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{{Short description|Star in the constellation Cepheus}}
{{Starbox begin
{{Starbox begin
| name = Nu Cephei
| name = Nu Cephei
⚫
}}
{{Starbox image
| image = [[Image:NuCepLightCurve.png|250px]]
| caption = A [[light curve]] for Nu Cephei, plotted from ''[[Transiting Exoplanet Survey Satellite|TESS]]'' data,<ref name=MAST/>
}}
}}
{{Starbox observe
{{Starbox observe
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| j-k =
| j-k =
| variable = [[Alpha Cygni variable|Alpha Cygni]]<ref name=gcvs/>
| variable = [[Alpha Cygni variable|Alpha Cygni]]<ref name=gcvs/>
|type=[[Blue supergiant]]<ref name=yuce/>}}
⚫
}}
{{Starbox astrometry
{{Starbox astrometry
| radial_v = −25.90<ref name=famaey/>
| radial_v = −25.90<ref name=famaey/>
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{{Starbox detail
{{Starbox detail
| source =
| source =
| mass = 16.5<ref name=firnstein2010/>
| mass = 15.4<ref name=firnstein2010/>
| radius = 137<ref name=firnstein2010/>
| radius = 137<ref name=firnstein2010/>
| gravity = 1.35<ref name=firnstein/>
| gravity = 1.35<ref name=firnstein/>
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{{Starbox end}}
{{Starbox end}}


'''Nu Cephei''' (ν Cephei) is a [[Stellar classification|class A2]], fourth-magnitude [[supergiant]] [[star]] in the [[constellation]] [[Cepheus (constellation)|Cepheus]]. It is a white pulsating [[Alpha Cygni variable|α Cygni variable star]] located about 4,700 [[light-year]]s from Earth.
'''Nu Cephei''' (ν Cephei) is a [[Stellar classification|class A2]], fourth-magnitude [[blue supergiant]] [[star]] in the [[constellation]] [[Cepheus (constellation)|Cepheus]], visible to the [[naked eye]]. It is a white pulsating [[Alpha Cygni variable|α Cygni variable star]] located about 4,700 [[light-year]]s from Earth.


ν Cephei is a member of the Cepheus OB2 [[stellar association]],<ref name=yuce/> which includes stars such as [[Mu Cephei|μ Cephei]] and [[VV Cephei]].<ref name=humphreys/> It began life as an approximately {{solar mass|20}}<ref name=firnstein2010/><ref name=yuce/> star around eight million years ago. It has now exhausted its core hydrogen and expanded and cooled into a supergiant. Elemental abundance analyes indicate that it has not yet spent time as a red supergiant, which would have brought about convection of fusion products to the surface in a [[Dredge-up]].<ref name=yuce/>
ν Cephei is a member of the Cepheus OB2 [[stellar association]],<ref name=yuce/> which includes stars such as [[Mu Cephei|μ Cephei]] and [[VV Cephei]].<ref name=humphreys/> It began life as an approximately {{solar mass|20}}<ref name=firnstein2010/><ref name=yuce/> star around eight million years ago. It has now exhausted its core hydrogen and expanded and cooled into a supergiant. Elemental abundance analyses indicate that it has not yet spent time as a red supergiant, which would have brought about convection of fusion products to the surface in a [[Dredge-up]].<ref name=yuce/>


ν Cephei is currently about 15 times as massive as the sun, 190 times as large, and 100,000 times as luminous. Its large size and luminosity cause it to be somewhat unstable and produce irregular pulsations. This is a common feature of class A and B supergiants, which are grouped as [[Alpha Cygni variable|α Cygni variable star]]s. The brightness changes by at most a tenth of a magnitude.<ref name=gcvs/>
ν Cephei is currently about 15 times as massive as the sun, 190 times as large, and 100,000 times as luminous. Its large size and luminosity cause it to be somewhat unstable and produce irregular pulsations. This is a common feature of class A and B supergiants, which are grouped as [[Alpha Cygni variable|α Cygni variable star]]s. Variability was first reported by [[Helmut Abt]] in 1957.<ref name="Abt"/> The brightness changes by at most a tenth of a magnitude.<ref name=gcvs/> A variety of values for the variability period have been published, including 5 to 10 days,<ref name="Percy"/> 7.6 days<ref name="Buscombe"/><ref name="Abt"/> and 90 days.<ref name="ivsi"/>


== References ==
== References ==
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{{reflist|refs=
{{reflist|refs=


<ref name=MAST>{{cite web
⚫
<ref name="van Leeuwen2007">{{cite journal | title=Validation of the new Hipparcos reduction | url=http://www.aanda.org/articles/aa/full/2007/41/aa8357-07/aa8357-07.html | last1=van Leeuwen | first1=F. | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | year=2007 | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 }}[http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I/311/hip2&recno=107052 Vizier catalog entry ]</ref>
| title=MAST: Barbara A. Mikulski Archive for Space Telescopes
| url=https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html
| publisher=Space Telescope Science Institute | access-date=27 September 2024}}</ref>

<ref name="Abt">{{cite journal |last1=Abt |first1=Helmut A. |title=The Variability of Supergiants |journal=Astrophysical Journal |date=July 1957 |volume=126 |pages=138-151 |bibcode=1957ApJ...126..138A |doi=10.1086/146379 |url=https://articles.adsabs.harvard.edu/pdf/1957ApJ...126..138A |access-date=29 September 2024}}</ref>

<ref name="Percy">{{cite journal |last1=Percy |first1=J. R. |last2=Welch |first2=D. L. |title=Photometric variability of B- and A-type supergiants |journal=Publications of the Astronomical Society of the Pacific |date=August 1983 |volume=95 |pages=491-505 |doi=10.1086/131198 |bibcode=1983PASP...95..491P |url=https://articles.adsabs.harvard.edu/pdf/1983PASP...95..491P |access-date=29 September 2024}}</ref>

<ref name="Buscombe">{{cite journal |last1=Buscombe |first1=W. |title=Variations in the spectra of A-type supergiants |journal=The Observatory |date=June 1974 |volume=94 |pages=120-122 |bibcode=1974Obs....94..120B |url=https://articles.adsabs.harvard.edu/pdf/1974Obs....94..120B |access-date=29 September 2024}}</ref>

<ref name="ivsi">{{cite web |title=nu. Cep |url=https://www.aavso.org/vsx/index.php?view=detail.top&oid=9070 |website=The International Variable Star Index |publisher=AAVSO |access-date=29 September 2024}}</ref>

⚫
<ref name="van Leeuwen2007">{{cite journal | title=Validation of the new Hipparcos reduction | url=http://www.aanda.org/articles/aa/full/2007/41/aa8357-07/aa8357-07.html | last1=van Leeuwen | first1=F. | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | year=2007 | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | s2cid=18759600 }}[http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I/311/hip2&recno=107052 Vizier catalog entry ]</ref>


<ref name=firnstein>{{cite journal|bibcode=2012A&A...543A..80F|arxiv=1207.0308|title=Quantitative spectroscopy of Galactic BA-type supergiants. I. Atmospheric parameters|journal=Astronomy & Astrophysics|volume=543|pages=A80|author1=Firnstein|first1=M.|last2=Przybilla|first2=N.|year=2012|doi=10.1051/0004-6361/201219034}}</ref>
<ref name=firnstein>{{cite journal|bibcode=2012A&A...543A..80F|arxiv=1207.0308|title=Quantitative spectroscopy of Galactic BA-type supergiants. I. Atmospheric parameters|journal=Astronomy & Astrophysics|volume=543|pages=A80|last1=Firnstein|first1=M.|last2=Przybilla|first2=N.|year=2012|doi=10.1051/0004-6361/201219034|s2cid=54725386}}</ref>


<ref name=gcvs>{{cite journal|bibcode=2009yCat....102025S|title=VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)|journal=VizieR On-line Data Catalog: B/gcvs. Originally published in: 2009yCat....102025S|volume=1|display-authors=etal|author1=Samus|first1=N. N.|last2=Durlevich|first2=O. V.|year=2009}}</ref>
<ref name=gcvs>{{cite journal|bibcode=2009yCat....102025S|title=VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)|journal=VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S|volume=1|display-authors=etal|last1=Samus|first1=N. N.|last2=Durlevich|first2=O. V.|year=2009}}</ref>


<ref name=ducati>{{cite journal|bibcode=2002yCat.2237....0D|title=VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system|journal=CDS/ADC Collection of Electronic Catalogues|volume=2237|author1=Ducati|first1=J. R.|year=2002}}</ref>
<ref name=ducati>{{cite journal|bibcode=2002yCat.2237....0D|title=VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system|journal=CDS/ADC Collection of Electronic Catalogues|volume=2237|last1=Ducati|first1=J. R.|year=2002}}</ref>


<ref name=famaey>{{cite journal|bibcode=2006AstL...32..759G|title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system|journal=Astronomy Letters|volume=32|issue=11|pages=759|author1=Gontcharov|first1=G. A.|year=2006|doi=10.1134/S1063773706110065}}</ref>
<ref name=famaey>{{cite journal|bibcode=2006AstL...32..759G|title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system|journal=Astronomy Letters|volume=32|issue=11|pages=759–771|last1=Gontcharov|first1=G. A.|year=2006|doi=10.1134/S1063773706110065|arxiv = 1606.08053 |s2cid=119231169}}</ref>


<ref name=verdugo>{{cite journal|bibcode=1999A&A...346..819V|title=Understanding A-type supergiants. II. Atmospheric parameters and rotational velocities of Galactic A-type supergiants|journal=Astronomy and Astrophysics|volume=346|pages=819|author1=Verdugo|first1=E.|last2=Talavera|first2=A.|last3=Gómez De Castro|first3=A. I.|year=1999}}</ref>
<ref name=verdugo>{{cite journal|bibcode=1999A&A...346..819V|title=Understanding A-type supergiants. II. Atmospheric parameters and rotational velocities of Galactic A-type supergiants|journal=Astronomy and Astrophysics|volume=346|pages=819|last1=Verdugo|first1=E.|last2=Talavera|first2=A.|last3=Gómez De Castro|first3=A. I.|year=1999}}</ref>


<ref name=yuce>{{cite journal|bibcode=2005BaltA..14...51Y|title=Spectral Analysis of 4 Lacertae and ν Cephei|journal=Baltic Astronomy|volume=14|pages=51|author1=Yüce|first1=Kutluay|year=2005}}</ref>
<ref name=yuce>{{cite journal|bibcode=2005BaltA..14...51Y|title=Spectral Analysis of 4 Lacertae and ν Cephei|journal=Baltic Astronomy|volume=14|pages=51|last1=Yüce|first1=Kutluay|year=2005}}</ref>


<ref name=firnstein2010>{{cite thesis |type=Ph.D. |last=Firnstein |first=Markus |date=2010 |title=Quantitative Spectroscopy of Galactic BA-Type Supergiants |publisher=Erlangen, Nürnberg, Univ}}</ref>
<ref name=firnstein2010>{{cite thesis |type=Ph.D. |last=Firnstein |first=Markus |date=2010 |title=Quantitative Spectroscopy of Galactic BA-Type Supergiants |publisher=Erlangen, Nürnberg, Univ}}</ref>


<ref name=humphreys>{{cite journal|bibcode=1978ApJS...38..309H|title=Studies of luminous stars in nearby galaxies. I. Supergiants and O stars in the Milky Way|journal=Astrophysical Journal|volume=38|pages=309|author1=Humphreys|first1=R. M.|year=1978|doi=10.1086/190559}}</ref>
<ref name=humphreys>{{cite journal|bibcode=1978ApJS...38..309H|title=Studies of luminous stars in nearby galaxies. I. Supergiants and O stars in the Milky Way|journal=Astrophysical Journal|volume=38|pages=309|last1=Humphreys|first1=R. M.|year=1978|doi=10.1086/190559}}</ref>


}}
}}
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{{Stars of Cepheus}}
{{Stars of Cepheus}}


{{DEFAULTSORT:Nu Cephei}}
[[Category:Bayer objects|Cephei, Nu]]
[[Category:Bayer objects|Cephei, Nu]]
[[Category:Henry Draper Catalogue objects|207260]]
[[Category:Henry Draper Catalogue objects|207260]]
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[[Category:Flamsteed objects|Cephei, 10]]
[[Category:Flamsteed objects|Cephei, 10]]
[[Category:Hipparcos objects|107418]]
[[Category:Hipparcos objects|107418]]
[[Category:HR objects|8335]]
[[Category:Bright Star Catalogue objects|8335]]
[[Category:Durchmusterung objects]]

Latest revision as of 16:04, 29 September 2024

Nu Cephei

A light curve for Nu Cephei, plotted from TESS data,[1]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cepheus
Right ascension 21h 45m 26.925s[2]
Declination +61° 07′ 14.90″[2]
Apparent magnitude (V) 4.289[3] (4.25 - 4.35[4])
Characteristics
Evolutionary stage Blue supergiant[5]
Spectral type A2Iab[3]
Apparent magnitude (U) 4.94[6]
Apparent magnitude (B) 4.81[6]
Apparent magnitude (J) 3.14[6]
Apparent magnitude (K) 2.85[6]
U−B color index +0.119[3]
B−V color index +0.518[3]
Variable type Alpha Cygni[4]
Astrometry
Radial velocity (Rv)−25.90[7] km/s
Proper motion (μ) RA: −3.74 ± 0.13[2] mas/yr
Dec.: −2.10 ± 0.12[2] mas/yr
Parallax (π)0.48 ± 0.14 mas[2]
Distance1,450[8] pc
Absolute magnitude (MV)−6.82[9]
Details
Mass15.4[8] M☉
Radius137[8] R☉
Luminosity102,000[8] L☉
Surface gravity (log g)1.35[3] cgs
Temperature8,800[3] K
Rotational velocity (v sin i)15[3] km/s
Age8[5] Myr
Other designations
10 Cephei, HD 207260, HR 8334, SAO 19624, FK5 1572, BD+60°2288, HIP 107418
Database references
SIMBADdata

Nu Cephei (ν Cephei) is a class A2, fourth-magnitude blue supergiant star in the constellation Cepheus, visible to the naked eye. It is a white pulsating α Cygni variable star located about 4,700 light-years from Earth.

ν Cephei is a member of the Cepheus OB2 stellar association,[5] which includes stars such as μ Cephei and VV Cephei.[10] It began life as an approximately 20 M☉[8][5] star around eight million years ago. It has now exhausted its core hydrogen and expanded and cooled into a supergiant. Elemental abundance analyses indicate that it has not yet spent time as a red supergiant, which would have brought about convection of fusion products to the surface in a Dredge-up.[5]

ν Cephei is currently about 15 times as massive as the sun, 190 times as large, and 100,000 times as luminous. Its large size and luminosity cause it to be somewhat unstable and produce irregular pulsations. This is a common feature of class A and B supergiants, which are grouped as α Cygni variable stars. Variability was first reported by Helmut Abt in 1957.[11] The brightness changes by at most a tenth of a magnitude.[4] A variety of values for the variability period have been published, including 5 to 10 days,[12] 7.6 days[13][11] and 90 days.[14]

References

[edit]
  1. ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 27 September 2024.
  2. ^ a b c d e van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.Vizier catalog entry
  3. ^ a b c d e f g Firnstein, M.; Przybilla, N. (2012). "Quantitative spectroscopy of Galactic BA-type supergiants. I. Atmospheric parameters". Astronomy & Astrophysics. 543: A80. arXiv:1207.0308. Bibcode:2012A&A...543A..80F. doi:10.1051/0004-6361/201219034. S2CID 54725386.
  4. ^ a b c 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. Bibcode:2009yCat....102025S.
  5. ^ a b c d e Yüce, Kutluay (2005). "Spectral Analysis of 4 Lacertae and ν Cephei". Baltic Astronomy. 14: 51. Bibcode:2005BaltA..14...51Y.
  6. ^ a b c d Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
  7. ^ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
  8. ^ a b c d e Firnstein, Markus (2010). Quantitative Spectroscopy of Galactic BA-Type Supergiants (Ph.D.). Erlangen, Nürnberg, Univ.
  9. ^ Verdugo, E.; Talavera, A.; Gómez De Castro, A. I. (1999). "Understanding A-type supergiants. II. Atmospheric parameters and rotational velocities of Galactic A-type supergiants". Astronomy and Astrophysics. 346: 819. Bibcode:1999A&A...346..819V.
  10. ^ Humphreys, R. M. (1978). "Studies of luminous stars in nearby galaxies. I. Supergiants and O stars in the Milky Way". Astrophysical Journal. 38: 309. Bibcode:1978ApJS...38..309H. doi:10.1086/190559.
  11. ^ a b Abt, Helmut A. (July 1957). "The Variability of Supergiants". Astrophysical Journal. 126: 138–151. Bibcode:1957ApJ...126..138A. doi:10.1086/146379. Retrieved 29 September 2024.
  12. ^ Percy, J. R.; Welch, D. L. (August 1983). "Photometric variability of B- and A-type supergiants". Publications of the Astronomical Society of the Pacific. 95: 491–505. Bibcode:1983PASP...95..491P. doi:10.1086/131198. Retrieved 29 September 2024.
  13. ^ Buscombe, W. (June 1974). "Variations in the spectra of A-type supergiants". The Observatory. 94: 120–122. Bibcode:1974Obs....94..120B. Retrieved 29 September 2024.
  14. ^ "nu. Cep". The International Variable Star Index. AAVSO. Retrieved 29 September 2024.
[edit]
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