreus, wat die spektrale tipe O9.5 / B0Iab het.
Die drie sterre is baie helder en het waarskynlik meer as een miljoen keer die helderheid van die son.
Almal het meer as tien keer die sonmassa en kan dus hul lewens as supernovas beëindig.
12. V838 Monocerotis
V838 Monocerotis is 'n rooi oormatige ster in die sterrebeeld Monoceros, met 'n skynbare grootte van +15,74. Dit word aangedui as een van die vreemdste sterre van die Melkweg, en een van die helderste van ons Melkweg. Dit is 'n veranderlike ster, op 'n afstand van ongeveer 20 000 ligjaar vanaf die son (6 kpc). Het in 2002 'n ernstige uitbarsting gehad. Oorspronklik was dit 'n tipiese nova. As gevolg van die uitbarstings, is dit heeltemal verander. Daar is verskeie uitbarstings gevolg, waaronder 'n sterre-uitbarsting wat 'n sterfteproses aanmeld, en saamgevoeg van 'n binêre ster of planete.
13. V382 Carinae
V382 Carinae, ook bekend as die Bayer-benaming x Carinae (Car x), is 'n ster in die sterrebeeld Carina. Dit is 5930,90 ligjare van die aarde af geleë. Hierdie ster word geklassifiseer as 'n Cepheid-veranderlike ster en die helderheid daarvan wissel van grootte +3,84 tot +4,02.
14. Antares (α Scorpii, Alpha Scorpii)
Antares (α Scorpii, Alpha Scorpii) is 'n rooi reuse-ster in die sterrebeeld Scorpius. Dit is die 16de helderste ster aan die naghemel (hoewel dit soms as die 15de beskou word, as die twee helderste komponente van die ster Capella as een ster gereken word). In kombinasie met Aldebaran, Spica en Regulus, is Antares een van die vier helderste sterre naby die ekliptika. Antares is 'n ster met stadige wisselvalligheid met 'n skynbare grootte van +1,09.
15. Alpha Orionis (α Orionis)
Alpha Orionis (α Orionis), bekend as Betelgeuse, is 'n ster met veranderlike helderheid en is die 10de of 12de helderste ster in die uitspansel. Dit is ook die tweede helderste ster in die Orion-konstellasie. Ondanks die benaming α (& # 8220alpha & # 8221), is dit volgens Rating Bayer nie so helder soos Rigel (β Orionis) nie.
Betelgeuse is eintlik helderder as Rigel in infrarooi golflengte, maar nie in die sigbare golflengtes nie.
16. S Pegasi (S Peg)
S Pegasi (S Peg) is 'n langtermyn-veranderlike Mira wat 319,22 dae per periode neem. Dit het 'n wye sterkte van 8-13 en het 580 keer die radius van ons son. Dit is geleë in die konstellasie van Pegasus.
17. S Doradus
S Doradus is die helderste ster in die Groot Magellaanse Wolk, 'n satellietstelsel van die Melkweg. Om 'n hipergigant te wees, is een van die bekendste sterre wat bekend is (iets helderder as die absolute grootte -10, maar is so ver weg dat onsigbaar is met die blote oog).
Ons kan dit in die uiterste noordelike lug in die sterrebeeld Dorado vind, regs hemelvaart 5u 18,2 m, deklinasie -69 ° 15 & # 8216.
Hierdie ster behoort tot sy eie gelyknamige klas veranderlike sterre, die S Doradus (hierdie klasse word gewoonlik gedoop met die naam van hul prototipes), ook genoem LBV (helderblou veranderlike).
S Doradus het lang en stadige helderheidsvariasies in 'n siklus van 40 jaar, wat deur af en toe uitbarstings onderdruk word.
18. T Cephei
T Cephei is 'n rooi reuse-ster in die Cepheus-konstellasie, 685,22 jaar lig van die aarde af.
Dit is 'n Mira-tipe veranderlike, baie rooi, waarvan die helderheid tussen ongeveer 5,40 en 10,9 op ongeveer 388,1 dae wissel. Dit is 'n ster van die spektrale klas M, waarvan die radius 540 keer groter is as ons son.
Vergaderingkoördinate: Lat: 88.346 °, Lang: -47.756 °
Dit het 'n rotasiesnelheid van 20 km / s en 'n radiaal van -3,4 km / s.
19. S Orionis (S Ori)
S Orionis (S Ori) is 'n rooi reuse-ster in die Orion-konstellasie. Dit is 'n veranderlike Mira-ster, met 'n siklus van 420 dae, en die radius daarvan wissel van 1,9 tot 2,3 sterrekundige eenhede.
20. Gamma Velorum (ou Regor)
Gamma Velorum is 'n sterstelsel in die konstellasie van Vela. Met 'n skynbare grootte van +1,75 is dit een van die blinkste sterre aan die naghemel. Het ander eiename soos Suhail of Al Suhail al-Muhlif (moet nie verwar word met die naam Suhail nie, wat ook ander sterre soos Lambda Velorum kan wees).
Sy gewildste naam is Regor, wat die teenoorgestelde van Roger is, ter ere van die ruimtevaarder Roger Chaffee. Dit is ongeveer 813 ligjaar van ons son geleë.
Dit is 'n stelsel wat deur ses sterre gevorm word. Die helderste lid, γ ² Velorum of γ Velorum A, is tans 'n spektroskopiese binêre wat bestaan uit 'n blou superreus van die spektrale tipe O9 (30 M ☉), en 'n massiewe ster Wolf-Rayet-ster, die swaarste bekend (10 M ☉, oorspronklik byna 40 M ☉). Die binêre het 'n wentelperiode van 78,5 dae en 'n skeiding van 1 AU.
Gamma Velorum het 'n metgesel, die helder (skynbare grootte +4.2) ¹ γ Velorum of γ Velorum B, dit is 'n blou-wit subreus van die spektrale tipe B. Dit word van 41.2 & # 8220 van die binêre Wolf-Rayet geskei, en hul afstand kan met 'n verkyker waargeneem word.
Sterretyd
Die verskeidenheid horlosies wat ontwerp is om die minute van ons lewens te meet, is verbasend. Genieë, pragmatiste en kraakpotte het toestelle groot en klein ontwikkel om die reis van die son deur die lug aan te dui. Sonduur, uurglas, geykte kerse en selfs uitgebreide wierookhorlosies het daaglikse gebede, werksure en etenstye gereguleer. 'N Egiptiese farao is begrawe met 'n waterklok wat omstreeks 1500 vC ontwerp is, wat moderne ingenieurs steeds met sy slim in- en uitvloei om die tyd te bepaal, intrigeer. Die Grieke het omstreeks 325 vC hul eie weergawe van die waterklok ontwikkel, genaamd clepsydra of "waterdief", en gebruik dit om toesprake in die geregshowe uit te voer.
Mettertyd het kleiner weergawes van horlosies in die gange van die landgoed begin verskyn, op die mantels van privaat huise, in die sakke van ryk mans en uiteindelik aan die polse van byna almal wat 'n Timex, Seiko of Pulsar kon bekostig. Die slimhorlosie is du jour, maar wie weet wat volgende gaan kom. Die oudste chronograaf sweef egter nog steeds bokant ons, en sy vonkelende gesig is die beste sigbaar op helder nagte en vanaf afgeleë bergtoppe. Die sterhorlosie is 'n 24-uur horlosie wat agtertoe loop gebaseer op noordelike sterre en 'n bietjie rekenkunde benodig om op die regte tyd te kom, maar dit loop nooit af nie, dit breek nooit en kan gebruik word deur almal met 'n ietwat ordentlike uitsig die naghemel.
2 – Find the two “pointer stars” which are the two stars where any liquid would run out of the bottom of the dipper.
3 – Follow the straight line of the two “pointer stars” five times the distance between those stars to locate the North Star.
4 – The North Star is the center of the star clock.
5 – The star clock has only one hand, formed by imagining a straight line that runs from the North Star and through the two “pointer stars” in the Big Dipper.
6 – The clock moves counterclockwise and measures 24 positions. At the top is midnight. The position one quarter to the left which would be 9:00 on a traditional clock is actually 6:00 AM on the star clock. The bottom of the clock is 12:00 noon.
7 – The star clock also runs 4 minutes faster than the sun each day, so it requires some math to get at an accurate reading.
8 – On March 7 th of each year the clock tells the correct time. For every week after March 7 subtract half an hour and for every week before March 7 add half an hour.
9 – If it is Daylight Savings Time add one more hour.
Suppose today is September 14 th . The pointer stars in the Big Dipper are in a straight line below the North Star. This would be noon on the star clock. However, the clock reading is fast by one-half hour for six months and one week, or twelve and a half hours. Moving back twelve and a half hours from noon puts the time at 11:30 p.m. Considering that September is still in Daylight Savings Time one hour is added back onto the clock. This makes the time 12:30 a.m. or half past midnight on a traditional clock.
As soon as it’s dark enough, go outside and determine the position of the North Star and the pointer stars in the Big Dipper. Check the date. Do the math. Does the time on the star clock match the time on your wristwatch or smartphone? They should be close.
Our reasons for measuring time have evolved over the years, but mostly it’s been for the purposes of coordination, for gathering together at the intersection of a specific time and place. It’s kind of a cosmic “You Are Here” sign. There are a gazillion ways to measure time, to subdivide it and record it, but perhaps what matters most is what ons do with it as the stars slide around the great circle of the sky above us.
And for those worried about the end of time, Charles Schulz offered reassurance through the ever sensible Marcie in his June 13, 1980 cartoon strip. “I promise there’ll be a tomorrow, sir,” Marcie says, “in fact, it’s already tomorrow in Australia.”
Quasi star compared to uy scuti
She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. Below is a list of the largest stars, so far discovered, ordered by radius. It’s a pulsating star that swells and shrinks periodically, usually shining about 400,000 times brighter than our Sun. It is bigger than UY Scuti and my Cheese Star, but smaller than Quasi-star. UY Scuti vs Sun. Scudder said: This star is one of a class of stars that varies in brightness because it varies in size, so this number is also likely to change over time. This thread is archived. In this article, we are going to examine the biggest known stars, dig into how they are discovered and what the challenges are in measuring their size, and compare the giant stars of UY Scuti and VY Canis Majoris to Earth and our star… In a closely packed star cluster, double-stars are more likely to encounter each other and merge. At an estimated 1,540 times the sun’s radius, this star is thought to be the largest star in the Large Magellanic Cloud, in terms of sheer physical size. However all the stars mentioned are tiny compared to Quasi-stars. However, the star was better documented in 2012 with the help of greater technological equipment. Size comparison of a hypothetical quasi-star/black hole star (diameter of
7,187 solar diameters, mass of 1000+ solar masses) and several known giant stars: UY Scuti (
7-10 solar masses), VY Canis Majoris (
17 solar masses), Betelgeuse (
11.6 solar masses), the Pistol Star (
306 solar … UY Sct is a dust-enshrouded bright red supergiant and is classified as a semiregular variable with an approximate pulsation period of 740 days. And, again, we’re talking size here, not mass.
Star Types
Some of the images of stars below include text, HUD elements, or portions of ships within the image itself. These images should be replaced with clean images that display only the relevant stars.
Main Sequence Stars (O, B, A, F, G, K, M)
77% Ώ] of all stars this category can be considered Very Common. ΐ]
Class O star systems rarely contain terrestrial bodies. One of the most likely to host a stellar nursery.
Class B star systems rarely contain terrestrial bodies. One of the most likely to host a stellar nursery.
Class A star systems often contain high metal content worlds and metal-rich bodies.
Class F star systems are one of the most likely to contain Earth-like worlds.
Class G star systems are one of the most likely to contain Earth-like worlds.
Class K star systems are the most likely to contain water worlds and rocky bodies.
Class M star systems tend to contain many icy bodies and rocky ice worlds.
Giants and Supergiants
0.25% Ώ] of all stars this category can be considered Very Rare. ΐ]
Proto Stars (Herbig Ae/Be, TTS)
2.4% Ώ] of all stars this category can be considered Rare. ΐ]
Herbig Ae/Be stars are more common nearer the galactic core.
Take caution when travelling and using a fuel scoop, as the TTS' appearance often resembles M or K stars.
Carbon Stars (C, CH, CHd, CJ, CN, CS, MS, S)
0.08% Ώ] of all stars this category can be considered Very Rare. ΐ]
Wolf-Rayet Stars (W, WC, WNC, WNC, WO)
0.05% Ώ] of all stars this category can be considered Very Rare. ΐ]
Example system with yellow color is Dryaa Flyuae AA-A H254.
Black Holes
0.41% Ώ] of all stars this category can be considered Very Rare. ΐ]
Less likely to be found nearer the edge of the galactic plane.
Take great caution when approaching a supermassive black hole, as unlike other smaller black holes, a supermassive black hole will cause rapid heat build-up if approached too closely, causing significant ship damage. Sagittarius A* is currently the only known Supermassive Black Hole in the game.
Neutronsterre
4.0% Ώ] of all stars this category can be considered Rare. ΐ]
Take caution when approaching these stars, as they are so tiny they are almost invisible. They still radiate heat, and getting closer than 0.25Ls will cause one's heat to build up. If you fly with your ship into the emitted energy cloud your FSD will be supercharged and the jump range for the next jump will be dramatically increased. However, dropping out of supercruise while within a neutron star's jet is incredibly dangerous, as incredibly fast particles of ionized matter will tear through your ship's hull and systems. Take special care when supercharging to ensure that you do not fly too close to the star, or your ship may be heavily damaged/destroyed after performing an emergency drop. More common near the center of the galaxy.
White Dwarfs (D, DA*, DB*, DC*, DO*, DQ, DX)
0.36% Ώ] of all stars this category can be considered Very Rare. ΐ]
White dwarfs (category D for degenerate) are the collapsed core of a star that has lost a large proportion (
20%) of its original mass as the ejected material of a planetary nebula or in a supernova explosion, the terminal stages of stellar evolution. White dwarfs are not stars because they no longer sustain nuclear fusion, and lacking this interior thermal source of support the star has gravitationally collapsed to a very small radius. White dwarfs glow with the residual heat of the degenerate core, which can have a temperature well above 100,000 K at collapse and that cools over several billion years. Class D is further divided into spectral types Δ] that indicate the elemental composition of the photosphere.
- DA: strong Balmer series hydrogen absorption lines only no helium or metals present.
- DB: strong He I (neutral helium) absorption lines only no hydrogen or metals present.
- DC: a continuous (blackbody) spectrum with no absorption lines deeper than 5% in any part of the electromagnetic spectrum.
- DO: strong lines of He II (ionized helium) with molecular hydrogen or helium present.
- DQ: carbon absorption lines, either atomic or molecular, in any part of the electromagnetic spectrum.
- DZ: metal (elements heavier than helium) absorption lines in the absence of both hydrogen and helium lines.
Symbols Appended to the Above Designations
- P: magnetic white dwarfs with detectable polarization.
- H: magnetic white dwarfs without polarization.
- X: peculiar or unclassifiable spectrum.
- E: emission lines (of any element) present.
- ?, :: uncertain classification.
- V: variable luminosity.
- d: circumstellar dust.
- C I, C II, O I, O II added within parentheses to indicate the presence of these elements in DQ objects.
The current practice is to append numerical indicators of the white dwarf temperature and surface gravity, separated by an underline "_". Temperature is indicated as the effective surface temperature divided into 50400 and rounded to the first decimal place, e.g. DA.9 = 56000 K and DB1.2 = 42000 K. Gravity is assessed as the width of the dominant spectral lines and the log values range from 7 to 9.
The table below shows the white dwarf subtypes within Elite Dangerous. These do not necessarily match the notation mentioned above (for example, ED uses DAZ which probably should be DZ) but comes very close. The "Rarity" column indicates the subtype rarity within the White Dwarfs spectrum.
Take caution when approaching these stars, as their sphere of influence is surprisingly large for their size.
Brown Dwarfs (L, T, Y)
15% Ώ] of all stars this category can be considered Common. ΐ]
Class L star systems tend to contain many icy bodies.
Class T star systems tend to contain many icy bodies.
Class Y star systems tend to contain many icy bodies. Take caution when exiting a hyperspace jump into a Y-Class star system, as the humble appearance of these star types can cause one to fly too close to the star, hitting the body exclusion zone and triggering an emergency drop from supercruise.
Undiscovered Star Types
These classes are mentioned in the Journal documentation, Β] but none have been submitted to EDSM yet.
| Beeld | Class Β] | Fuel-Scoopable | Rarity Within Type | Description / Notes |
|---|---|---|---|---|
| Exotic | None found/reported yet. | |||
| Newel | Some systems, when searched for in the galaxy map, will result in the selection of a correspondingly named nebula, which was presumably once the system that was searched for. | |||
| Rogue Planet | None found/reported yet. | |||
| Stellar Remnant Nebula | None found/reported yet. |
Related Research Articles
A supernova is a powerful and luminous stellar explosion. This transient astronomical event occurs during the last evolutionary stages of a massive star or when a white dwarf is triggered into runaway nuclear fusion. The original object, called the progenitor, either collapses to a neutron star or black hole, or is completely destroyed. The peak optical luminosity of a supernova can be comparable to that of an entire galaxy before fading over several weeks or months.
Supergiants are among the most massive and most luminous stars. Supergiant stars occupy the top region of the Hertzsprung–Russell diagram with absolute visual magnitudes between about and . The temperature range of supergiant stars spans from about 3,400 K to over 20,000 K.
In astronomy, a blue giant is a hot star with a luminosity class of III (giant) or II. In the standard Hertzsprung–Russell diagram, these stars lie above and to the right of the main sequence.
A blue supergiant (BSG) is a hot, luminous star, often referred to as an OB supergiant. They have luminosity class Ek and spectral class B9 or earlier.
A giant star is a star with substantially larger radius and luminosity than a main-sequence star of the same surface temperature. They lie above the main sequence on the Hertzsprung–Russell diagram and correspond to luminosity classes II en III. The terms giant en dwarf were coined for stars of quite different luminosity despite similar temperature or spectral type by Ejnar Hertzsprung about 1905.
Die asymptotic giant branch (AGB) is a region of the Hertzsprung–Russell diagram populated by evolved cool luminous stars. This is a period of stellar evolution undertaken by all low- to intermediate-mass stars late in their lives.
Die red-giant branch (RGB), sometimes called the first giant branch, is the portion of the giant branch before helium ignition occurs in the course of stellar evolution. It is a stage that follows the main sequence for low- to intermediate-mass stars. Red-giant-branch stars have an inert helium core surrounded by a shell of hydrogen fusing via the CNO cycle. They are K- and M-class stars much larger and more luminous than main-sequence stars of the same temperature.
A subgiant is a star that is brighter than a normal main-sequence star of the same spectral class, but not as bright as giant stars. The term subgiant is applied both to a particular spectral luminosity class and to a stage in the evolution of a star.
Luminous blue variables (LBVs) are massive evolved stars that show unpredictable and sometimes dramatic variations in both their spectra and brightness. They are also known as S Doradus variables after S Doradus, one of the brightest stars of the Large Magellanic Cloud. They are extraordinarily rare with just 20 objects listed in the General Catalogue of Variable Stars as SDor, and a number of these are no longer considered to be LBVs.
A yellow hypergiant (YHG) is a massive star with an extended atmosphere, a spectral class from A to K, and, starting with an initial mass of about 20 solar masses, has lost as much as half that mass. They are amongst the most visually luminous stars, with absolute magnitude (MV) around , but also one of the rarest, with just 15 known in the Milky Way and six of those in just a single cluster. They are sometimes referred to as cool hypergiants in comparison with O- and B-type stars, and sometimes as warm hypergiants in comparison with red supergiants.
A yellow supergiant (YSG) is a star, generally of spectral type F or G, having a supergiant luminosity class. They are stars that have evolved away from the main sequence, expanding and becoming more luminous.
S Persei is a red supergiant or hypergiant located near the Double Cluster in Perseus, north of the cluster NGC 869. It is a member of the Perseus OB1 association and one of the largest known stars. If placed in our solar system, its photospehere would engulf the orbit of Jupiter. It is also a semiregular variable, a star whose variations are less regular than those of Mira variables.
VY Canis Majoris is an extreme oxygen-rich (O-rich) red hypergiant (RHG) or red supergiant (RSG) and pulsating variable star 1.2 kiloparsecs from the solar system in the slightly southern constellation of Canis Major. It is one of the largest known stars, is one of the most luminous and massive red supergiants, as well as one of the most luminous stars in the Milky Way.
A hypergiant (luminosity class 0 of Ia + ) is a very rare type of star that has an extremely high luminosity, mass, size and mass loss because of their extreme stellar winds. Die term hypergiant is defined as luminosity class 0 (zero) in the MKK system. However, this is rarely seen in the literature or in published spectral classifications, except for specific well-defined groups such as the yellow hypergiants, RSG (red supergiants), or blue B(e) supergiants with emission spectra. More commonly, hypergiants are classed as Ia-0 or Ia + , but red supergiants are rarely assigned these spectral classifications. Astronomers are interested in these stars because they relate to understanding stellar evolution, especially with star formation, stability, and their expected demise as supernovae.
A red giant is a luminous giant star of low or intermediate mass in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius large and the surface temperature around 5,000 K or lower. The appearance of the red giant is from yellow-orange to red, including the spectral types K and M, but also class S stars and most carbon stars.
RMC 136a1 is one of the most massive and luminous stars known, at 215 M ☉ and 6.2 million L ☉ , and is also one of the hottest, at around 46,000 K . It is a Wolf–Rayet star at the center of R136, the central concentration of stars of the large NGC 2070 open cluster in the Tarantula Nebula in the Large Magellanic Cloud. The cluster can be seen in the far southern celestial hemisphere with binoculars or a small telescope, at magnitude 7.25. R136a1 itself is 10,000 times fainter and can only be resolved using speckle interferometry.
PZ Cassiopeiae is a red supergiant star located in the Cassiopeia constellation, and a semi-regular variable star.
HD 179821 of V1427 Aquilae is either a post-red supergiant yellow hypergiant or a post-AGB yellow supergiant star in the constellation of Aquila, surrounded by a detached dust shell. It is a semi-regular variable nearing the end of its life.
An O-type star is a hot, blue-white star of spectral type O in the Yerkes classification system employed by astronomers. They have temperatures in excess of 30,000 kelvin (K). Stars of this type have strong absorption lines of ionised helium, strong lines of other ionised elements, and hydrogen and neutral helium lines weaker than spectral type B.
A super-AGB star is a star with a mass intermediate between those that end their lives as a white dwarf and those that end with a core collapse supernova, and properties intermediate between asymptotic giant branch (AGB) stars and red supergiants. They have initial masses of 7.5.25 M ☉ in stellar-evolutionary models, but have exhausted their core hydrogen and helium, left the main sequence, and expanded to become large, cool, and luminous.
We found at least 10 Websites Listing below when search with vy canis majoris supernova on Search Engine
A hypergiant star's mysterious dimming Space EarthSky
Earthsky.org DA: 12 PA: 50 MOZ Rank: 62
While scientists generally think that VY Canis Majoris will eventually explode in a supernova, there’s also a chance it may turn directly into a black hole instead, skipping the supernova …
VY Canis Majoris mass-loss history sheds light on
- And this would make sense given that both Betelgeuse and VY Canis Majoris are predicted to go supernova within 100,000 years
When will VY Canis Majoris be expected to be a supernova
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- It has been shedding tons of material
- It’s an incredibly massive star, 30 to 40 times more massive than our sun, about 300,000 times brighter, about 1,800 to 2,000 times larger in radius
- Hypergiants don’t last very long (relative
Hypergiant Red Star VY Canis Majoris Is Going To Die Soon
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- VY Canis Majoris is going to continue “dieting” until the end
- Its end will come as a violent supernova explosion, which should happen, cosmologically speaking, very soon
- Maybe in a thousand year or, maybe, in a few hundred thousand
Red Hypergiant Could Explain What's up With Betelgeuse
- But on VY Canis Majoris, the cells may be as large as the whole sun or larger
- “This is probably more common in red supergiants than scientists thought and VY Canis Majoris …
5 Better Candidates Than Betelgeuse For Our Galaxy’s Next
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- Today we see the Crab Nebula as the expanding gaseous remnant from a star that self-detonated as a supernova, briefly shining as brightly as 400 million suns
The Hypernova of VY Canis Majoris
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Hubble Solves Mystery of Monster Star's Dimming
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- VY Canis Majoris may have already shed half of its mass
- Rather than exploding as a supernova, it might simply collapse directly to a black hole
- The team's findings appear in the February 4, 2021 edition of The Astronomical Journal .
The Short, Violent Life of a Red Hypergiant Star
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VY Canis Majoris, one of the largest known stars in the Milky Way and 300,000 times brighter than our Sun, “is behaving a lot like Betelgeuse on steroids,” said astrophysicist Roberta
VY Canis Majoris Facts, Information, History & Definition
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- VY Canis Majoris is a red supergiant/hypergiant star of spectral type M3-M4.5
- It is an extreme oxygen-rich and pulsating variable star
- It has an apparent magnitude that varies from 6.5 to - 9.6, and its absolute magnitude is – 9.4
- This hypergiant is losing its mass to a rate of around 30 times the mass of Earth every single year.
VY Canis Majoris is "Like Betelgeuse on Steroids
- VY Canis Majoris is “Like Betelgeuse on Steroids”
- The disappearance of a star can take many forms
- It could turn into a black hole
- Or it could just fade away quietly
NML Cygni – The Largest Star We Currently Know of in the
- However, this video was made before the NML Cygni was discovered and shows the VY Canis Majoris as the largest known star, which it was at the time this video was made
- Die VY Canis Majoris is 1,420 times larger than our Sun (and again, the …
VY Canis Majoris in process of going supernova, it'll
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Dec 7, 2012 - VY Canis Majoris in process of going supernova, it'll collapse on its huge size and density to infinite mass and energy turning itself to a black hole, with no escape, not even light.
The Hypernova of VY Canis Majoris
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- The reason for this mass loss is poorly understood, but it is believed to be due instabilities in the interior and exterior layers of the star
- These instabilities are usually the progenitor of a supernova
- VY Canis Majoris has already shed over half of its original mass
- It is in the final throes of death and could explode at literally, any time.
VY Canis Majoris (Supergiant Star) Star Facts
- VY Canis Majoris estimated radius has been calculated as being 188.25 times bigger than the Sun
- The Sun's radius is 695,800km, therefore the star's radius is an estimated 130,982,082.14.km
- If you need the diameter of the star, you just need to multiple the radius by 2
- The figure is derived at by using the formula from SDSS rather than peer
The Red Hypergiant VY CMa – Betelgeuse on Steroids
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- VY Canis Majoris may have already shed half of its mass
- Rather than exploding as a supernova, it might simply collapse directly to a black hole
- The team’s findings appear in the February 4, 2021 edition of The Astronomical Journal
- Authors includeSchool of Physics and Astronomy Professors Kris Davidson and Terry Jones and former University
Gedetailleerde beelde van die Hypergiant Star VY Canis Majoris
- VY Canis Majoris is a stellar goliath, a red hypergiant, one of the largest known stars in the Milky Way
- It is 30–40 times the mass of the Sun and 300,000 times more luminous
- In its current state, the star would encompass the orbit of Jupiter, having expanded tremendously as …
Bad Astronomy Betelgeuse has nothing on VY CMa, which
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- But in this case we're talking about the star VY Canis Majoris (of VY CMa for short)
- This ridiculously bloated red hypergiant is about 4,000 light years away in the constellation of Canis Major, the Big Dog (one of Orion's hunting dogs)
- In this case, the constellation is appropriate: VY CMa is an immense star, well over 2 billion kilometers wide.
- For comparison, the Sun is 1.4 million km
Hypergiant Star Is Dropping 30 Earthloads Of Dust A Year
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Astronomers have discovered that the hypergiant star VY Canis Majoris is shedding 30 Earthloads of dust a year in a massive weight loss programme before it goes supernova…
The future of VY Canis Majoris -- Astronomy.info
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Earth Size Compared to Sun Graphic
- Astronomers expect VY Cani Majoris to go supernova within the next 100,000 years
- Here's how VY Canis Majoris compares to Betelgeuse (in …
Red Supergiants as Potential Type IIn Supernova
- We present high-resolution 4.6 μm CO spectra of the circumstellar environments of two red supergiants (RSGs) that are potential supernova (SN) progenitors: Betelgeuse and VY Canis Majoris (VY CMa)
- Around Betelgeuse, 12 CO emission within ۭ'' (䔰 km s -1 ) follows a mildly clumpy but otherwise spherical shell, smaller than its
The Hypernova of VY Canis Majoris on Vimeo
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A giant star in deep space is obscured by dust
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A huge star 300,000 times brighter than the Sun is nearing the end of its life and shrouding itself with dust, according to new data from the Hubble Space Telescope.Why it matters: Learning more about this star — named VY Canis Majoris — will help astronomers piece together how stars much larger than the Sun evolve and behave at the ends of their stellar lives.Stay on top of the …
VY Canis Majoris is Enshrouded in Giant Dust Clouds
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- VY Canis Majoris is located 3,840 light-years away in the constellation of Canis Major
- Also known as VY CMa, HD 58061 or HIP 35793, VY Canis Majoris…
Red hypergiant mimics Betelguese with dusty dimming on a
- Zooming into VY Canis Majoris: The left panel is an image captured by the Hubble Space Telescope showing the trillion-mile-wide nebula of debris ejected from the hypergiant
- The middle image is a close-up view from Hubble showing the star’s immediate surroundings (the red dot indicates the star’s location, representing the size of Earth’s
Hubble Space Telescope Imaging of the Mass-losing
- The highly luminous M supergiant VY CMa is a massive star that appears to be in its final death throes, losing mass at high rate en route to exploding as a supernova
- Subarcsecond-resolution optical images of VY CMa, obtained with the Faint Object Camera (FOC) aboard the Hubble Space Telescope, vividly demonstrate that mass loss from VY CMa is highly anisotropic.
Sterre swaargewigte: VY Canis Majoris
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As for VY Canis Majoris, we can only wait and see what will happen, but it is thought that the spectacle would shine so brightly that we would be able to see it during daytime here on Earth.
Are stars NML Cygni, UY Scuti, VY Canis Majoris and VV Cephei near the ends of their lives? - Sterrekunde
Yes it is, just like the default in every question of whether or not something exists is "no". The burden of proof is on the side claiming that the thing exists. If I say "there is an invisible unicorn in your room" the appropriate response is "prove it", and to not believe in the unicorn until I meet that demand for proof. And when I inevitably fail to do so the appropriate belief is "there is no unicorn". If I responded with "but 'no unicorn' isn't the default position" you'd just laugh at me and continue holding the only reasonable belief: that there is no unicorn. The only reason we don't treat your god the same way as the unicorn is that there are a lot of religious people who really want their beliefs to be true and demand special treatment for them.
Actually, I must agree with Peregrine here. Atheism, or at least agnosticism is the default position for people. When you're born, you aren't born a Christian, Muslim, (practicing) Jew, Hindu or any other religion. You MUST be taught religion and faith. Usually, this is done in a rather forced manner by parents and other close relatives.
I went to Sunday school, etc., church stuff as a kid. My parents didn't. It wasn't forced on me. I wanted to go. But I started asking questions and getting answers that weren't actually answers. The other kids didn't understand how those answers didn't make sense to me. I realized at a very young age that we were being conditioned into these beliefs, and my skepticism of "the truth" was actually negatively impacting how my peers viewed me. Innocent, real questions getting handwaving answers or straight up "are you stupid" answers wasn't good enough for me.
Edit here: My grandma was actually the reason I did those things. She used to tell me about being a Christian and their God and everything, and she inspired me to check it out.
On the "people getting better" points. Why those people in your anecdotes? What do they matter in the scheme of things? Why do you believe a certain mother can take the sickness from their child, but another is forced to watch her child die a slow, painful, agonizing death? Is one mother a better person? Is it just because she believes harder? I've never understood how people point to adults getting healthier suddenly and saying it's evidence of a deity while ignoring completely the fact that the same deity is ignoring children starving to death or dying of incredibly ugly diseases. Who knows, maybe they deserve it for being born in the wrong country. Unless you want to say that both are evidence of a deity. Which I would respond to by saying that it's no deity that deserves any kind of worship.
I honestly believe polytheism has a lot more merit than monotheism, because then at least it can be that one deity is killing children while another is running around curing adults that go on to do nothing more significant than anyone else with their lives.
This message was edited 1 time. Last update was at 2016/07/29 14:29:48
