Blue supergiant

Short description: Hot, luminous star with a spectral type of A9 or earlier

110%">Hertzsprung–Russell diagram

120%">Spectral type

100%">Brown dwarfs

100%">White dwarfs

100%">Red dwarfs

100%">Subdwarfs

100%">Main sequence
("dwarfs")

100%">Subgiants

100%">Giants

100%">Bright giants

100%">Supergiants

100%">Hypergiants

100%">absolute
magni-
tude
(MV)

A blue supergiant (BSG) is a hot, luminous star, often referred to as an OB supergiant. They are usually considered to be those with luminosity class I and spectral class B9 or earlier,[1] although sometimes A-class supergiants are also deemed blue supergiants.[2][3][4]

Blue supergiants are found towards the top left of the Hertzsprung–Russell diagram, above and to the right of the main sequence. By analogy to the red giant branch for low-mass stars, this region is also called the blue giant branch.[2] They are larger than the Sun but smaller than a red supergiant, with surface temperatures of 10,000–50,000 K and luminosities from about 10,000 to a million times that of the Sun. They are most often an evolutionary phase between high-mass, hydrogen-fusing main-sequence stars and helium-fusing red supergiants,[4][5][6] although new research suggests they could be the result of stellar mergers.[7][8]

The majority of supergiants are also blue (B-type) supergiants; blue supergiants from classes O9.5 to B2 are even more common than their main sequence counterparts.[9] More post-main-sequence blue supergiants are observed than what is expected from theoretical models, which expect blue supergiants to be short-lived. This results in the blue supergiant problem, although unusual stellar interiors (such as hotter blue supergiants having oversized hydrogen-fusing cores and cooler ones having undersized helium-fusing cores) may explain this.[10]

## Contents

* 1 Formation
* 2 Properties
* 3 Examples
* 4 References

## Formation

Rigel and the IC 2118 nebula which it illuminates.

It was once believed that blue supergiants originated from a "feeding" with the interstellar medium when stars passed through interstellar dust clouds,[11][8] although the current consensus is that blue supergiants are evolved high-mass stars, a natural consequence of stellar evolution, larger and more luminous than main-sequence stars. O-type and early B-type stars with initial masses around 10–300 M☉ evolve away from the main sequence in just a few million years as their hydrogen is consumed and heavy elements (with atomic numbers of 26 (Fe) and less) start to appear near the surface of the star. These stars usually become blue supergiants, although it is possible that some of them (particularly the more massive ones) evolve directly to Wolf–Rayet stars.[12] Expansion into the supergiant stage occurs when hydrogen in the core of the star is depleted and hydrogen shell burning starts, but it may also be caused as heavy elements are dredged up to the surface by convection and mass loss due to radiation pressure increases.[13]

Blue supergiants are newly evolved from the main sequence, have extremely high luminosities, high mass loss rates, and are generally unstable. Many of them become luminous blue variables (LBVs) with episodes of extreme mass loss. Lower mass blue supergiants continue to expand until they become red supergiants. In the process they must spend some time as yellow supergiants or yellow hypergiants, but this expansion occurs in just a few thousand years and so these stars are rare. Higher mass red supergiants blow away their outer atmospheres and evolve back to blue supergiants, and possibly onwards to Wolf–Rayet stars.[14][15] Depending on the exact mass and composition of a red supergiant, it can execute a number of blue loops before either exploding as a type II supernova or finally dumping enough of its outer layers to become a blue supergiant again, less luminous than the first time but more unstable.[16] If such a star can pass through the yellow evolutionary void it is expected that it becomes one of the lower luminosity LBVs.[17]

The most massive blue supergiants are too luminous to retain an extensive atmosphere and they never expand into a red supergiant. The dividing line is approximately 40 M☉, although the coolest and largest red supergiants develop from stars with initial masses of 15–25 M☉. It is not clear whether more massive blue supergiants can lose enough mass to evolve safely into old age as a Wolf Rayet star and finally a white dwarf, or they reach the Wolf Rayet stage and explode as supernovae, or they explode as supernovae while blue supergiants.[12]

Supernova progenitors are most commonly red supergiants and it was believed that only red supergiants could explode as supernovae. SN 1987A, however, forced astronomers to re-examine this theory, as its progenitor, Sanduleak -69° 202, was a B3 blue supergiant.[18] Now it is known from observation that almost any class of evolved high-mass star, including blue and yellow supergiants, can explode as a supernova although theory still struggles to explain how in detail.[19] While most supernovae are of the relatively homogeneous type II-P and are produced by red supergiants, blue supergiants are observed to produce supernovae with a wide range of luminosities, durations, and spectral types, sometimes sub-luminous like SN 1987A, sometimes super-luminous such as many type IIn supernovae.[20][21][22]

## Properties

Spectrum of a B2 star.

Because of their extreme masses they have relatively short lifespans and are mainly observed in young cosmic structures such as open clusters, the arms of spiral galaxies, and in irregular galaxies. They are rarely observed in spiral galaxy cores, elliptical galaxies, or globular clusters, most of which are believed to be composed of older stars, although the core of the Milky Way has recently been found to be home to several massive open clusters and associated young hot stars.[23]

Many blue supergiant stars are Alpha Cygni variables.[24]

While the stellar wind from a red supergiant is dense and slow, the wind from a blue supergiant is fast but sparse. When a red supergiant becomes a blue supergiant, the faster wind it produces impacts the already emitted slow wind and causes the outflowing material to condense into a thin shell. In some cases, several concentric faint shells can be seen from successive episodes of mass loss, either previous blue loops from the red supergiant stage, or eruptions such as LBV outbursts.[25]

## Examples

* Rigel (β Orionis), a blue (B-type) supergiant, believed to be evolving to the red supergiant phase[26]
* Deneb (Alpha Cygni), a blue-white (A-type) supergiant,[27] believed to be evolving to the red supergiant phase[28]
* Mu Sagittarii, a multiple star system containing a B-type blue supergiant
* Alnitak, an O-type blue supergiant
* Eta Canis Majoris, a blue supergiant of spectral type B5Ia
* UW Canis Majoris (UW CMa), two blue (O-type) supergiants in a binary system
* Zeta Puppis (Naos), a blue (O-type) supergiant, spectral type O4I(n)fp
* Alnilam (Epsilon Orionis) B-type supergiant, spectral type B0Ia, central star of Orion's Belt
* Saiph (Kappa Orionis) B-type supergiant, spectral type B0.5Ia
* Chi2 Orionis B-type supergiant, spectral type B2Ia
* 5 Persei, B-type supergiant, spectral type B5Ia
* 10 Persei, B-type supergiant, spectral type B2Ia
* Omicron² Canis Majoris, B-type supergiant, spectral type B3Ia
* Lambda Cephei, B-type supergiant, spectral type O6.5I(n)fp
* Mu Sagittarii, B-type supergiant, spectral type B8Iab(e)
* 4 Lacertae, B-type supergiant, spectral type B9Iab, believed to be in a blue loop[2]
* Nu Cephei, A-type supergiant, spectral type A2Ia[2]
* Alpha Camelopardalis, O-type supergiant, spectral type O9Ia
* Sigma Cygni, B-type supergiant, spectral type B9Iab

## References

1. ↑ Massey, P.; Puls, J.; Pauldrach, A. W. A.; Bresolin, F.; Kudritzki, R. P.; Simon, T. (2005). "The Physical Properties and Effective Temperature Scale of O-Type Stars as a Function of Metallicity. II. Analysis of 20 More Magellanic Cloud Stars and Results from the Complete Sample". The Astrophysical Journal 627 (1): 477–519. doi:10.1086/430417. Bibcode: 2005ApJ...627..477M.
2. ↑ 2.0 2.1 2.2 2.3 Yüce, Kutluay (2005-01-01). "Spectral Analysis of 4 Lacertae and ν Cephei". Baltic Astronomy 14: 51–82. ISSN 1021-6766. Bibcode: 2005BaltA..14...51Y. https://ui.adsabs.harvard.edu/abs/2005BaltA..14...51Y.
3. ↑ Burgos, A. de; Simon-Díaz, S.; Lennon, D. J.; Dorda, R.; Negueruela, I.; Urbaneja, M. A.; Patrick, L. R.; Herrero, A. (2020-11-01). "High-resolution spectroscopic study of massive blue and red supergiants in Perseus OB1 - I. Definition of the sample, membership, and kinematics" (in en). Astronomy & Astrophysics 643: A116. doi:10.1051/0004-6361/202039019. ISSN 0004-6361. Bibcode: 2020A&A...643A.116D. https://www.aanda.org/articles/aa/abs/2020/11/aa39019-20/aa39019-20.html.
4. ↑ 4.0 4.1 Wagle, Gururaj A.; Ray, Alak; Raghu, Adarsh (May 2020). "Type IIP Supernova Progenitors. III. Blue to Red Supergiant Ratio in Low-metallicity Models with Convective Overshoot" (in en). The Astrophysical Journal 894 (2): 118. doi:10.3847/1538-4357/ab8bd5. ISSN 0004-637X. Bibcode: 2020ApJ...894..118W.
5. ↑ Gordon, Michael S.; Humphreys, Roberta M. (December 2019). "Red Supergiants, Yellow Hypergiants, and Post-RSG Evolution" (in en). Galaxies 7 (4): 92. doi:10.3390/galaxies7040092. ISSN 2075-4434. Bibcode: 2019Galax...7...92G.
6. ↑ Vamvatira-Nakou, C.; Hutsemékers, D.; Royer, P.; Nazé, Y.; Magain, P.; Exter, K.; Waelkens, C.; Groenewegen, M. a. T. (2013-09-01). "Herschel imaging and spectroscopy of the nebula around the luminous blue variable star WRAY 15-751" (in en). Astronomy & Astrophysics 557: A20. doi:10.1051/0004-6361/201321853. ISSN 0004-6361. Bibcode: 2013A&A...557A..20V. https://www.aanda.org/articles/aa/abs/2013/09/aa21853-13/aa21853-13.html.
7. ↑ Menon, Athira; Ercolino, Andrea; Urbaneja, Miguel A.; Lennon, Daniel J.; Herrero, Artemio; Hirai, Ryosuke; Langer, Norbert; Schootemeijer, Abel et al. (March 2024). "Evidence for Evolved Stellar Binary Mergers in Observed B-type Blue Supergiants" (in en). The Astrophysical Journal Letters 963 (2): L42. doi:10.3847/2041-8213/ad2074. ISSN 2041-8205. Bibcode: 2024ApJ...963L..42M.
8. ↑ 8.0 8.1 Koberlein, Brian (2024-03-26). "Merging Stars Can Lead to Blue Supergiants" (in en-US). https://www.universetoday.com/166306/merging-stars-can-lead-to-blue-supergiants/.
9. ↑ Sowell, J. R.; Trippe, M.; Caballero-Nieves, S. M.; Houk, N. (2007-07-18). "H-R Diagrams Based on the HD Stars in the Michigan Spectral Catalogue and the Hipparcos Catalog" (in en). The Astronomical Journal 134 (3): 1089. doi:10.1086/520060. ISSN 1538-3881. Bibcode: 2007AJ....134.1089S. https://iopscience.iop.org/article/10.1086/520060/meta.
10. ↑ Bellinger, Earl Patrick; de Mink, Selma E.; van Rossem, Walter E.; Justham, Stephen (2024). "The Potential of Asteroseismology to Resolve the Blue Supergiant Problem". The Astrophysical Journal 967 (2): L39. doi:10.3847/2041-8213/ad4990. Bibcode: 2024ApJ...967L..39B.
11. ↑ Galaxy v23n06 (1965 08). http://archive.org/details/Galaxy_v23n06_1965-08.
12. ↑ 12.0 12.1 Georges Meynet; Cyril Georgy; Raphael Hirschi; Andre Maeder; Phil Massey; Norbert Przybilla; Fernanda Nieva (2011). "Red Supergiants, Luminous Blue Variables and Wolf-Rayet stars: The single massive star perspective". Bulletin de la Société Royale des Sciences de Liège 80 (39): 266–278. Bibcode: 2011BSRSL..80..266M.
13. ↑ Eggenberger, P.; Meynet, G.; Maeder, A. (2009). "Modelling massive stars with mass loss". Communications in Asteroseismology 158: 87. Bibcode: 2009CoAst.158...87E.
14. ↑ Origlia, L.; Goldader, J. D.; Leitherer, C.; Schaerer, D.; Oliva, E. (1999). "Evolutionary Synthesis Modeling of Red Supergiant Features in the Near-Infrared". The Astrophysical Journal 514 (1): 96–108. doi:10.1086/306937. Bibcode: 1999ApJ...514...96O.
15. ↑ Neugent; Philip Massey; Brian Skiff; Georges Meynet (2012). "Yellow and Red Supergiants in the Large Magellanic Cloud". The Astrophysical Journal 749 (2): 177. doi:10.1088/0004-637X/749/2/177. Bibcode: 2012ApJ...749..177N.
16. ↑ Maeder, A.; Meynet, G. (2001). "Stellar evolution with rotation. VII". Astronomy and Astrophysics 373 (2): 555–571. doi:10.1051/0004-6361:20010596. Bibcode: 2001A&A...373..555M.
17. ↑ Stothers, R. B.; Chin, C. W. (2001). "Yellow Hypergiants as Dynamically Unstable Post–Red Supergiant Stars". The Astrophysical Journal 560 (2): 934. doi:10.1086/322438. Bibcode: 2001ApJ...560..934S.
18. ↑ Smith, N.; Immler, S.; Weiler, K. (2007). "Galactic Twins of the Nebula Around SN 1987A: Hints that LBVS may be supernova progenitors". AIP Conference Proceedings 937: 163–170. doi:10.1063/1.3682897.
19. ↑ Gal-Yam, A.; Leonard, D. C. (2009). "A Massive Hypergiant Star as the Progenitor of the Supernova SN 2005gl". Nature 458 (7240): 865–867. doi:10.1038/nature07934. PMID 19305392. Bibcode: 2009Natur.458..865G. http://hubblesite.org/pubinfo/pdf/2009/13/pdf.pdf. Retrieved 2015-08-28.
20. ↑ Mauerhan; Nathan Smith; Alexei Filippenko; Kyle Blanchard; Peter Blanchard; Casper; Bradley Cenko; Clubb et al. (2012). "The Unprecedented Third Outburst of SN 2009ip: A Luminous Blue Variable Becomes a Supernova". American Astronomical Society Meeting Abstracts #221 221: 233.03. doi:10.1093/mnras/stt009. Bibcode: 2013AAS...22123303M.
21. ↑ Kleiser, I.; Poznanski, D.; Kasen, D. et al. (2011). "The Peculiar Type II Supernova 2000cb". Bulletin of the American Astronomical Society 43: 33726. Bibcode: 2011AAS...21733726K.
22. ↑ Georgy, C. (2012). "Yellow supergiants as supernova progenitors: An indication of strong mass loss for red supergiants?". Astronomy & Astrophysics 538: L8–L2. doi:10.1051/0004-6361/201118372. Bibcode: 2012A&A...538L...8G.
23. ↑ Figer, D. F.; Kim, S. S.; Morris, M.; Serabyn, E.; Rich, R. M.; McLean, I. S. (1999). "Hubble Space Telescope/NICMOS Observations of Massive Stellar Clusters near the Galactic Center". The Astrophysical Journal 525 (2): 750. doi:10.1086/307937. Bibcode: 1999ApJ...525..750F. https://cds.cern.ch/record/390820/files/9906299.pdf.
24. ↑ Saio, H.; Georgy, C.; Meynet, G. (2013). "Strange-Mode Instability for Micro-Variations in Luminous Blue Variables". Progress in Physics of the Sun and Stars: A New Era in Helio- and Asteroseismology. Proceedings of a Fujihara Seminar held 25–29 November. Astronomical Society of the Pacific Conference Series. 479. pp. 47. Bibcode: 2013ASPC..479...47S.
25. ↑ Chiţǎ, S. M.; Langer, N.; Van Marle, A. J.; García-Segura, G.; Heger, A. (2008). "Multiple ring nebulae around blue supergiants". Astronomy and Astrophysics 488 (2): L37. doi:10.1051/0004-6361:200810087. Bibcode: 2008A&A...488L..37C.
26. ↑ Przybilla, N.; Butler, K.; Becker, S. R.; Kudritzki, R. P. (2005-09-22). "Quantitative spectroscopy of BA-type supergiants" (in en). Astronomy & Astrophysics 445 (3): 1099–1126. doi:10.1051/0004-6361:20053832.
27. ↑ "Deneb | Blue Supergiant, Cygnus Constellation & Alpha Cygni | Britannica" (in en). https://www.britannica.com/place/Deneb.
28. ↑ Schiller, Florian; Przybilla, Norbert (2007-12-01). "Quantitative spectroscopy of Deneb" (in en). Astronomy & Astrophysics 479 (3): 849–858. doi:10.1051/0004-6361:20078590.

* v
* t
* e

Stars

Formation|

* Accretion
* Molecular cloud
* Bok globule
* Young stellar object
* Protostar
* Pre-main-sequence
* Herbig Ae/Be
* T Tauri
* FU Orionis
* Herbig–Haro object
* Hayashi track
* Henyey track

Evolution|

* Main sequence
* Red-giant branch
* Horizontal branch
* Red clump
* Asymptotic giant branch
* Blue loop
* Protoplanetary nebula
* Planetary nebula
* PG1159
* Dredge-up
* Instability strip
* Luminous blue variable
* Blue straggler
* Stellar population
* Supernova
* Superluminous supernova / Hypernova

Spectral
classification|

* Early
* Late
* Main sequence
* O
* B
* A
* F
* G
* K
* M
* Brown dwarf
* WR
* OB
* Subdwarf
* O
* B
* Subgiant
* Giant
* Blue
* Red
* Yellow
* Bright giant
* Supergiant
* Blue
* Red
* Yellow
* Hypergiant
* Yellow
* Carbon
* S
* CN
* CH
* White dwarf
* Chemically peculiar
* Am
* Ap/Bp
* HgMn
* Helium-weak
* Barium
* Extreme helium
* Lambda Boötis
* Lead
* Technetium
* Be
* Shell
* B[e]

Remnants|

* White dwarf
* Helium planet
* Black dwarf
* Neutron
* Radio-quiet
* Pulsar
* Binary
* X-ray
* Magnetar
* Stellar black hole
* X-ray binary
* Burster

Hypothetical|

* Blue dwarf
* Green
* Black dwarf
* Exotic
* Boson
* Electroweak
* Strange
* Preon
* Planck
* Dark
* Dark-energy
* Quark
* Q
* Black
* Gravastar
* Frozen
* Quasi-star
* Thorne–Żytkow object
* Iron
* Blitzar

Stellar
nucleosynthesis|

* Deuterium burning
* Lithium burning
* Proton–proton chain
* CNO cycle
* Helium flash
* Triple-alpha process
* Alpha process
* Carbon burning
* Neon burning
* Oxygen burning
* Silicon burning
* S-process
* R-process
* Fusor
* Nova
* Symbiotic
* Remnant
* Luminous red nova

Structure|

* Core
* Convection zone
* Microturbulence
* Oscillations
* Radiation zone
* Atmosphere
* Photosphere
* Starspot
* Chromosphere
* Corona
* Stellar wind
* Bubble
* Bipolar outflow
* Accretion disk
* Asteroseismology
* Helioseismology
* Eddington luminosity
* Kelvin–Helmholtz mechanism

Properties|

* Designation
* Dynamics
* Effective temperature
* Luminosity
* Kinematics
* Magnetic field
* Absolute magnitude
* Mass
* Metallicity
* Rotation
* Starlight
* Variable
* Photometric system
* Color index
* Hertzsprung–Russell diagram
* Color–color diagram

Star systems|

* Binary
* Contact
* Common envelope
* Eclipsing
* Symbiotic
* Multiple
* Cluster
* Open
* Globular
* Super
* Planetary system

Earth-centric
observations|

* Sun
* Solar System
* Sunlight
* Pole star
* Circumpolar
* Constellation
* Asterism
* Magnitude
* Apparent
* Extinction
* Photographic
* Radial velocity
* Proper motion
* Parallax
* Photometric-standard

Lists|

* Proper names
* Arabic
* Chinese
* Extremes
* Most massive
* Highest temperature
* Largest volume
* Smallest volume
* Brightest
* Historical
* Most luminous
* Nearest
* Nearest bright
* With exoplanets
* Brown dwarfs
* White dwarfs
* Milky Way novae
* Supernovae
* Candidates
* Remnants
* Planetary nebulae
* Timeline of stellar astronomy

Related articles|

* Substellar object
* Brown dwarf
* Sub-brown dwarf
* Planet
* Galactic year
* Galaxy
* Guest
* Gravity
* Intergalactic
* Starfield
* Tidal disruption event

'Category:Stars * '

* v
* t
* e

Supernovae

Classes|

* Type Ia
* Type Ib and Ic
* Type II (IIP, IIL, IIn, and IIb)
* Hypernova
* Superluminous
* Pair-instability

Physics of|

* Calcium-rich
* Carbon detonation
* Foe
* Near-Earth
* Phillips relationship
* Nucleosynthesis
* P-process
* R-process
* Neutrinos

Related|

* Imposter
* pulsational pair-instability
* Failed
* Gamma-ray burst
* Kilonova
* Luminous red nova
* Nova
* Pulsar kick
* Quark-nova
* Symbiotic nova

Progenitors|

* Hypergiant
* yellow
* Luminous blue variable
* Supergiant
* blue
* red
* yellow
* White dwarf
* related links
* Wolf–Rayet star

Remnants|

* Supernova remnant
* Pulsar wind nebula
* Neutron star
* pulsar
* magnetar
* related links
* Stellar black hole
* related links
* Compact star
* quark star
* exotic star
* Zombie star
* Local Bubble
* Superbubble
* Orion–Eridanus

Discovery|

* Guest star
* History of supernova observation
* Timeline of white dwarfs, neutron stars, and supernovae

Lists|

* Candidates
* Notable
* Massive stars
* Most distant
* Remnants
* In fiction

Notable|

* Barnard's Loop
* Cassiopeia A
* Crab
* Crab Nebula
* iPTF14hls
* Tycho's
* Kepler's
* SN 1987A
* SN 185
* SN 1006
* SN 2003fg
* Remnant G1.9+0.3
* SN 2007bi
* SN 2011fe
* SN 2014J
* SN Refsdal
* Vela Remnant

Research|

* ASAS-SN
* Calán/Tololo Survey
* High-Z Supernova Search Team
* Katzman Automatic Imaging Telescope
* Monte Agliale Supernovae and Asteroid Survey
* Nearby Supernova Factory
* Sloan Supernova Survey
* Supernova/Acceleration Probe
* Supernova Cosmology Project
* SuperNova Early Warning System
* Supernova Legacy Survey
* Texas Supernova Search

* Book:Supernovae
* Category:Supernovae
* Commons:Supernovae

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/Blue supergiant. Read more

|

Retrieved from "https://handwiki.org/wiki/index.php?title=Astronomy:Blue_supergiant&oldid=4342080"
*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template