View source for M33-013406.63

{{Short description|Star in the constellation of Triangulum}}
{{Starbox begin
 | name = M33-013406.63
}}
{{Starbox image
 | image = {{CSS image crop
|Image         = [[File:M33-013406.63 Pan-STARRS.jpg]]
|bSize         = 1806
|cWidth        = 300
|cHeight       = 300
|oTop          = 232
|oLeft         = 752}}
 | caption = M33-013406.63 (brightest star at the center) by [[Pan-STARRS]] Data Release 1 in blue, g, and r filters.
 | credit = [[NASA]]/[[University of Hawaiʻi|UH]]-[[Institute for Astronomy (Hawaii)|IfA]]
}}
{{Starbox observe
 | epoch = [[J2000.0]]
 | constell = [[Triangulum]]
 | ra = {{RA|01|34|06.63}}<ref name=hipparcos>{{cite journal|bibcode=2007A&A...474..653V|title=Validation of the new Hipparcos reduction|journal=Astronomy and Astrophysics|volume=474|issue=2|pages=653–664|last1=Van Leeuwen|first1=F.|year=2007|doi=10.1051/0004-6361:20078357|arxiv = 0708.1752 |s2cid=18759600}}</ref>
 | dec = {{DEC|+30|41|37.60}}<ref name=hipparcos/>
 | appmag_v = 16.1<ref name=kournioitis2018/>
}}
{{Starbox character
 | class = O<ref name=humphreys/>
 | type = Late [[Blue supergiant star|O supergiant]] or candidate [[luminous blue variable|LBV]]<ref name=humphreys/>
 | variable = [[luminous blue variable|cLBV]]?<ref name=humphreys/>
}}
{{Starbox astrometry
| dist_ly =
| dist_pc = 
| absmag_v = –9.1 – –9.6<ref name=humphreys/>
| absmag_bol = –12.2 – –12.7<ref name=humphreys/>
}}
{{Starbox detail
| source=<ref name=kournioitis2018>{{cite journal |bibcode=2018MNRAS.480.3706K |title=On the evolutionary state of massive stars in transition phases in M33 |last1=Kourniotis |first1=M. |last2=Kraus |first2=M. |last3=Arias |first3=M. L. |last4=Cidale |first4=L. |last5=Torres |first5=A. F. |journal=Monthly Notices of the Royal Astronomical Society |year=2018 |volume=480 |issue=3 |page=3706 |doi=10.1093/mnras/sty2087 |doi-access=free |arxiv=1808.00008 }}</ref>
| component1 = A
| mass = 
| luminosity = {{val|4.68|e=6}}
| radius = 80{{efn|name=radius1}}
| temperature = ~30,000
| gravity = 
| metal_fe =
| rotational_velocity = {{val|75|5}}
| age_myr =
| component2 = B
| mass2 = 
| luminosity2 = 407,380
| radius2 = 210{{efn|name=radius2}}
| temperature2 = 10,000
| gravity2 = 
| metal_fe2 =
| rotational_velocity2 =
| age_myr2 =
}}
{{Starbox catalogue
| names=LGGS J013406.63+304147.8, B416
}}
{{Starbox reference
| Simbad = %5BHS80%5D+B416
}}
{{Starbox end}}

'''M33-013406.63''', also known as '''B416''' or '''UIT301''',<ref>{{Cite journal|last1=Humphreys|first1=R. M.|last2=Sandage|first2=A.|date=November 1980|title=On the stellar content and structure of the spiral Galaxy M33|journal=The Astrophysical Journal Supplement Series|volume=44|pages=319|doi=10.1086/190696|bibcode=1980ApJS...44..319H|issn=0067-0049}}</ref> is a O-type blue evolved [[supergiant star]] in the [[constellation]] of [[Triangulum]]. It is located within the [[Triangulum Galaxy]], which is approximately 2,380,000–3,070,000 light years away from [[Earth]].

It is potentially one of the [[List of most luminous stars|most luminous stars]] ever discovered, estimated to be approximately between 3 and 10 million times more luminous than the [[Sun]], although it is thought likely to be a [[Star system|multiple star system]].<ref name=humphreys>{{cite journal |doi=10.1088/0004-637X/790/1/48 |title=Luminous and Variable Stars in M31 and M33. II. Luminous Blue Variables, Candidate LBVs, Fe II Emission Line Stars, and Other Supergiants |year=2014 |author-link1=Roberta M. Humphreys|last1=Humphreys |first1=Roberta M. |last2=Weis |first2=Kerstin |last3=Davidson |first3=Kris |last4=Bomans |first4=D. J. |last5=Burggraf |first5=Birgitta |journal=The Astrophysical Journal |volume=790 |issue=1 |pages=48 |arxiv=1407.2259 |bibcode=2014ApJ...790...48H |s2cid=119177378 }}</ref>  Modelling of the spectrum based on some assumptions about the relative sizes of the two [[Star|stars]] suggests a secondary around half a million times as luminous as the [[Sun]] and the primary over four million times as luminous as the [[Sun]].<ref name=kournioitis2018/>

M33-013406.3 is embbed within a prominent ring shaped [[H II region]], large regions of [[Ionization|Ionized]] [[H I region|hydrogen clouds]] with lots of [[star formation]] occurring in them.<ref>{{Cite web |title=H II region {{!}} Astronomy, Star Formation & Nebulae {{!}} Britannica |url=https://www.britannica.com/science/H-II-region |access-date=2023-11-03 |website=www.britannica.com |language=en}}</ref><ref>{{Cite journal |title=Nebular Spectroscopy: A Guide on H ii Regions and Planetary Nebulae |url=https://iopscience.iop.org/article/10.1088/1538-3873/aa72c3/pdf |doi=10.1088/1538-3873/aa72c3 |date=2017 |last1=Peimbert |first1=Manuel |last2=Peimbert |first2=Antonio |last3=Delgado-Inglada |first3=Gloria |journal=Publications of the Astronomical Society of the Pacific |volume=129 |issue=978 |arxiv=1705.06323 |bibcode=2017PASP..129h2001P }}</ref> It is also near the center of the [[H II region]] its in and possible associated with the [[Nebula|nebula's]] origin.<ref>{{Cite journal |last1=Humphreys |first1=Roberta M. |last2=Weis |first2=Kerstin |last3=Davidson |first3=Kris |last4=Bomans |first4=D. J. |last5=Burggraf |first5=Birgitta |date=2014-07-02 |title=LUMINOUS AND VARIABLE STARS IN M31 AND M33. II. LUMINOUS BLUE VARIABLES, CANDIDATE LBVs, Fe II EMISSION LINE STARS, AND OTHER SUPERGIANTS |journal=The Astrophysical Journal |volume=790 |issue=1 |pages=48 |doi=10.1088/0004-637x/790/1/48 |arxiv=1407.2259 |bibcode=2014ApJ...790...48H |issn=0004-637X|doi-access=free }}</ref>

== Notes ==
{{notelist|refs=

{{efn | name=radius1 | Applying the [[Stefan-Boltzmann Law]] with a nominal [[sun|solar]] [[effective temperature]] of 5,772&nbsp;[[Kelvin|K]]: 
:<math>\sqrt{(5,772/30,000)^4 * 4,680,000} = 80\ R_\odot</math>
}}

{{efn | name=radius2 | Applying the [[Stefan-Boltzmann Law]] with a nominal [[sun|solar]] [[effective temperature]] of 5,772&nbsp;[[Kelvin|K]]: 
:<math>\sqrt{(5,772/10,000)^4 * 10^{5.6}} = 210.2\ R_\odot</math>
}}

}}

== References ==
{{reflist}}

{{Stars of Triangulum}}


{{supergiant-star-stub}}

[[Category:O-type supergiants]]
[[Category:Binary stars]]
[[Category:Triangulum]]
[[Category:Triangulum Galaxy]]
[[Category:Luminous blue variables]]