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U Camelopardalis: Difference between revisions

Coordinates: Sky map 03h 41m 48.17393s, +62° 38′ 54.3906″
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{{Short description|Star in the constellation Camelopardalis}}
{{Sky|03|41|48.17393|+|62|38|54.3906}}
{{Sky|03|41|48.17393|+|62|38|54.3906}}
{{Starbox begin

⚫
|name=U Camelopardalis}}
{{Infobox Star
{{Starbox image
| bgcolour = yellow
| name = U Camelopardalis
| image = [[File:U Camelopardalis.jpeg|250px]]
⚫
| caption=U Camelopardalis is a bright star surrounded by a tenuous shell of gas. Its atmosphere contains more carbon than oxygen.
⚫
| image = [[File:U Camelopardalis.jpeg|300px]]
⚫
| caption = U Camelopardalis is a bright star surrounded by a tenuous shell of gas. Its atmosphere contains more carbon than oxygen.
| observation_data = yes
⚫
| epoch = [[J2000]]
⚫
| constellation = [[Camelopardalis (constellation)|Camelopardalis]]<ref name=hubble>{{cite news|title=Red Giant Blows a Bubble|url=http://www.spacetelescope.org/images/potw1227a/|accessdate=3 July 2012|newspaper=ESA/Hubble Picture of the Week}}</ref>
| ra = {{RA|03|41|48.17393}}<ref name=simbad>{{cite web|title=Search Results for U Camelopardalis|url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=U+Camelopardalis|work=Astronomical Database|publisher=SIMBAD|accessdate=3 July 2012}}</ref>
⚫
| dec = {{DEC|+62|38|54.3906}}<ref name=simbad/>
| apparent_magnitude = 7.35<ref name=simbad/>
| absolute_magnitude =
}}
}}
{{Starbox observe
⚫
|constell=[[Camelopardalis]]
⚫
|epoch=[[J2000]]
| ra = {{RA|03|41|48.17393}}<ref name="van Leeuwen2007">{{cite journal | title=Validation of the new Hipparcos reduction | url=http://www.aanda.org/index.php?option=com_article&access=bibcode&Itemid=129&bibcode=2007A%2526A...474..653VFUL | last1=van Leeuwen | first1=F. | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | date=2007 | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 |s2cid = 18759600}}</ref>
⚫
| dec = {{DEC|+62|38|54.3906}}<ref name="van Leeuwen2007"/>
|appmag_v=7.55<ref name=UBV>{{cite journal|author1=Nicolet, B.|title=Catalogue of homogeneous data in the UBV photoelectric photometric system|journal=Astronomy and Astrophysics|volume=34|pages=1–49|date=1978|bibcode=1978A&AS...34....1N}}</ref>
}}
{{Starbox character
|class=C-N5<sub>5.5</sub> (MS4)<ref name=barnbaum>{{cite journal|bibcode=1996ApJS..105..419B|title=A Moderate-Resolution Spectral Atlas of Carbon Stars: R, J, N, CH, and Barium Stars|journal=Astrophysical Journal Supplement |volume=105|page=419|last1=Barnbaum|first1=Cecilia|last2=Stone|first2=Remington P. S.|last3=Keenan|first3=Philip C.|year=1996|doi=10.1086/192323}}</ref>
|b-v=+1.95<ref name=UBV/>
|u-b=+3.50<ref name=UBV/>
|variable=[[Semiregular variable star|SRb]]<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>
}}
{{Starbox astrometry
|radial_v=-3.00<ref name=RV>{{cite journal|url=http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2006AstL...32..759G|title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system|author=Gontcharov, G. A.|date=2006|journal=Astronomy Letters|volume=32|issue=11|pages=759–771|bibcode=2006AstL...32..759G|doi=10.1134/S1063773706110065|arxiv=1606.08053|s2cid=119231169}}</ref>
|prop_mo_ra=3.50<ref name="van Leeuwen2007"/>
|prop_mo_dec=-3.62<ref name="van Leeuwen2007"/>
|parallax=1.03
|p_error=0.59
|parallax_footnote=<ref name="van Leeuwen2007"/>
|dist_pc=530<ref name=guandalini>{{cite journal|bibcode=2006A&A...445.1069G|arxiv=astro-ph/0509739|title=Infrared photometry and evolution of mass-losing AGB stars. I. Carbon stars revisited|journal=Astronomy and Astrophysics|volume=445|issue=3|last1=Guandalini|first1=R.|last2=Busso|first2=M.|last3=Ciprini|first3=S.|last4=Silvestro|first4=G.|last5=Persi|first5=P.|year=2006|pages=1069–1080|doi=10.1051/0004-6361:20053208|s2cid=16797565}}</ref>
|absmag_v=&minus;2.4 (max)<ref name=olson>{{cite journal|bibcode=1975ApJ...200...88O|title=The absolute magnitudes of carbon stars - Carbon stars in binary systems|journal=Astrophysical Journal|volume=200|page=88|last1=Olson|first1=B. I.|last2=Richer|first2=H. B.|year=1975|doi=10.1086/153763|doi-access=free}}</ref>
}}
{{Starbox detail
|temperature=3,000<ref name=tanaka>{{cite journal|bibcode=2007PASJ...59..939T|title=Near-Infrared Spectra of 29 Carbon Stars: Simple Estimates of Effective Temperature|journal=Publications of the Astronomical Society of Japan|volume=59|issue=5|page=939|last1=Tanaka|first1=Masuo|last2=Letip|first2=Ahmatjan|last3=Nishimaki|first3=Yuichirou|last4=Yamamuro|first4=Tomoyasu|last5=Motohara|first5=Kentaro|last6=Miyata|first6=Takashi|last7=Aoki|first7=Wako|year=2007|doi=10.1093/pasj/59.5.939|doi-access=free}}</ref>
|luminosity=8,472<ref name=Bergeat>{{cite journal|author1=Bergeat, J.|author2=Chevallier, L.|date=2005|title=The mass loss of C-rich giants|journal=Astronomy and Astrophysics|volume=429|pages=235–246|bibcode=2005A&A...429..235B|arxiv=astro-ph/0601366|doi=10.1051/0004-6361:20041280|s2cid=56424665}}</ref>
}}
{{Starbox catalog
|names=[[Variable star designation|U]] Cam, [[Bonner Durchmusterung|BD]]+62° 596, [[Henry Draper Catalogue|HD]] 22611, [[Hipparcos catalogue|HIP]] 17257, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]] 12870, [[Boss General Catalogue|GC]] 4371}}
{{Starbox reference
|Simbad=HD+22611}}
{{Starbox end}}
'''U Camelopardalis''' is a [[semiregular variable star|semiregular]] [[variable star|variable]] [[star]] in the [[constellation]] [[Camelopardalis]]. Based on [[stellar parallax|parallax]] measurements made by the [[Hipparcos]] [[spacecraft]], it is located about 3,000 [[light-year]]s (1,000 [[parsec]]s) away from the [[Earth]].<ref name="van Leeuwen2007"/> Its [[apparent magnitude|apparent]] [[visual magnitude]] is about 8, which is dim enough that it cannot be seen with the unaided eye.


The spectral type of U Camelopardalis in the [[Carbon star#The Revised Morgan–Keenan system|revised MK system]] is C-N5, which indicates a classical carbon star spectrum approximately corresponding to late K or early M.<ref name=mk>{{cite journal|bibcode=1993PASP..105..905K|title=Revised MK spectral classification of the red carbon stars|journal=Astronomical Society of the Pacific|volume=105|page=905|last1=Keenan|first1=Philip C.|year=1993|doi=10.1086/133252|doi-access=free}}</ref> The C<sub>2</sub> index is 5.5 which is typical of a C-N star.<ref name=mk1941>{{cite journal|author1=Keenan, P. C.|author2=Morgan, W. W.|date=1941|title=The Classification of the Red Carbon Stars|journal=[[The Astrophysical Journal]]|volume=94|page=501|bibcode=1941ApJ....94..501K|doi=10.1086/144356}}</ref> It is also given an alternative spectral type of [[S-type star|MS4]], indicating a star similar to an M4 class but with somewhat enhanced ZrO bands.<ref name=barnbaum/> The spectral type may vary between C3,9 and C6,4e.<ref name=gcvs/>
'''U Camelopardalis''', or '''U Cam''', is a [[carbon star]] located 1500 light years away in the constellation of [[Camelopardalis (constellation)|Camelopardalis]], near the North Celestial Pole.<ref>{{cite web|url=http://www.nasa.gov/multimedia/imagegallery/image_feature_2302.html |title=NASA - Hubble Sees Red Giant Blow a Bubble |publisher=Nasa.gov |date=2012-07-06 |accessdate=2012-10-28}}</ref>

[[File:UCamLightCurve.png|thumb|left|A [[Photometric_system#Photometric_letters|visual band]] [[light curve]] for U Camelopardalis, plotted from AAVSO data<ref name="aavso"/>]]
U Camelopardalis is a [[carbon star]]. These types of stars have greater levels of [[carbon]] in their atmospheres than [[oxygen]], which means they form carbon compounds that make the star appear strikingly red. U Camelopardalis is nearly 4 magnitudes fainter at blue wavelengths than in the centre of the visual range. In the [[infrared]] [[K band (infrared)|K band]] it has an apparent magnitude of 0.37.<ref name=knapp/> Its brightness varies without a dominant period and it is classified as [[Semiregular variable star|semi-regular]], although a period of 400 days has been published.<ref name=knapp>{{cite journal|bibcode=2003A&A...403..993K|title=Reprocessing the Hipparcos data of evolved stars. III. Revised Hipparcos period-luminosity relationship for galactic long-period variable stars|journal=Astronomy and Astrophysics|volume=403|issue=3|last1=Knapp|first1=G. R.|last2=Pourbaix|first2=D.|last3=Platais|first3=I.|last4=Jorissen|first4=A.|year=2003|pages=993–1002|doi=10.1051/0004-6361:20030429|arxiv = astro-ph/0301579 |s2cid=5603380}}</ref> In the [[UBV photometric system|V photometric band]] the brightness varies by around half a magnitude,<ref name=adelman>{{cite journal|bibcode=2001BaltA..10..589A|title=Stars with the Largest Hipparcos Photometric Amplitudes|journal=Baltic Astronomy|volume=10|page=589|last1=Adelman|first1=Saul J.|year=2001|issue=4 |doi=10.1515/astro-2001-0403 |s2cid=116386247 |doi-access=free}}</ref> but the amplitude is nearly two magnitudes at blue wavelengths.<ref name=gcvs/> The maximum visual magnitude has been given as 7.2.<ref name=olson/>

⚫
The shell of gas surrounding U Camelopardalis was imaged by the [[Hubble Space Telescope]] in 2012, showing a nearly perfect sphere of gas surrounding the star.<ref>{{cite news|title=Red Giant Blows a Bubble|url=http://www.spacetelescope.org/images/potw1227a/|access-date=18 February 2017|newspaper=ESA/Hubble Picture of the Week}}</ref>

U Cameloparadlis has a 10th magnitude companion 308" away. It is a B8 [[main sequence]] star, hotter but less luminous than U Cam itself. They are not thought to be physically associated.<ref name=olson/>


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


<ref name="aavso">{{cite web |title=Download Data |url=https://www.aavso.org/data-download |website=aavso.org |publisher=AAVSO |access-date=1 October 2021}}</ref>
⚫
{{Stars of Camelopardalis}}


}}
{{star-stub}}

{{Stars of Camelopardalis}}


{{DEFAULTSORT:U Camelopardalis}}
⚫
[[Category:C-type stars]]
[[Category:Camelopardalis (constellation)]]
[[Category:Carbon stars]]
[[Category:Objects named with variable star designations|Camelopardalis, U]]
[[Category:Camelopardalis]]
[[Category:Objects with variable star designations|Camelopardalis, U]]
[[Category:Henry Draper Catalogue objects|022611]]
[[Category:Henry Draper Catalogue objects|022611]]
[[Category:Hipparcos objects|017257]]
[[Category:Durchmusterung objects]]
⚫
[[Category:Semiregular variable stars]]
[[Category:Asymptotic-giant-branch stars]]

Latest revision as of 21:50, 13 August 2023

U Camelopardalis

U Camelopardalis is a bright star surrounded by a tenuous shell of gas. Its atmosphere contains more carbon than oxygen.
Observation data
Epoch J2000      Equinox J2000
Constellation Camelopardalis
Right ascension 03h 41m 48.17393s[1]
Declination +62° 38′ 54.3906″[1]
Apparent magnitude (V) 7.55[2]
Characteristics
Spectral type C-N55.5 (MS4)[3]
U−B color index +3.50[2]
B−V color index +1.95[2]
Variable type SRb[4]
Astrometry
Radial velocity (Rv)-3.00[5] km/s
Proper motion (μ) RA: 3.50[1] mas/yr
Dec.: -3.62[1] mas/yr
Parallax (π)1.03 ± 0.59 mas[1]
Distance530[6] pc
Absolute magnitude (MV)−2.4 (max)[7]
Details
Luminosity8,472[8] L☉
Temperature3,000[9] K
Other designations
U Cam, BD+62° 596, HD 22611, HIP 17257, SAO 12870, GC 4371
Database references
SIMBADdata

U Camelopardalis is a semiregular variable star in the constellation Camelopardalis. Based on parallax measurements made by the Hipparcos spacecraft, it is located about 3,000 light-years (1,000 parsecs) away from the Earth.[1] Its apparent visual magnitude is about 8, which is dim enough that it cannot be seen with the unaided eye.

The spectral type of U Camelopardalis in the revised MK system is C-N5, which indicates a classical carbon star spectrum approximately corresponding to late K or early M.[10] The C2 index is 5.5 which is typical of a C-N star.[11] It is also given an alternative spectral type of MS4, indicating a star similar to an M4 class but with somewhat enhanced ZrO bands.[3] The spectral type may vary between C3,9 and C6,4e.[4]

A visual band light curve for U Camelopardalis, plotted from AAVSO data[12]

U Camelopardalis is a carbon star. These types of stars have greater levels of carbon in their atmospheres than oxygen, which means they form carbon compounds that make the star appear strikingly red. U Camelopardalis is nearly 4 magnitudes fainter at blue wavelengths than in the centre of the visual range. In the infrared K band it has an apparent magnitude of 0.37.[13] Its brightness varies without a dominant period and it is classified as semi-regular, although a period of 400 days has been published.[13] In the V photometric band the brightness varies by around half a magnitude,[14] but the amplitude is nearly two magnitudes at blue wavelengths.[4] The maximum visual magnitude has been given as 7.2.[7]

The shell of gas surrounding U Camelopardalis was imaged by the Hubble Space Telescope in 2012, showing a nearly perfect sphere of gas surrounding the star.[15]

U Cameloparadlis has a 10th magnitude companion 308" away. It is a B8 main sequence star, hotter but less luminous than U Cam itself. They are not thought to be physically associated.[7]

References

[edit]
  1. ^ a b c d e f 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.
  2. ^ a b c Nicolet, B. (1978). "Catalogue of homogeneous data in the UBV photoelectric photometric system". Astronomy and Astrophysics. 34: 1–49. Bibcode:1978A&AS...34....1N.
  3. ^ a b Barnbaum, Cecilia; Stone, Remington P. S.; Keenan, Philip C. (1996). "A Moderate-Resolution Spectral Atlas of Carbon Stars: R, J, N, CH, and Barium Stars". Astrophysical Journal Supplement. 105: 419. Bibcode:1996ApJS..105..419B. doi:10.1086/192323.
  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. ^ 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.
  6. ^ Guandalini, R.; Busso, M.; Ciprini, S.; Silvestro, G.; Persi, P. (2006). "Infrared photometry and evolution of mass-losing AGB stars. I. Carbon stars revisited". Astronomy and Astrophysics. 445 (3): 1069–1080. arXiv:astro-ph/0509739. Bibcode:2006A&A...445.1069G. doi:10.1051/0004-6361:20053208. S2CID 16797565.
  7. ^ a b c Olson, B. I.; Richer, H. B. (1975). "The absolute magnitudes of carbon stars - Carbon stars in binary systems". Astrophysical Journal. 200: 88. Bibcode:1975ApJ...200...88O. doi:10.1086/153763.
  8. ^ Bergeat, J.; Chevallier, L. (2005). "The mass loss of C-rich giants". Astronomy and Astrophysics. 429: 235–246. arXiv:astro-ph/0601366. Bibcode:2005A&A...429..235B. doi:10.1051/0004-6361:20041280. S2CID 56424665.
  9. ^ Tanaka, Masuo; Letip, Ahmatjan; Nishimaki, Yuichirou; Yamamuro, Tomoyasu; Motohara, Kentaro; Miyata, Takashi; Aoki, Wako (2007). "Near-Infrared Spectra of 29 Carbon Stars: Simple Estimates of Effective Temperature". Publications of the Astronomical Society of Japan. 59 (5): 939. Bibcode:2007PASJ...59..939T. doi:10.1093/pasj/59.5.939.
  10. ^ Keenan, Philip C. (1993). "Revised MK spectral classification of the red carbon stars". Astronomical Society of the Pacific. 105: 905. Bibcode:1993PASP..105..905K. doi:10.1086/133252.
  11. ^ Keenan, P. C.; Morgan, W. W. (1941). "The Classification of the Red Carbon Stars". The Astrophysical Journal. 94: 501. Bibcode:1941ApJ....94..501K. doi:10.1086/144356.
  12. ^ "Download Data". aavso.org. AAVSO. Retrieved 1 October 2021.
  13. ^ a b Knapp, G. R.; Pourbaix, D.; Platais, I.; Jorissen, A. (2003). "Reprocessing the Hipparcos data of evolved stars. III. Revised Hipparcos period-luminosity relationship for galactic long-period variable stars". Astronomy and Astrophysics. 403 (3): 993–1002. arXiv:astro-ph/0301579. Bibcode:2003A&A...403..993K. doi:10.1051/0004-6361:20030429. S2CID 5603380.
  14. ^ Adelman, Saul J. (2001). "Stars with the Largest Hipparcos Photometric Amplitudes". Baltic Astronomy. 10 (4): 589. Bibcode:2001BaltA..10..589A. doi:10.1515/astro-2001-0403. S2CID 116386247.
  15. ^ "Red Giant Blows a Bubble". ESA/Hubble Picture of the Week. Retrieved 18 February 2017.
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