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{{short description|Solitary red clump giant star in the constellation Eridanus}} |
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{{starbox short |
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{{Starbox begin |
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|constell= [[Eridanus (constellation)|Eridanus]] |
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|name= |
| name = [[Bayer designation|ι Eridani]]}} |
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{{Starbox observe |
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|type= K0III <ref name=SIMBAD> SIMBAD, [http://simbak.cfa.harvard.edu/simbad/sim-basic?Ident=Iota+Eridani&submit=SIMBAD+search Iota Eridani] (accessed 11 September 2012) </ref> |
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| epoch = [[J2000.0]] |
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|ra= {{RA|02|40|40.03501}} <ref name=SIMBAD/> |
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| equinox = [[J2000.0]] ([[International Celestial Reference System|ICRS]]) |
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|dec= {{DEC|−39|51|19.3541}} <ref name=SIMBAD/> |
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| constell = [[Eridanus (constellation)|Eridanus]] |
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| ra = {{RA|02|40|40.03501}}<ref name=vanLeeuwen2007/> |
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| dec = {{DEC|−39|51|19.3541}}<ref name=vanLeeuwen2007/> |
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| appmag_v = 4.11<ref name=Johnson1996/> |
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}} |
}} |
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{{Starbox character |
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'''Iota Eridani''' ('''ι Eri''') is a [[star]] in the [[constellation]] [[Eridanus (constellation)|Eridanus]]. Its [[apparent magnitude]] is 4.12. |
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| type = [[Red clump]]<ref name=Liu2007/> |
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| class = K0 III<ref name=houk1978/> |
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| u-b = +0.74<ref name=Johnson1996/> |
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| b-v = +1.02<ref name=Johnson1996/> |
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| r-i = |
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}} |
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{{Starbox astrometry |
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| radial_v = {{Val|−9.30|0.70}}<ref name=deBruijne2012/> |
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| prop_mo_ra = +135.92<ref name=vanLeeuwen2007/> |
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| prop_mo_dec = −27.53<ref name=vanLeeuwen2007/> |
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| parallax = 21.65 |
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| p_error = 0.18 |
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| parallax_footnote = <ref name=vanLeeuwen2007/> |
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| absmag_v= 0.877<ref name=Liu2007/> |
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}} |
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{{Starbox detail |
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| source = <ref name=Gallenne2017/> |
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| mass = {{val|1.29|0.01}} |
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| radius = {{val|11.17|0.06}} |
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| luminosity = {{val|54.7|0.5}} |
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| temperature = {{val|4700|30|fmt=commas}} |
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| gravity = {{val|2.65|0.10}} |
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| metal_fe = {{Val|-0.34|0.02}} |
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| rotational_velocity = |
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| age_gyr = {{val|3.55|0.12}} |
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}} |
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{{Starbox catalog |
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| names = ι Eri, [[Cordoba Durchmusterung|CD]]−40° 689, [[Catalogues of Fundamental Stars|FK5]] 1075, [[Henry Draper Catalogue|HD]] 16815, [[Hipparcos Catalogue|HIP]] 12486, [[Bright Star Catalogue|HR]] 794, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]] 215999.<ref name=SIMBAD/> |
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}} |
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{{Starbox reference |
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| Simbad = iot+Eri |
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}} |
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{{Starbox end}} |
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'''Iota Eridani''' ('''ι Eri''') is a solitary [[star]] in the [[constellation]] [[Eridanus (constellation)|Eridanus]]. It is visible to the naked eye with an [[apparent magnitude]] of 4.11.<ref name=Johnson1996/> With an annual [[stellar parallax|parallax shift]] of 0.02165 [[arcsecond]]s,<ref name=vanLeeuwen2007/> it lies at an estimated distance of about 151 [[light year]]s. |
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This is an [[stellar evolution|evolved]] [[giant star]] with a [[stellar classification]] of K0 III.<ref name=houk1978/> The measured [[angular diameter]], after correcting for [[limb darkening]], is {{Val|2.248|0.014|u=[[milliarcsecond|mas]]}}. This star is 3.55 billion years old, sufficient to have exhausted the hydrogen at its core and reached a [[red clump]] stage. It is only around 29% more massive than the Sun, but is eleven times larger. It radiates 54.7 times the [[solar luminosity]] from its [[stellar atmosphere|outer atmosphere]] at an [[effective temperature]] of 4,700 K.<ref name=Gallenne2017/> |
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==References== |
==References== |
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{{reflist |
{{reflist|refs= |
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<ref name=vanLeeuwen2007>{{citation |
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{{Stars of Eridanus}} |
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| title=Validation of the new Hipparcos reduction |
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| last1=van Leeuwen | first1=F. |
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| journal=Astronomy and Astrophysics |
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| volume=474 | issue=2 | pages=653–664 | date=2007 |
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| arxiv=0708.1752 | bibcode=2007A&A...474..653V |
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| doi=10.1051/0004-6361:20078357 | s2cid=18759600 | postscript=. }}</ref> |
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<ref name=houk1978>{{citation |
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[[Category:Eridanus (constellation)]] |
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| last1=Houk | first1=Nancy | year=1978 |
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| title=Michigan catalogue of two-dimensional spectral types for the HD stars |
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| volume=2 | location=Ann Arbor |
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| publisher=Dept. of Astronomy, University of Michigan |
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| bibcode=1978mcts.book.....H | postscript=. }}</ref> |
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<ref name=deBruijne2012>{{citation |
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| last1=de Bruijne | first1=J. H. J. | last2=Eilers | first2=A.-C. |
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| title=Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project |
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| journal=Astronomy & Astrophysics |
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| volume=546 | id=A61 | pages=14 | date=October 2012 |
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| doi=10.1051/0004-6361/201219219 | bibcode=2012A&A...546A..61D |
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| arxiv=1208.3048 | s2cid=59451347 | postscript=. }}</ref> |
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<ref name=Liu2007>{{citation |
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| display-authors=1 | last1=Liu | first1=Y. J. |
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| last2=Zhao | first2=G. | last3=Shi | first3=J. R. |
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| last4=Pietrzyński | first4=G. | last5=Gieren | first5=W. |
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| title=The abundances of nearby red clump giants |
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| journal=Monthly Notices of the Royal Astronomical Society |
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| volume=382 | issue=2 | pages=553–66 | date=2007 |
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| bibcode=2007MNRAS.382..553L | doi=10.1111/j.1365-2966.2007.11852.x |
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| doi-access=free }}</ref> |
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<ref name=Gallenne2017>{{Citation |last=Gallenne |first=A. |last2=Pietrzyński |first2=G. |last3=Graczyk |first3=D. |last4=Nardetto |first4=N. |last5=Mérand |first5=A. |last6=Kervella |first6=P. |last7=Gieren |first7=W. |last8=Villanova |first8=S. |last9=Mennickent |first9=R. E. |last10=Pilecki |first10=B. |date=2018-08-01 |title=Fundamental properties of red-clump stars from long-baseline H-band interferometry |journal=[[Astronomy & Astrophysics]] |arxiv=1806.09572 |language=en |volume=616 |pages=A68 |doi=10.1051/0004-6361/201833341 |issn=0004-6361}}</ref> |
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<ref name=Johnson1996>{{citation |
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| display-authors=1 |
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| last1=Johnson | first1=H. L. | last2=Iriarte | first2=B. |
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| last3=Mitchell | first3=R. I. | last4=Wisniewskj | first4=W. Z. |
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| title=UBVRIJKL photometry of the bright stars |
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| journal=Communications of the Lunar and Planetary Laboratory |
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| volume=4 | issue=99 | year=1966 | page=99 | doi=| arxiv= |
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| bibcode=1966CoLPL...4...99J | s2cid=| postscript=. }}</ref> |
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<ref name=SIMBAD>{{cite simbad |
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| title=iot Eri |
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| access-date=2016-10-29 | postscript=. }}</ref> |
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}} |
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{{Stars of Eridanus|state=collapsed}} |
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{{DEFAULTSORT:Iota Eridani}} |
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[[Category:K-type giants]] |
[[Category:K-type giants]] |
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[[Category:Horizontal-branch stars]] |
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[[Category:Eridanus (constellation)]] |
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[[Category:Bayer objects|Eridani, Iota]] |
[[Category:Bayer objects|Eridani, Iota]] |
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[[Category:Henry Draper Catalogue objects|016815]] |
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[[Category:Hipparcos objects|012486]] |
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{{Star-stub}} |
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[[Category:Bright Star Catalogue objects|0794]] |
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[[Category:Durchmusterung objects]] |
Latest revision as of 15:02, 22 September 2024
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
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Constellation | Eridanus |
Right ascension | 02h 40m 40.03501s[1] |
Declination | −39° 51′ 19.3541″[1] |
Apparent magnitude (V) | 4.11[2] |
Characteristics | |
Evolutionary stage | Red clump[3] |
Spectral type | K0 III[4] |
U−B color index | +0.74[2] |
B−V color index | +1.02[2] |
Astrometry | |
Radial velocity (Rv) | −9.30±0.70[5] km/s |
Proper motion (μ) | RA: +135.92[1] mas/yr Dec.: −27.53[1] mas/yr |
Parallax (π) | 21.65 ± 0.18 mas[1] |
Distance | 151 ± 1 ly (46.2 ± 0.4 pc) |
Absolute magnitude (MV) | 0.877[3] |
Details[6] | |
Mass | 1.29±0.01 M☉ |
Radius | 11.17±0.06 R☉ |
Luminosity | 54.7±0.5 L☉ |
Surface gravity (log g) | 2.65±0.10 cgs |
Temperature | 4,700±30 K |
Metallicity [Fe/H] | −0.34±0.02 dex |
Age | 3.55±0.12 Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Iota Eridani (ι Eri) is a solitary star in the constellation Eridanus. It is visible to the naked eye with an apparent magnitude of 4.11.[2] With an annual parallax shift of 0.02165 arcseconds,[1] it lies at an estimated distance of about 151 light years.
This is an evolved giant star with a stellar classification of K0 III.[4] The measured angular diameter, after correcting for limb darkening, is 2.248±0.014 mas. This star is 3.55 billion years old, sufficient to have exhausted the hydrogen at its core and reached a red clump stage. It is only around 29% more massive than the Sun, but is eleven times larger. It radiates 54.7 times the solar luminosity from its outer atmosphere at an effective temperature of 4,700 K.[6]
References
[edit]- ^ 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.
- ^ a b c d Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
- ^ a b Liu, Y. J.; et al. (2007), "The abundances of nearby red clump giants", Monthly Notices of the Royal Astronomical Society, 382 (2): 553–66, Bibcode:2007MNRAS.382..553L, doi:10.1111/j.1365-2966.2007.11852.x
- ^ a b Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
- ^ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
- ^ a b Gallenne, A.; Pietrzyński, G.; Graczyk, D.; Nardetto, N.; Mérand, A.; Kervella, P.; Gieren, W.; Villanova, S.; Mennickent, R. E.; Pilecki, B. (2018-08-01), "Fundamental properties of red-clump stars from long-baseline H-band interferometry", Astronomy & Astrophysics, 616: A68, arXiv:1806.09572, doi:10.1051/0004-6361/201833341, ISSN 0004-6361
- ^ "iot Eri". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-10-29.
{{cite web}}
: CS1 maint: postscript (link)