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Mu Cephei

May 06, 2023

Not to be confused with MY Cephei.

Mu Cephei (Latinized from μ Cephei, abbreviated Mu Cep or μ Cep), also known as Herschel's Garnet Star, Erakis, or HD 206936, is a red supergiant or hypergiant[4] star in the constellation Cepheus. It appears garnet red and is located at the edge of the IC 1396 nebula. Since 1943, the spectrum of this star has served as a spectral standard by which other stars are classified.

μ Cephei
Location of μ Cep (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cepheus
Right ascension 21h 43m 30.4609s[1]
Declination +58° 46′ 48.166″[1]
Apparent magnitude (V) +4.08[2] (3.43 - 5.1[3])
Characteristics
Evolutionary stage Red supergiant or hypergiant[4]
Spectral type M2-Ia[5] (M2e Ia[6])
U−B color index +2.42[2]
B−V color index +2.35[2]
Variable type SRc[3]
Astrometry
Radial velocity (Rv)+20.63[7] km/s
Proper motion (μ) RA: 2.740±0.884[8] mas/yr
Dec.: −5.941±0.922[8] mas/yr
Parallax (π)0.55 ± 0.20 mas[9]
Distance3,060 ly
(940+140
−40[10] pc)
Absolute magnitude (MV)–7.63[11]
Details
Mass19.2±0.1[12] M☉
Radius972±228[13] (1,259[14] – 1,420[11])[15] R☉
Luminosity269,000+111,000
−40,000[10] (135,000[13] – 340,000[11]) L☉
Surface gravity (log g)–0.36[14] – –0.5[11] cgs
Temperature3,551±136[13] (3,750[14] – 3,700[11])[15] K
Age10.0±0.1[12] Myr
Other designations
Erakis, Herschel's Garnet Star, μ Cep, HD 206936, HR 8316, BD+58°2316, HIP 107259, SAO 33693
Database references
SIMBADdata

Mu Cephei is visually nearly 100,000 times brighter than the Sun, with an absolute visual magnitude of −7.6. It is also one of the largest known stars with a radius around or over 1,000 times that of the sun (R☉), and were it placed in the Sun's position it would engulf the orbit of Mars and Jupiter.

History

 
1785 portrait of William Herschel
Zooming to the μ Cep (Garnet star) in the constellation Cepheus.

The deep red color of Mu Cephei was noted by William Herschel, who described it as "a very fine deep garnet colour, such as the periodical star ο Ceti".[16] It is thus commonly known as Herschel's "Garnet Star".[17] Mu Cephei was called Garnet sidus by Giuseppe Piazzi in his catalogue.[18][19] An alternative name, Erakis, used in Antonín Bečvář's star catalogue, is probably due to confusion with Mu Draconis, which was previously called al-Rāqis [arˈraːqis] in Arabic.[20]

In 1848, English astronomer John Russell Hind discovered that Mu Cephei was variable. This variability was quickly confirmed by German astronomer Friedrich Wilhelm Argelander. Almost continual records of the star's variability have been maintained since 1881.[21]

The angular diameter of μ Cephei has been measured interferometrically. One of the most recent measurements gives a diameter of 18.672±0.435 mas at 800 μm, modelled as a limb-darkened disk 20.584±0.480 mas across.[22] μ Cephei was used as one of the original "dagger stars", those with well-defined spectra that could be used for the classification of other stars, for MK spectral classifications. In 1943 it was the standard star for M2  Ia, updated in 1980 to be the standard star for the new type M2- Ia.[5][23]

Distance

 
Mu Cephei (circled) as can be seen in binoculars. The bright star on the right is Alpha Cephei (Alderamin).
 
Image of Mu Cephei

The distance to Mu Cephei is not very well known. The Hipparcos satellite was used to measure a parallax of 0.55±0.20 mas, which corresponds to an estimated distance of 1,800 parsecs. However, this value is close to the margin of error. A determination of the distance based upon a size comparison with Betelgeuse gives an estimate of 390±140 parsecs.[24]

Calculation of the distance from the measured angular diameter, surface brightness, and calculated luminosity leads to 641 pc. Averaging the distances of nearby luminous stars with similar reddening and reliable Gaia Data Release 2 parallaxes gives a distance of 940 pc.[10]

Surroundings

Mu Cephei is surrounded by a shell extending out to a distance at least equal to 0.33 times the star's radius with a temperature of 2,055±25 K. This outer shell appears to contain molecular gases such as CO, H2O, and SiO.[24] Infrared observations suggest the presence of a wide ring of dust and water with an inner radius about twice that of the star itself, extending to about four times the radius of the star.[25][26]

The star is surrounded by a spherical shell of ejected material that extends outward to an angular distance of 6″ with an expansion velocity of 10 km s−1. This indicates an age of about 2,000–3,000 years for the shell. Closer to the star, this material shows a pronounced asymmetry, which may be shaped as a torus.

Variability

 
A visual band light curve for Mu Cephei, adapted from Brelstaff et al. (1997)[21]

Mu Cephei is a variable star and the prototype of the obsolete class of the Mu Cephei variables. It is now considered to be a semiregular variable of type SRc. Its apparent brightness varies erratically between magnitude 3.4 and 5.1. Many different periods have been reported, but they are consistently near 860 days or 4,400 days.[27]

Properties

 
(July 2008, outdated). Relative sizes of the planets in the Solar System and several well-known stars, including Mu Cephei.
1. Mercury < Mars < Venus < Earth
2. Earth < Neptune < Uranus < Saturn < Jupiter
3. Jupiter < Wolf 359 < Sun < Sirius
4. Sirius < Pollux < Arcturus < Aldebaran
5. Aldebaran < Rigel < Antares < Betelgeuse
6. Betelgeuse < Mu Cephei < VV Cephei A < VY Canis Majoris.
 
Mu Cephei compared to the Sun. The orbits of Jupiter, Mars, Earth, Venus, and Mercury are visible in full-size.

A very luminous red supergiant, Mu Cephei is among the largest stars visible to the naked eye, and one of the largest known cool supergiants. It is a runaway star with a peculiar velocity of 80.7±17.7 km/s,[12] and has been described as a hypergiant.[4]

The bolometric luminosity, summed over all wavelengths, is calculated from integrating the spectral energy distribution (SED) to be 269,000 L☉, making μ Cephei one of the most luminous red supergiants in the Milky Way.[10] Its effective temperature of 3,750 K, determined from colour index relations, implies a radius of 1,259 R☉.[14] Other recent publications give similar effective temperatures. Calculation of the luminosity from a visual and infrared colour relation give 340,000 L☉ and a corresponding radius of 1,420 R☉.[11] An estimate made based on its angular diameter and an assumed distance of 2,400 light years gives it a radius of 1,650 R☉.[28]

A 2019 paper measurement based on the 641+148
−144 pc distance gives the star a lower luminosity below 140,000 L☉ and a correspondingly lower radius of 972±228 R☉, and as well as a lower temperature of 3,551±136 K. These parameters are all consistent with those estimated for Betelgeuse.[13]

The initial mass of Mu Cephei has been estimated from its position relative to theoretical stellar evolutionary tracks to be between 15 M☉ and 25 M☉.[13][14] The star currently has a mass loss rate of (4.9±1.0)×10−7 M☉ per year.[13]

Supernova

Mu Cephei is nearing death. It has begun to fuse helium into carbon, whereas a main sequence star fuses hydrogen into helium. When a supergiant star has converted elements in its core to iron, the core collapses to produce a supernova and the star is destroyed, leaving behind a vast gaseous cloud and a small, dense remnant. For a star as massive as Mu Cephei the remnant is likely to be a black hole. The most massive red supergiants will evolve back to blue supergiants, Luminous blue variables, or Wolf-Rayet stars before their cores collapse, and Mu Cephei appears to be massive enough for this to happen. A post-red supergiant will produce a type IIn or type II-b supernova, while a Wolf Rayet star will produce a type Ib or Ic supernova.[29]

Components

There are several faint stars within two arc-minutes of Mu Cephei, and listed in multiple star catalogues.

NAME Right ascension Declination Apparent magnitude (V) Database references
μ Cep B (CCDM J21435+5847B) 21h 43m 27.8s +58° 46′ 45″ 12.3
μ Cep C (CCDM J21435+5847C) 21h 43m 25.6s +58° 47′ 08″ 12.7 Simbad

See also

References

  1. ^ a b Perryman, M. A. C.; et al. (April 1997). "The HIPPARCOS Catalogue". Astronomy and Astrophysics. 323: L49–L52. Bibcode:1997A&A...323L..49P.
  2. ^ a b c Nicolet, B. (October 1978). "Catalogue of homogeneous data in the UBV photoelectric photometric system". Astronomy & Astrophysics Supplement Series. 34: 1–49. Bibcode:1978A&AS...34....1N.
  3. ^ a b Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: B/gcvs. Bibcode:2009yCat....102025S.
  4. ^ a b c Shenoy, Dinesh; Humphreys, Roberta M; Terry Jay Jones; Marengo, Massimo; Gehrz, Robert D; Andrew Helton, L; Hoffmann, William F; Skemer, Andrew J; Hinz, Philip M (2015). "Searching for Cool Dust in the Mid-to-Far Infrared: The Mass Loss Histories of the Hypergiants μ Cep, VY CMa, IRC+10420, and ρ Cas". The Astronomical Journal. 151 (3): 51. arXiv:1512.01529. Bibcode:2016AJ....151...51S. doi:10.3847/0004-6256/151/3/51. S2CID 119281306.
  5. ^ a b Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series. 71: 245. Bibcode:1989ApJS...71..245K. doi:10.1086/191373.
  6. ^ Shenavrin, V. I.; Taranova, O. G.; Nadzhip, A. E. (2011). "Search for and study of hot circumstellar dust envelopes". Astronomy Reports. 55 (1): 31. Bibcode:2011ARep...55...31S. doi:10.1134/S1063772911010070. S2CID 122700080.
  7. ^ Famaey, B.; et al. (2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters". Astronomy and Astrophysics. 430 (1): 165–186. arXiv:astro-ph/0409579. Bibcode:2005A&A...430..165F. doi:10.1051/0004-6361:20041272. S2CID 17804304.
  8. ^ a b Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  9. ^ Hipparcos, the New Reduction (van Leeuwen, 2007)
  10. ^ a b c d Davies, Ben; Beasor, Emma R. (March 2020). "The 'red supergiant problem': the upper luminosity boundary of Type II supernova progenitors". MNRAS. 493 (1): 468–476. arXiv:2001.06020. Bibcode:2020MNRAS.493..468D. doi:10.1093/mnras/staa174. S2CID 210714093.
  11. ^ a b c d e f Table 4 in Emily M. Levesque; Philip Massey; K. A. G. Olsen; Bertrand Plez; Eric Josselin; Andre Maeder & Georges Meynet (2005). "The Effective Temperature Scale of Galactic Red Supergiants: Cool, but Not As Cool As We Thought". The Astrophysical Journal. 628 (2): 973–985. arXiv:astro-ph/0504337. Bibcode:2005ApJ...628..973L. doi:10.1086/430901. S2CID 15109583.
  12. ^ a b c Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
  13. ^ a b c d e f Montargès, M.; Homan, W.; Keller, D.; Clementel, N.; Shetye, S.; Decin, L.; Harper, G. M.; Royer, P.; Winters, J. M.; Le Bertre, T.; Richards, A. M. S. (2019). "NOEMA maps the CO J = 2 − 1 environment of the red supergiant μ Cep". Monthly Notices of the Royal Astronomical Society. 485 (2): 2417–2430. arXiv:1903.07129. Bibcode:2019MNRAS.485.2417M. doi:10.1093/mnras/stz397. S2CID 119423161.
  14. ^ a b c d e Josselin, E.; Plez, B. (2007). "Atmospheric dynamics and the mass loss process in red supergiant stars". Astronomy and Astrophysics. 469 (2): 671–680. arXiv:0705.0266. Bibcode:2007A&A...469..671J. doi:10.1051/0004-6361:20066353. S2CID 17789027.
  15. ^ a b Kravchenko, K.; Chiavassa, A.; Van Eck, S.; Jorissen, A.; Merle, T.; Freytag, B.; Plez, B. (2019). "Tomography of cool giant and supergiant star atmospheres". Astronomy & Astrophysics. 632: A28. arXiv:1910.04657. doi:10.1051/0004-6361/201935809. S2CID 204924849.
  16. ^ Herschel, W. (1783). "Stars newly come to be visible". Philosophical Transactions: 257.
  17. ^ Allen, R. H. (1899). Star Names: Their Lore and Meaning. G. E. Stechert. p. 158. editions:CmkItwtawcMC.
  18. ^ Piazzi, G., ed. (1803). Præcipuarum Stellarum Inerrantium Positiones Mediæ Ineunte Seculo XIX: ex Observationibus Habitis in Specula Panormitana ab anno 1792 ad annum 1802. Panormi.
  19. ^ Piazzi, G., ed. (1814). Praecipuarum Stellarum Inerrantium Positiones Mediae Ineunte Saeculo XIX: ex Observationibus Habitis in Specula Panormitana ab anno 1792 ad annum 1813. Panormi. p. 159.
  20. ^ Laffitte, R. (2005). Héritages arabes: Des noms arabes pour les étoiles (2éme revue et corrigée ed.). Paris: Librairie Orientaliste Paul Geunthner / Les Cahiers de l'Orient. p. 156, note 267.
  21. ^ a b Brelstaff, T.; Lloyd, C.; Markham, T.; McAdam, D. (June 1997). "The periods of MU Cephei". Journal of the British Astronomical Association. 107 (3): 135–140. Bibcode:1997JBAA..107..135B.
  22. ^ Mozurkewich, D.; Armstrong, J. T.; Hindsley, R. B.; Quirrenbach, A.; Hummel, C. A.; Hutter, D. J.; Johnston, K. J.; Hajian, A. R.; Elias, Nicholas M.; Buscher, D. F.; Simon, R. S. (2003). "Angular Diameters of Stars from the Mark III Optical Interferometer". The Astronomical Journal. 126 (5): 2502. Bibcode:2003AJ....126.2502M. doi:10.1086/378596. S2CID 67789347.
  23. ^ Garrison, R. F. (December 1993), "Anchor Points for the MK System of Spectral Classification", Bulletin of the American Astronomical Society, 25: 1319, Bibcode:1993AAS...183.1710G
  24. ^ a b Perrin, G.; et al. (2005). "Study of molecular layers in the atmosphere of the supergiant star μ Cep by interferometry in the K band". Astronomy & Astrophysics. 436 (1): 317–324. arXiv:astro-ph/0502415. Bibcode:2005A&A...436..317P. doi:10.1051/0004-6361:20042313. S2CID 13980310.
  25. ^ Tsuji, Takashi (2000). "Water in Emission in the Infrared Space Observatory Spectrum of the Early M Supergiant Star μ Cephei". The Astrophysical Journal Letters. 540 (2): 99–102. arXiv:astro-ph/0008058. Bibcode:2000ApJ...540L..99T. doi:10.1086/312879. S2CID 14881959.
  26. ^ Tsuji, T. (2000). "Water on the Early M Supergiant Stars α Orionis and μ Cephei". The Astrophysical Journal. 538 (2): 801–807. Bibcode:2000ApJ...538..801T. doi:10.1086/309185.
  27. ^ Kiss, L. L.; Szabó, G. M.; Bedding, T. R. (2006). "Variability in red supergiant stars: Pulsations, long secondary periods and convection noise". Monthly Notices of the Royal Astronomical Society. 372 (4): 1721–1734. arXiv:astro-ph/0608438. Bibcode:2006MNRAS.372.1721K. doi:10.1111/j.1365-2966.2006.10973.x. S2CID 5203133.
  28. ^ "Jim Kaler-Garnet star".
  29. ^ Meynet, G.; Chomienne, V.; Ekström, S.; Georgy, C.; Granada, A.; Groh, J.; Maeder, A.; Eggenberger, P.; Levesque, E.; Massey, P. (2015). "Impact of mass-loss on the evolution and pre-supernova properties of red supergiants". Astronomy & Astrophysics. 575 (60): A60. arXiv:1410.8721. Bibcode:2015A&A...575A..60M. doi:10.1051/0004-6361/201424671. S2CID 38736311.

External links

  • "mu. Cep". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 15 December 2013.
  • "GARNET STAR (Mu Cephei)". Jim Kaler: Stars. Retrieved 15 December 2013.
  • "Mu Cephei". AAVSO: Variable Star of the Season Archive. Retrieved 15 December 2013.
  • "IC 1396". Matt Ben Daniel: Starmatt Astrophotography. Retrieved 15 December 2013.
  • "Garnet Star". Jumk.de Webprojects: Big and Giant Stars. Retrieved 15 December 2013.


May 06, 2023
cephei, confused, with, cephei, latinized, from, cephei, abbreviated, also, known, herschel, garnet, star, erakis, 206936, supergiant, hypergiant, star, constellation, cepheus, appears, garnet, located, edge, 1396, nebula, since, 1943, spectrum, this, star, se. Not to be confused with MY Cephei Mu Cephei Latinized from m Cephei abbreviated Mu Cep or m Cep also known as Herschel s Garnet Star Erakis or HD 206936 is a red supergiant or hypergiant 4 star in the constellation Cepheus It appears garnet red and is located at the edge of the IC 1396 nebula Since 1943 the spectrum of this star has served as a spectral standard by which other stars are classified m CepheiLocation of m Cep circled Observation dataEpoch J2000 0 Equinox J2000 0Constellation CepheusRight ascension 21h 43m 30 4609s 1 Declination 58 46 48 166 1 Apparent magnitude V 4 08 2 3 43 5 1 3 CharacteristicsEvolutionary stage Red supergiant or hypergiant 4 Spectral type M2 Ia 5 M2e Ia 6 U B color index 2 42 2 B V color index 2 35 2 Variable type SRc 3 AstrometryRadial velocity Rv 20 63 7 km sProper motion m RA 2 740 0 884 8 mas yr Dec 5 941 0 922 8 mas yrParallax p 0 55 0 20 mas 9 Distance3 060 ly 940 140 40 10 pc Absolute magnitude MV 7 63 11 DetailsMass19 2 0 1 12 M Radius972 228 13 1 259 14 1 420 11 15 R Luminosity269 000 111 000 40 000 10 135 000 13 340 000 11 L Surface gravity log g 0 36 14 0 5 11 cgsTemperature3 551 136 13 3 750 14 3 700 11 15 KAge10 0 0 1 12 MyrOther designationsErakis Herschel s Garnet Star m Cep HD 206936 HR 8316 BD 58 2316 HIP 107259 SAO 33693Database referencesSIMBADdataMu Cephei is visually nearly 100 000 times brighter than the Sun with an absolute visual magnitude of 7 6 It is also one of the largest known stars with a radius around or over 1 000 times that of the sun R and were it placed in the Sun s position it would engulf the orbit of Mars and Jupiter Contents 1 History 2 Distance 3 Surroundings 4 Variability 5 Properties 6 Supernova 7 Components 8 See also 9 References 10 External linksHistory Edit 1785 portrait of William Herschel source source source source source source source source source source source source source source source source Zooming to the m Cep Garnet star in the constellation Cepheus The deep red color of Mu Cephei was noted by William Herschel who described it as a very fine deep garnet colour such as the periodical star o Ceti 16 It is thus commonly known as Herschel s Garnet Star 17 Mu Cephei was called Garnet sidus by Giuseppe Piazzi in his catalogue 18 19 An alternative name Erakis used in Antonin Becvar s star catalogue is probably due to confusion with Mu Draconis which was previously called al Raqis arˈraːqis in Arabic 20 In 1848 English astronomer John Russell Hind discovered that Mu Cephei was variable This variability was quickly confirmed by German astronomer Friedrich Wilhelm Argelander Almost continual records of the star s variability have been maintained since 1881 21 The angular diameter of m Cephei has been measured interferometrically One of the most recent measurements gives a diameter of 18 672 0 435 mas at 800 mm modelled as a limb darkened disk 20 584 0 480 mas across 22 m Cephei was used as one of the original dagger stars those with well defined spectra that could be used for the classification of other stars for MK spectral classifications In 1943 it was the standard star for M2 Ia updated in 1980 to be the standard star for the new type M2 Ia 5 23 Distance Edit Mu Cephei circled as can be seen in binoculars The bright star on the right is Alpha Cephei Alderamin Image of Mu Cephei The distance to Mu Cephei is not very well known The Hipparcos satellite was used to measure a parallax of 0 55 0 20 mas which corresponds to an estimated distance of 1 800 parsecs However this value is close to the margin of error A determination of the distance based upon a size comparison with Betelgeuse gives an estimate of 390 140 parsecs 24 Calculation of the distance from the measured angular diameter surface brightness and calculated luminosity leads to 641 pc Averaging the distances of nearby luminous stars with similar reddening and reliable Gaia Data Release 2 parallaxes gives a distance of 940 pc 10 Surroundings EditMu Cephei is surrounded by a shell extending out to a distance at least equal to 0 33 times the star s radius with a temperature of 2 055 25 K This outer shell appears to contain molecular gases such as CO H2O and SiO 24 Infrared observations suggest the presence of a wide ring of dust and water with an inner radius about twice that of the star itself extending to about four times the radius of the star 25 26 The star is surrounded by a spherical shell of ejected material that extends outward to an angular distance of 6 with an expansion velocity of 10 km s 1 This indicates an age of about 2 000 3 000 years for the shell Closer to the star this material shows a pronounced asymmetry which may be shaped as a torus Variability Edit A visual band light curve for Mu Cephei adapted from Brelstaff et al 1997 21 Mu Cephei is a variable star and the prototype of the obsolete class of the Mu Cephei variables It is now considered to be a semiregular variable of type SRc Its apparent brightness varies erratically between magnitude 3 4 and 5 1 Many different periods have been reported but they are consistently near 860 days or 4 400 days 27 Properties Edit July 2008 outdated Relative sizes of the planets in the Solar System and several well known stars including Mu Cephei 1 Mercury lt Mars lt Venus lt Earth 2 Earth lt Neptune lt Uranus lt Saturn lt Jupiter 3 Jupiter lt Wolf 359 lt Sun lt Sirius 4 Sirius lt Pollux lt Arcturus lt Aldebaran 5 Aldebaran lt Rigel lt Antares lt Betelgeuse 6 Betelgeuse lt Mu Cephei lt VV Cephei A lt VY Canis Majoris Mu Cephei compared to the Sun The orbits of Jupiter Mars Earth Venus and Mercury are visible in full size A very luminous red supergiant Mu Cephei is among the largest stars visible to the naked eye and one of the largest known cool supergiants It is a runaway star with a peculiar velocity of 80 7 17 7 km s 12 and has been described as a hypergiant 4 The bolometric luminosity summed over all wavelengths is calculated from integrating the spectral energy distribution SED to be 269 000 L making m Cephei one of the most luminous red supergiants in the Milky Way 10 Its effective temperature of 3 750 K determined from colour index relations implies a radius of 1 259 R 14 Other recent publications give similar effective temperatures Calculation of the luminosity from a visual and infrared colour relation give 340 000 L and a corresponding radius of 1 420 R 11 An estimate made based on its angular diameter and an assumed distance of 2 400 light years gives it a radius of 1 650 R 28 A 2019 paper measurement based on the 641 148 144 pc distance gives the star a lower luminosity below 140 000 L and a correspondingly lower radius of 972 228 R and as well as a lower temperature of 3 551 136 K These parameters are all consistent with those estimated for Betelgeuse 13 The initial mass of Mu Cephei has been estimated from its position relative to theoretical stellar evolutionary tracks to be between 15 M and 25 M 13 14 The star currently has a mass loss rate of 4 9 1 0 10 7 M per year 13 Supernova EditMu Cephei is nearing death It has begun to fuse helium into carbon whereas a main sequence star fuses hydrogen into helium When a supergiant star has converted elements in its core to iron the core collapses to produce a supernova and the star is destroyed leaving behind a vast gaseous cloud and a small dense remnant For a star as massive as Mu Cephei the remnant is likely to be a black hole The most massive red supergiants will evolve back to blue supergiants Luminous blue variables or Wolf Rayet stars before their cores collapse and Mu Cephei appears to be massive enough for this to happen A post red supergiant will produce a type IIn or type II b supernova while a Wolf Rayet star will produce a type Ib or Ic supernova 29 Components EditThere are several faint stars within two arc minutes of Mu Cephei and listed in multiple star catalogues NAME Right ascension Declination Apparent magnitude V Database referencesm Cep B CCDM J21435 5847B 21h 43m 27 8s 58 46 45 12 3m Cep C CCDM J21435 5847C 21h 43m 25 6s 58 47 08 12 7 SimbadSee also EditList of most massive starsReferences Edit a b Perryman M A C et al April 1997 The HIPPARCOS Catalogue Astronomy and Astrophysics 323 L49 L52 Bibcode 1997A amp A 323L 49P a b c Nicolet B October 1978 Catalogue of homogeneous data in the UBV photoelectric photometric system Astronomy amp Astrophysics Supplement Series 34 1 49 Bibcode 1978A amp AS 34 1N a b Samus N N Durlevich O V et al 2009 VizieR Online Data Catalog General Catalogue of Variable Stars Samus 2007 2013 VizieR On line Data Catalog B GCVS Originally Published in 2009yCat 102025S 1 B gcvs Bibcode 2009yCat 102025S a b c Shenoy Dinesh Humphreys Roberta M Terry Jay Jones Marengo Massimo Gehrz Robert D Andrew Helton L Hoffmann William F Skemer Andrew J Hinz Philip M 2015 Searching for Cool Dust in the Mid to Far Infrared The Mass Loss Histories of the Hypergiants m Cep VY CMa IRC 10420 and r Cas The Astronomical Journal 151 3 51 arXiv 1512 01529 Bibcode 2016AJ 151 51S doi 10 3847 0004 6256 151 3 51 S2CID 119281306 a b Keenan Philip C McNeil Raymond C 1989 The Perkins catalog of revised MK types for the cooler stars Astrophysical Journal Supplement Series 71 245 Bibcode 1989ApJS 71 245K doi 10 1086 191373 Shenavrin V I Taranova O G Nadzhip A E 2011 Search for and study of hot circumstellar dust envelopes Astronomy Reports 55 1 31 Bibcode 2011ARep 55 31S doi 10 1134 S1063772911010070 S2CID 122700080 Famaey B et al 2005 Local kinematics of K and M giants from CORAVEL Hipparcos Tycho 2 data Revisiting the concept of superclusters Astronomy and Astrophysics 430 1 165 186 arXiv astro ph 0409579 Bibcode 2005A amp A 430 165F doi 10 1051 0004 6361 20041272 S2CID 17804304 a b Brown A G A et al Gaia collaboration August 2018 Gaia Data Release 2 Summary of the contents and survey properties Astronomy amp Astrophysics 616 A1 arXiv 1804 09365 Bibcode 2018A amp A 616A 1G doi 10 1051 0004 6361 201833051 Gaia DR2 record for this source at VizieR Hipparcos the New Reduction van Leeuwen 2007 a b c d Davies Ben Beasor Emma R March 2020 The red supergiant problem the upper luminosity boundary of Type II supernova progenitors MNRAS 493 1 468 476 arXiv 2001 06020 Bibcode 2020MNRAS 493 468D doi 10 1093 mnras staa174 S2CID 210714093 a b c d e f Table 4 in Emily M Levesque Philip Massey K A G Olsen Bertrand Plez Eric Josselin Andre Maeder amp Georges Meynet 2005 The Effective Temperature Scale of Galactic Red Supergiants Cool but Not As Cool As We Thought The Astrophysical Journal 628 2 973 985 arXiv astro ph 0504337 Bibcode 2005ApJ 628 973L doi 10 1086 430901 S2CID 15109583 a b c Tetzlaff N Neuhauser R Hohle M M January 2011 A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun Monthly Notices of the Royal Astronomical Society 410 1 190 200 arXiv 1007 4883 Bibcode 2011MNRAS 410 190T doi 10 1111 j 1365 2966 2010 17434 x S2CID 118629873 a b c d e f Montarges M Homan W Keller D Clementel N Shetye S Decin L 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