View source for Astronomy:HD 39901

{{Short description|Star in the constellation Columba}}
{{Starbox begin
 | name = HD 39901
}}
{{Starbox observe
 | epoch       = [[Astronomy:J2000.0|J2000.0]] ([[Astronomy:International Celestial Reference System|ICRS]])
 | constell    = [[Astronomy:Columba (constellation)|Columba]]
 | ra          = {{RA|05|53|22.85088}}<ref name = GaiaDR3/>
 | dec         = {{DEC|-42|55|16.7853}}<ref name = GaiaDR3/>
 | appmag_v    = 6.54{{±|0.01}}<ref name = Tycho2000/>
}}
{{Starbox character
 | type        = 
 | class       = K3 III<ref name = Houk1978/>
 | b-v         = +1.37<ref name = Corben1971/>
 | u-b         = 
 | variable    = 
}}
{{Starbox astrometry
 | radial_v    = −10.3{{±|0.4}}<ref name = Gontcharov2006/>
 | prop_mo_ra  = +5.109
 | prop_mo_dec = +11.405
 | pm_footnote = <ref name = GaiaDR3/>
 | parallax    = 5.1076
 | p_error     = 0.0152
 | parallax_footnote = <ref name = GaiaDR3/>
 | absmag_v    = −0.03<ref name=Anderson2012/>
}}
{{Starbox detail
 | mass        = 1.27<ref name = Anders2022/>
 | radius      = 21.9<ref name = Kervella2021/>
 | luminosity  = {{Val|143|1}}<ref name=GaiaDR2/>
 | temperature = 4,373{{±|122}}<ref name = Stassun2019/>
 | gravity     = 1.87<ref name = Anders2022/>
 | metal_fe    = +0.08<ref name = Eggen1989/>
 | rotational_velocity = <1.6<ref name = DeMed2014/>
 | age_gyr     = 
}}
{{Starbox catalog
 | names = {{odlist | CD=−42°2205 | HD=39901 | HIP=27835 | HR=2069 | SAO=217599 | GC=7431 | CPD=−42°769 | Gould=59 G. Columbae<ref name = Gould1879/> }}<ref name=SIMBAD/>
}}
{{Starbox reference
 | Simbad = HD+39901
}}
{{Starbox end}}

'''HD 39901''' is an orange hued [[Astronomy:Star|star]] located in the [[Astronomy:Constellation|constellation]] [[Astronomy:Columba (constellation)|Columba]]. It is also called '''HR 2069''', which is the star's Bright Star Catalog designation. Eggen (1989) lists it as a member of the old disk population.<ref name = Eggen1989/>

Despite the HR designation, the object has an [[Astronomy:Apparent magnitude|apparent magnitude]] of 6.54,<ref name = Tycho2000/> slightly past the limit for the [[Astronomy:Naked eye|naked eye]] visibility. As a result, it is barely visible to the unaided eye in the best conditions. [[Astronomy:Parallax|Parallax]] measurements from the Gaia spacecraft place the object 639 [[Light year|light year]]s away.<ref name = GaiaDR3/> It is approaching the [[Astronomy:Solar System|Solar System]] with a heliocentric [[Astronomy:Radial velocity|radial velocity]] of {{val|−10.3|ul=km/s}}.<ref name = Gontcharov2006/>  At that distance, HD 39901's brightness is diminished by 0.33 [[Astronomy:Magnitude|magnitude]]s due to interstellar dust.<ref name = Gontcharov2017/> It has an [[Astronomy:Absolute magnitude|absolute magnitude]] of −0.03.<ref name=Anderson2012/>

This is an evolved red giant star with a [[Astronomy:Stellar classification|stellar classification]] of K3 III.<ref name = Houk1978/> It has a comparable [[Physics:Mass|mass]] to the [[Astronomy:Sun|Sun]]<ref name = Anders2022/> but has expanded to 21.9 times the latter's [[Astronomy:Solar radius|girth]].<ref name = Kervella2021/> It radiates 143 times the luminosity of the Sun<ref name=GaiaDR2/> from its [[Astronomy:Photosphere|photosphere]] at an [[Astronomy:Effective temperature|effective temperature]] of 4,373 [[Kelvin|K]].<ref name = Stassun2019/> HD 39901 is slightly enriched in heavy elements with a [[Astronomy:Metallicity|metallicity]] 120% that of the Sun's.<ref name = Eggen1989/> Like most giants, it spins slowly, having a projected rotational velocity lower than {{val|1.6|ul=km/s}}.<ref name = DeMed2014/>

==References==
{{reflist|refs=

<ref name=SIMBAD>{{cite simbad | title=HD 39901 | accessdate=2011-12-20}}</ref>

<ref name = GaiaDR3>{{Cite DR3|4803527265350781056}}</ref>

<ref name=GaiaDR2>{{Cite Gaia DR2|4642472794978268800}}</ref>

<ref name = Tycho2000>{{cite journal | last1 = Høg | first1 = E. | last2 = Fabricius | first2 = C. | last3 = Makarov | first3 = V. V. | last4 = Urban | first4 = S. | last5 = Corbin | first5 = T. | last6 = Wycoff | first6 = G. | last7 = Bastian | first7 = U. | last8 = Schwekendiek | first8 = P. | last9 = Wicenec | first9 = A. | title = The Tycho-2 catalogue of the 2.5 million brightest stars |journal=Astronomy and Astrophysics | date = March 2000 | volume = 355 | pages = L27–L30 | bibcode = 2000A&A...355L..27H | issn = 0004-6361}}</ref>

<ref name = Corben1971>{{cite journal |last1=Corben |first1=P. M. |title=Photoelectric Magnitudes and Colours for Bright Southern Stars |journal=Monthly Notes of the Astronomical Society of South Africa |date=April 1971 |volume=30 |issue=4 |pages=37 |issn=0024-8266 |bibcode=1971MNSSA..30...37C}}</ref>

<ref name = Anderson2012>{{cite journal | last1 = Anderson | first1 = E. | last2 = Francis | first2 = Ch. | title = XHIP: An extended hipparcos compilation | journal = Astronomy Letters | date = May 2012 | volume = 38 | issue = 5 | pages = 331–346 | issn = 1063-7737 | eissn = 1562-6873 | doi = 10.1134/S1063773712050015 | bibcode = 2012AstL...38..331A | arxiv = 1108.4971| s2cid = 119257644 }}</ref>

<ref name = Houk1978>{{cite book |last1=Houk |first1=Nancy |title=Michigan catalogue of two-dimensional spectral types for the HD stars Volume II: Declinations −52° to −41° |year=1978 |bibcode=1978mcts.book.....H }}</ref>

<ref name = Gontcharov2006>{{cite journal | last1 = Gontcharov | first1 = G. A. | title = Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system | journal = Astronomy Letters | date = November 2006 | volume = 32 | issue = 11 | pages = 759–771 | issn = 1063-7737 | eissn = 1562-6873 | doi = 10.1134/S1063773706110065 | pmid = | bibcode = 2006AstL...32..759G | arxiv = 1606.08053 | s2cid = 119231169 }}</ref>

<ref name = Anders2022>{{cite journal | display-authors = 1 | last1 = Anders | first1 = F. | last2 = Khalatyan | first2 = A. | last3 = Queiroz | first3 = A. B. A. | last4 = Chiappini | first4 = C. | last5 = Ardèvol | first5 = J. | last6 = Casamiquela | first6 = L. | last7 = Figueras | first7 = F. | last8 = Jiménez-Arranz | first8 = Ó. | last9 = Jordi | first9 = C. | last10 = Monguió | first10 = M. | last11 = Romero-Gómez | first11 = M. | last12 = Altamirano | first12 = D. | last13 = Antoja | first13 = T. | last14 = Assaad | first14 = R. | last15 = Cantat-Gaudin | first15 = T. | last16 = Castro-Ginard | first16 = A. | last17 = Enke | first17 = H. | last18 = Girardi | first18 = L. | last19 = Guiglion | first19 = G. | last20 = Khan | first20 = S. | last21 = Luri | first21 = X. | last22 = Miglio | first22 = A. | last23 = Minchev | first23 = I. | last24 = Ramos | first24 = P. | last25 = Santiago | first25 = B. X. | last26 = Steinmetz | first26 = M. | title = Photo-astrometric distances, extinctions, and astrophysical parameters for <i>Gaia</i> EDR3 stars brighter than <i>G</i> = 18.5 | journal = Astronomy & Astrophysics | date = February 2022 | volume = 658 | page = A91 | issn = 0004-6361 | eissn = 1432-0746 | doi = 10.1051/0004-6361/202142369 | bibcode = 2022A&A...658A..91A | arxiv = 2111.01860 | doi-access = free }}</ref>

<ref name = DeMed2014>{{cite journal | last1 = De Medeiros | first1 = J. R. | last2 = Alves | first2 = S. | last3 = Udry | first3 = S. | last4 = Andersen | first4 = J. | last5 = Nordström | first5 = B. | last6 = Mayor | first6 = M. | title = A catalog of rotational and radial velocities for evolved stars | journal = Astronomy & Astrophysics | date = January 2014 | volume = 561 | page = A126 | issn = 0004-6361 | eissn = 1432-0746 | doi = 10.1051/0004-6361/201220762 | bibcode = 2014A&A...561A.126D | arxiv = 1312.3474 | doi-access = free}}</ref>

<ref name = Stassun2019>{{cite journal | display-authors = 1 | last1 = Stassun | first1 = Keivan G. | last2 = Oelkers | first2 = Ryan J. | last3 = Paegert | first3 = Martin | last4 = Torres | first4 = Guillermo | last5 = Pepper | first5 = Joshua | last6 = Lee | first6 = Nathan De | last7 = Collins | first7 = Kevin | last8 = Latham | first8 = David W. | last9 = Muirhead | first9 = Philip S. | last10 = Chittidi | first10 = Jay | last11 = Rojas-Ayala | first11 = Bárbara | last12 = Fleming | first12 = Scott W. | last13 = Rose | first13 = Mark E. | last14 = Tenenbaum | first14 = Peter | last15 = Ting | first15 = Eric B. | last16 = Kane | first16 = Stephen R. | last17 = Barclay | first17 = Thomas | last18 = Bean | first18 = Jacob L. | last19 = Brassuer | first19 = C. E. | last20 = Charbonneau | first20 = David | last21 = Ge | first21 = Jian | last22 = Lissauer | first22 = Jack J. | last23 = Mann | first23 = Andrew W. | last24 = McLean | first24 = Brian | last25 = Mullally | first25 = Susan | last26 = Narita | first26 = Norio | last27 = Plavchan | first27 = Peter | last28 = Ricker | first28 = George R. | last29 = Sasselov | first29 = Dimitar | last30 = Seager | first30 = S. | last31 = Sharma | first31 = Sanjib | last32 = Shiao | first32 = Bernie | last33 = Sozzetti | first33 = Alessandro | last34 = Stello | first34 = Dennis | last35 = Vanderspek | first35 = Roland | last36 = Wallace | first36 = Geoff | last37 = Winn | first37 = Joshua N. | title = The Revised ''TESS'' Input Catalog and Candidate Target List | journal = The Astronomical Journal | date = 9 September 2019 | volume = 158 | issue = 4 | page = 138 | eissn = 1538-3881 | doi = 10.3847/1538-3881/ab3467 | bibcode = 2019AJ....158..138S | arxiv = 1905.10694 | s2cid = 166227927 | hdl = 1721.1/124721 | hdl-access = free | doi-access = free}}</ref>

<ref name = Kervella2021>{{cite journal | last1 = Kervella | first1 = Pierre | last2 = Arenou | first2 = Frédéric | last3 = Thévenin | first3 = Frédéric | title = Stellar and substellar companions from ''Gaia'' EDR3 | journal = Astronomy & Astrophysics | date = 20 December 2021 | volume = 657 | page = A7 | issn = 0004-6361 | eissn = 1432-0746 | doi = 10.1051/0004-6361/202142146 | bibcode = 2022A&A...657A...7K | arxiv = 2109.10912 | doi-access = free}}</ref>

<ref name = Eggen1989>{{cite journal | last1 = Eggen | first1 = Olin J. | title = Large and kinematically unbiased samples of G- and K-type stars. IV - Evolved stars of the old disk population | journal = Publications of the Astronomical Society of the Pacific | date = April 1989 | volume = 101 | page = 366 | issn = 0004-6280 | eissn = 1538-3873 | doi = 10.1086/132442 | bibcode = 1989PASP..101..366E | doi-access = free}}</ref>

<ref name = Gould1879>{{cite journal | last = Gould | first = Benjamin Apthorp | title = Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas | journal = Resultados del Observatorio Nacional Argentino | volume = 1 | bibcode = 1879RNAO....1.....G | year = 1878}}</ref>

<ref name = Gontcharov2017>{{cite journal | last1 = Gontcharov | first1 = George A. | last2 = Mosenkov | first2 = Aleksandr V. | title = Verifying reddening and extinction for Gaia DR1 TGAS main sequence stars | journal = Monthly Notices of the Royal Astronomical Society | date = 28 September 2017 | volume = 472 | issue = 4 | pages = 3805–3820 | issn = 0035-8711 | eissn = 1365-2966 | doi = 10.1093/mnras/stx2219 | bibcode = 2017MNRAS.472.3805G | arxiv = 1709.01160 | doi-access = free}}</ref>

}}
{{Stars of Columba}}

{{DEFAULTSORT:HD 39901}}
[[Category:K-type giants]]
[[Category:Columba (constellation)]]
[[Category:Durchmusterung objects]]
[[Category:Henry Draper Catalogue objects|039901]]
[[Category:Hipparcos objects|027835]]
[[Category:Bright Star Catalogue objects|2069]]

{{Sourceattribution|HD 39901}}