HE 1523-0901: Difference between revisions

HE 1523-0901
	; Artist's impression of HE 1523-0901
Observation data; Epoch J2000 Equinox J2000
Constellation	Libra
Right ascension	15h 26m 01.070s
Declination	−09° 11′ 38.89″
Apparent magnitude (V)	11.129
Characteristics
Evolutionary stage	red giant branch
Spectral type	CEMP
B−V color index	+1.057
Astrometry
Radial velocity (Rv)	−162.48±0.34 km/s
Proper motion (μ)	RA: −22.685 mas/yr ; Dec.: −28.204 mas/yr
Parallax (π)	0.3278 ± 0.0197 mas
Distance	9,900 ± 600 ly ; (3,100 ± 200 pc)
Details
Mass	0.80±0.01 M☉
Radius	27 R☉
Luminosity	730 L☉
Surface gravity (log g)	1.29±0.15 cgs
Temperature	4,742±100 K
Metallicity [Fe/H]	−2.65±0.22 dex
Age	13.2 Gyr
Other designations
	HE 1523-0901, TYC 5594-576-1, 2MASS J15260106-0911388
Database references
SIMBAD	data

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HE 1523-0901 is the designation given to a red giant star in the Milky Way galaxy approximately 9,900 light-years from Earth. It is thought to be a second generation, Population II, or metal-poor, star ([Fe/H] = −2.95). The star was found in the sample of bright metal-poor halo stars from the Hamburg/ESO Survey by Anna Frebel and collaborators. The group's research was published in the May 10, 2007 issue of The Astrophysical Journal.^[5]

Age

The star's age, as measured by ESO's Very Large Telescope, is 13.2 billion years. This makes it among the oldest stars^[6] and nearly as old as the estimated age of the universe itself (13.8 billion years as measured by Planck). The measurement uncertainty in the age estimate is 0.7 to 2.7 billion years, depending upon the assumptions made to estimate the uncertainty, although the uncertainty in the relative age of this and other stars using the same method is smaller.^[5] HE 1523-0901 is the first star whose age was determined using the decay of the radioactive elements uranium and thorium in tandem with measurements of several neutron capture elements.^[7] It is believed to have formed directly from the remnants of the first-generation stars that reached the end of their longevity and exploded as supernovae early in the history of known matter.

Designation

The designation "HE 1523-0901" indicates that the star is part of the Hamburg/ESO Survey catalog. A list of astronomical catalogues can be used to find which catalog a star or other object is from based on its prefix. Most objects are listed in several catalogs and will often be known by several different designations.

Observation

HE 1523-0901 is approximately 0.8 solar masses, but the star has expanded until it is some 27 times as large, and has a total luminosity of 730 times that of the Sun. It can be viewed particularly well from the southern hemisphere with the use of a small telescope. It can also be observed from central European latitudes.

Spectroscopic companion

HE 1523-0901 was found to be a spectroscopic binary by a 2015 study.^[8] The companion has a minimum mass about 11 times the mass of Jupiter,^[9] suggesting that it may be a brown dwarf or massive exoplanet. However, the discovery paper suggests that the companion's orbit may be nearly face-on, which would make the true mass much greater than the minimum mass, at about a quarter the mass of the Sun.^[8] Such an object would be a red dwarf star. The orbital inclination and thus true mass is not yet known with certainty.

The HE 1523-0901 planetary system^[9]
Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	≥11+4 −1 $M$ _J	—	303.05±0.25	0.163±0.010	—	—

References

^ ^a ^b ^c ^d ^e ^f ^g ^h Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
^ ^a ^b Beers, Timothy C.; Flynn, Chris; Rossi, Silvia; Sommer-Larsen, Jesper; Wilhelm, Ronald; Marsteller, Brian; Lee, Young Sun; De Lee, Nathan; Krugler, Julie; Deliyannis, Constantine P.; Simmons, Andrew T.; Mills, Elisabeth; Zickgraf, Franz-Josef; Holmberg, Johan; Önehag, Anna; Eriksson, Anders; Terndrup, Donald M.; Salim, Samir; Andersen, Johannes; Nordström, Birgitta; Christlieb, Norbert; Frebel, Anna; Rhee, Jaehyon (2007). "Broadband UBVR_CI_C Photometry of Horizontal-Branch and Metal-poor Candidates from the HK and Hamburg/ESO Surveys. I.". The Astrophysical Journal Supplement Series. 168 (1): 128. arXiv:astro-ph/0610018. Bibcode:2007ApJS..168..128B. doi:10.1086/509324. S2CID 119500060.
^ Placco, Vinicius M.; Beers, Timothy C.; Santucci, Rafael M.; Chanamé, Julio; Sepúlveda, María Paz; Coronado, Johanna; Points, Sean D.; Kaleida, Catherine C.; Rossi, Silvia; Kordopatis, Georges; Lee, Young Sun; Matijevič, Gal; Frebel, Anna; Hansen, Terese T.; Holmbeck, Erika M.; Rasmussen, Kaitlin C.; Roederer, Ian U.; Sakari, Charli M.; Whitten, Devin D. (2018). "Spectroscopic Validation of Low-metallicity Stars from RAVE". The Astronomical Journal. 155 (6): 256. arXiv:1805.00608. Bibcode:2018AJ....155..256P. doi:10.3847/1538-3881/aac20c. S2CID 119460225.
^ ^a ^b ^c ^d Reggiani, Henrique; Ji, Alexander P.; Schlaufman, Kevin C.; Frebel, Anna; Necib, Lina; Nelson, Tyler; Hawkins, Keith; Galarza, Jhon Yana (2022). "The Chemical Composition of Extreme-velocity Stars". The Astronomical Journal. 163 (6): 252. arXiv:2203.16364. Bibcode:2022AJ....163..252R. doi:10.3847/1538-3881/ac62d9. S2CID 247793231.
^ ^a ^b ^c Frebel, A.; et al. (2007). "Discovery of HE 1523–0901, a Strongly r-Process-enhanced Metal-poor Star with Detected Uranium". The Astrophysical Journal. 660 (2): L117. arXiv:astro-ph/0703414. Bibcode:2007ApJ...660L.117F. doi:10.1086/518122. S2CID 17533424.
^ "Nearby Star Is A Galactic Fossil". Science Daily. May 11, 2007. Retrieved 2007-05-10.
^ "A galactic fossil: Star is found to be 13.2 billion years old". PhysOrg. May 10, 2007. Retrieved 2007-05-12.
^ ^a ^b Hansen, T. T.; Andersen, J.; Nordström, B.; Beers, T. C.; Yoon, J.; Buchhave, L. A. (2015), "The role of binaries in the enrichment of the early Galactic halo. I. r-process-enhanced metal-poor stars", Astronomy & Astrophysics, 583: A49, arXiv:1509.05344, Bibcode:2015A&A...583A..49H, doi:10.1051/0004-6361/201526812
^ ^a ^b Schlaufman, Kevin C.; Thompson, Ian B.; Casey, Andrew R. (2018), "An Ultra Metal-poor Star Near the Hydrogen-burning Limit", Astronomy & Astrophysics, 867 (2): 98, arXiv:1811.00549, Bibcode:2018ApJ...867...98S, doi:10.3847/1538-4357/aadd97

External links

"Astronomers discover HE 1523-0901 star: Almost as old as universe". iTWire. Archived from the original on 2007-05-14. Retrieved 2007-05-15.
"Ancient star nearly as old as the universe". NBC News. 11 May 2007. Retrieved 2007-05-14.

[dr3-1] ^ ^a ^b ^c ^d ^e ^f ^g ^h Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.

[ubv-2] Beers, Timothy C.; Flynn, Chris; Rossi, Silvia; Sommer-Larsen, Jesper; Wilhelm, Ronald; Marsteller, Brian; Lee, Young Sun; De Lee, Nathan; Krugler, Julie; Deliyannis, Constantine P.; Simmons, Andrew T.; Mills, Elisabeth; Zickgraf, Franz-Josef; Holmberg, Johan; Önehag, Anna; Eriksson, Anders; Terndrup, Donald M.; Salim, Samir; Andersen, Johannes; Nordström, Birgitta; Christlieb, Norbert; Frebel, Anna; Rhee, Jaehyon (2007). "Broadband UBVR_CI_C Photometry of Horizontal-Branch and Metal-poor Candidates from the HK and Hamburg/ESO Surveys. I.". The Astrophysical Journal Supplement Series. 168 (1): 128. arXiv:astro-ph/0610018. Bibcode:2007ApJS..168..128B. doi:10.1086/509324. S2CID 119500060.

[placco2018-3] Placco, Vinicius M.; Beers, Timothy C.; Santucci, Rafael M.; Chanamé, Julio; Sepúlveda, María Paz; Coronado, Johanna; Points, Sean D.; Kaleida, Catherine C.; Rossi, Silvia; Kordopatis, Georges; Lee, Young Sun; Matijevič, Gal; Frebel, Anna; Hansen, Terese T.; Holmbeck, Erika M.; Rasmussen, Kaitlin C.; Roederer, Ian U.; Sakari, Charli M.; Whitten, Devin D. (2018). "Spectroscopic Validation of Low-metallicity Stars from RAVE". The Astronomical Journal. 155 (6): 256. arXiv:1805.00608. Bibcode:2018AJ....155..256P. doi:10.3847/1538-3881/aac20c. S2CID 119460225.

[reggiani2022-4] Reggiani, Henrique; Ji, Alexander P.; Schlaufman, Kevin C.; Frebel, Anna; Necib, Lina; Nelson, Tyler; Hawkins, Keith; Galarza, Jhon Yana (2022). "The Chemical Composition of Extreme-velocity Stars". The Astronomical Journal. 163 (6): 252. arXiv:2203.16364. Bibcode:2022AJ....163..252R. doi:10.3847/1538-3881/ac62d9. S2CID 247793231.

[frebel-5] Frebel, A.; et al. (2007). "Discovery of HE 1523–0901, a Strongly r-Process-enhanced Metal-poor Star with Detected Uranium". The Astrophysical Journal. 660 (2): L117. arXiv:astro-ph/0703414. Bibcode:2007ApJ...660L.117F. doi:10.1086/518122. S2CID 17533424.

[6] "Nearby Star Is A Galactic Fossil". Science Daily. May 11, 2007. Retrieved 2007-05-10.

[7] "A galactic fossil: Star is found to be 13.2 billion years old". PhysOrg. May 10, 2007. Retrieved 2007-05-12.

[Hansen2015-8] Hansen, T. T.; Andersen, J.; Nordström, B.; Beers, T. C.; Yoon, J.; Buchhave, L. A. (2015), "The role of binaries in the enrichment of the early Galactic halo. I. r-process-enhanced metal-poor stars", Astronomy & Astrophysics, 583: A49, arXiv:1509.05344, Bibcode:2015A&A...583A..49H, doi:10.1051/0004-6361/201526812

[Schlaufman2018-9] Schlaufman, Kevin C.; Thompson, Ian B.; Casey, Andrew R. (2018), "An Ultra Metal-poor Star Near the Hydrogen-burning Limit", Astronomy & Astrophysics, 867 (2): 98, arXiv:1811.00549, Bibcode:2018ApJ...867...98S, doi:10.3847/1538-4357/aadd97

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[2]

[3]

[4]

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@@ Line 6: / Line 6: @@
 }}
 {{Starbox observe
- | Age= [[Age=13.2 Billion Years!]]
  | epoch=[[J2000]]
  | constell=[[Libra (constellation)|Libra]]
  | ra={{RA|15|26|01.070}}<ref name=dr3/>
- | dec={{DEC|-9|11|38.89}}<ref name=dr3/>
+ | dec={{DEC|-09|11|38.89}}<ref name=dr3/>
+ | appmag_v=11.129<ref name=ubv/>
- | appmag_v=11.129<ref name=ubv>{{cite journal |bibcode=2007ApJS..168..128B |title=Broadband UBVR<SUB>C</SUB>I<SUB>C</SUB> Photometry of Horizontal-Branch and Metal-poor Candidates from the HK and Hamburg/ESO Surveys. I. |last1=Beers |first1=Timothy C. |last2=Flynn |first2=Chris |last3=Rossi |first3=Silvia |last4=Sommer-Larsen |first4=Jesper |last5=Wilhelm |first5=Ronald |last6=Marsteller |first6=Brian |last7=Lee |first7=Young Sun |last8=De Lee |first8=Nathan |last9=Krugler |first9=Julie |last10=Deliyannis |first10=Constantine P. |last11=Simmons |first11=Andrew T. |last12=Mills |first12=Elisabeth |last13=Zickgraf |first13=Franz-Josef |last14=Holmberg |first14=Johan |last15=Önehag |first15=Anna |last16=Eriksson |first16=Anders |last17=Terndrup |first17=Donald M. |last18=Salim |first18=Samir |last19=Andersen |first19=Johannes |last20=Nordström |first20=Birgitta |last21=Christlieb |first21=Norbert |last22=Frebel |first22=Anna |last23=Rhee |first23=Jaehyon |journal=The Astrophysical Journal Supplement Series |year=2007 |volume=168 |issue=1 |page=128 |doi=10.1086/509324 |arxiv=astro-ph/0610018 |s2cid=119500060 }}</ref>
 }}
 {{Starbox character
  | type = [[red giant branch]]<ref name=dr3/>
+ | class = [[CEMP star|CEMP]]<ref name=placco2018/>
- | class = [[CEMP star|CEMP]]<ref name=placco2018>{{cite journal |bibcode=2018AJ....155..256P |title=Spectroscopic Validation of Low-metallicity Stars from RAVE |last1=Placco |first1=Vinicius M. |last2=Beers |first2=Timothy C. |last3=Santucci |first3=Rafael M. |last4=Chanamé |first4=Julio |last5=Sepúlveda |first5=María Paz |last6=Coronado |first6=Johanna |last7=Points |first7=Sean D. |last8=Kaleida |first8=Catherine C. |last9=Rossi |first9=Silvia |last10=Kordopatis |first10=Georges |last11=Lee |first11=Young Sun |last12=Matijevič |first12=Gal |last13=Frebel |first13=Anna |last14=Hansen |first14=Terese T. |last15=Holmbeck |first15=Erika M. |last16=Rasmussen |first16=Kaitlin C. |last17=Roederer |first17=Ian U. |last18=Sakari |first18=Charli M. |last19=Whitten |first19=Devin D. |journal=The Astronomical Journal |year=2018 |volume=155 |issue=6 |page=256 |doi=10.3847/1538-3881/aac20c |arxiv=1805.00608 |s2cid=119460225 |doi-access=free }}</ref>
  | b-v = +1.057<ref name=ubv/>
 }}
 {{Starbox astrometry
- | prop_mo_ra = −22.685<ref name=dr3/>
+ | radial_v = {{val|-162.48|0.34}}<ref name=dr3/>
+ | prop_mo_ra = −22.685
- | prop_mo_dec = −28.204<ref name=dr3/>
+ | prop_mo_dec = −28.204
+ | pm_footnote = <ref name=dr3/>
  | parallax = 0.3278
- | p_error = 0.0140
+ | p_error = 0.0197
- | parallax_footnote = <ref name=dr3>{{cite Gaia DR3|6317828550897175936}}</ref>
+ | parallax_footnote = <ref name=dr3/>
- | dist_ly=
- | dist_pc=
  | absmag_v =
 }}
 {{Starbox detail
+ | mass = {{val|0.80|0.01}}<ref name=reggiani2022/>
- | mass = 0.80<ref name=reggiani2022>{{cite journal |bibcode=2022AJ....163..252R |title=The Chemical Composition of Extreme-velocity Stars |last1=Reggiani |first1=Henrique |last2=Ji |first2=Alexander P. |last3=Schlaufman |first3=Kevin C. |last4=Frebel |first4=Anna |last5=Necib |first5=Lina |last6=Nelson |first6=Tyler |last7=Hawkins |first7=Keith |last8=Galarza |first8=Jhon Yana |journal=The Astronomical Journal |year=2022 |volume=163 |issue=6 |page=252 |doi=10.3847/1538-3881/ac62d9 |arxiv=2203.16364 |s2cid=247793231 |doi-access=free }}</ref>
  | radius = 27<ref name=dr3/>
  | luminosity = 730<ref name=dr3/>
- | temperature = 4,742<ref name=reggiani2022/>
+ | gravity = {{val|1.29|0.15}}<ref name=reggiani2022/>
- | metal_fe = −2.65<ref name=reggiani2022/>
+ | temperature = {{val|4742|100|fmt=commas}}<ref name=reggiani2022/>
- | gravity = 1.29<ref name=reggiani2022/>
+ | metal_fe = {{val|−2.65|0.22}}<ref name=reggiani2022/>
  | age_gyr = 13.2<ref name="frebel"/>
+}}
+{{Starbox catalog
+ | names = [[Hamburg/ESO Survey|HE]] 1523-0901, {{odlist | 2MASS=J15260106-0911388 | TYC=5594-576-1}}
 }}
 {{Starbox reference
@@ Line 41: / Line 43: @@
 }}
 {{Starbox end}}
-'''HE 1523-0901''' is the designation given to a [[red giant]] [[star]] in the [[Milky Way]] galaxy approximately 9,900 [[light year]]s from [[Earth]]. It is thought to be a [[Stellar population|second generation]], [[Population II]], or metal-poor, star ([Fe/H]&nbsp;=&nbsp;−2.95). The star was found in the sample of bright metal-poor [[halo star]]s from the [[Hamburg/ESO Survey]] by [[Anna Frebel]] and collaborators. The group's research was published in the May 10, 2007 issue of ''[[The Astrophysical Journal]]''.<ref name="frebel">
+'''HE 1523-0901''' is the designation given to a [[red giant]] [[star]] in the [[Milky Way]] galaxy approximately 9,900 [[light-year]]s from [[Earth]]. It is thought to be a [[Stellar population|second generation]], [[Population II]], or metal-poor, star ([Fe/H]&nbsp;=&nbsp;−2.95). The star was found in the sample of bright metal-poor [[halo star]]s from the [[Hamburg/ESO Survey]] by [[Anna Frebel]] and collaborators. The group's research was published in the May 10, 2007 issue of ''[[The Astrophysical Journal]]''.<ref name="frebel"/>
-{{cite journal
- |last1= Frebel|first1=A.
- |display-authors=etal
- |date=2007
- |journal=[[The Astrophysical Journal]]
- |volume=660 |issue=2 |page=L117
- |title=Discovery of HE 1523–0901, a Strongly r-Process-enhanced Metal-poor Star with Detected Uranium
- |arxiv=astro-ph/0703414
- |bibcode=2007ApJ...660L.117F
- |doi=10.1086/518122
- |s2cid=17533424
- }}</ref>
 ==Age==
@@ Line 64: / Line 55: @@
 HE 1523-0901 is approximately 0.8 [[solar mass]]es, but the star has expanded until it is some 27 [[solar radius|times as large]], and has a [[bolometric luminosity|total luminosity]] of 730 times [[solar luminosity|that of the Sun]]. It can be viewed particularly well from the southern hemisphere with the use of a small telescope. It can also be observed from central European latitudes.
+==Spectroscopic companion==
-==Planetary system==
+HE 1523-0901 was found to be a [[spectroscopic binary]] by a 2015 study.<ref name=Hansen2015/> The companion has a [[minimum mass]] about 11 times the [[Jupiter mass|mass of Jupiter]],<ref name=Schlaufman2018/> suggesting that it may be a [[brown dwarf]] or massive [[exoplanet]]. However, the discovery paper suggests that the companion's orbit may be nearly face-on, which would make the true mass much greater than the minimum mass, at about a quarter the [[Solar mass|mass of the Sun]].<ref name=Hansen2015/> Such an object would be a [[red dwarf]] star. The [[orbital inclination]] and thus true mass is not yet known with certainty.
-A companion was first found in 2015 from radial velocity observations of HE 1523-0901. First thought to be a red dwarf,<ref name=Hansen2015>{{citation|arxiv=1509.05344|year=2015|title=The role of binaries in the enrichment of the early Galactic halo. I. r-process-enhanced metal-poor stars|doi=10.1051/0004-6361/201526812 |last1=Hansen |first1=T. T. |last2=Andersen |first2=J. |last3=Nordström |first3=B. |last4=Beers |first4=T. C. |last5=Yoon |first5=J. |last6=Buchhave |first6=L. A. |journal=Astronomy & Astrophysics |volume=583 |pages=A49|bibcode=2015A&A...583A..49H }}</ref> it was later found out to be a massive planet or brown dwarf in 2018.<ref name=Schlaufman2018>{{citation|arxiv=1811.00549|year=2018|title=An Ultra Metal-poor Star Near the Hydrogen-burning Limit|doi=10.3847/1538-4357/aadd97 |last1=Schlaufman |first1=Kevin C. |last2=Thompson |first2=Ian B. |last3=Casey |first3=Andrew R. |journal=Astronomy & Astrophysics |volume=867 |issue=2 |pages=98|doi-access=free |bibcode=2018ApJ...867...98S }}</ref>
 {{OrbitboxPlanet begin
 | name = HE 1523-0901
@@ Line 73: / Line 65: @@
 {{OrbitboxPlanet
 | exoplanet = b
-| mass = 11{{±|4|1}}
+| mass = {{val|11|4|1|p=≥}}
 | radius =
 | semimajor =
@@ Line 85: / Line 77: @@
 *[[HD 140283]]
 *[[Sneden's Star]]
 ==References==
-{{Reflist}}
+{{Reflist|refs=
+<ref name=dr3>{{cite Gaia DR3|6317828550897175936}}</ref>
+<ref name=ubv>{{cite journal |bibcode=2007ApJS..168..128B |title=Broadband UBVR<SUB>C</SUB>I<SUB>C</SUB> Photometry of Horizontal-Branch and Metal-poor Candidates from the HK and Hamburg/ESO Surveys. I. |last1=Beers |first1=Timothy C. |last2=Flynn |first2=Chris |last3=Rossi |first3=Silvia |last4=Sommer-Larsen |first4=Jesper |last5=Wilhelm |first5=Ronald |last6=Marsteller |first6=Brian |last7=Lee |first7=Young Sun |last8=De Lee |first8=Nathan |last9=Krugler |first9=Julie |last10=Deliyannis |first10=Constantine P. |last11=Simmons |first11=Andrew T. |last12=Mills |first12=Elisabeth |last13=Zickgraf |first13=Franz-Josef |last14=Holmberg |first14=Johan |last15=Önehag |first15=Anna |last16=Eriksson |first16=Anders |last17=Terndrup |first17=Donald M. |last18=Salim |first18=Samir |last19=Andersen |first19=Johannes |last20=Nordström |first20=Birgitta |last21=Christlieb |first21=Norbert |last22=Frebel |first22=Anna |last23=Rhee |first23=Jaehyon |journal=The Astrophysical Journal Supplement Series |year=2007 |volume=168 |issue=1 |page=128 |doi=10.1086/509324 |arxiv=astro-ph/0610018 |s2cid=119500060 }}</ref>
+<ref name="frebel">
+{{cite journal
+ |last1= Frebel|first1=A.
+ |display-authors=etal
+ |date=2007
+ |journal=[[The Astrophysical Journal]]
+ |volume=660 |issue=2 |page=L117
+ |title=Discovery of HE 1523–0901, a Strongly r-Process-enhanced Metal-poor Star with Detected Uranium
+ |arxiv=astro-ph/0703414
+ |bibcode=2007ApJ...660L.117F
+ |doi=10.1086/518122
+ |s2cid=17533424
+ }}</ref>
+<ref name=Hansen2015>{{citation|arxiv=1509.05344|year=2015|title=The role of binaries in the enrichment of the early Galactic halo. I. r-process-enhanced metal-poor stars|doi=10.1051/0004-6361/201526812 |last1=Hansen |first1=T. T. |last2=Andersen |first2=J. |last3=Nordström |first3=B. |last4=Beers |first4=T. C. |last5=Yoon |first5=J. |last6=Buchhave |first6=L. A. |journal=Astronomy & Astrophysics |volume=583 |pages=A49|bibcode=2015A&A...583A..49H }}</ref>
+<ref name=placco2018>{{cite journal |bibcode=2018AJ....155..256P |title=Spectroscopic Validation of Low-metallicity Stars from RAVE |last1=Placco |first1=Vinicius M. |last2=Beers |first2=Timothy C. |last3=Santucci |first3=Rafael M. |last4=Chanamé |first4=Julio |last5=Sepúlveda |first5=María Paz |last6=Coronado |first6=Johanna |last7=Points |first7=Sean D. |last8=Kaleida |first8=Catherine C. |last9=Rossi |first9=Silvia |last10=Kordopatis |first10=Georges |last11=Lee |first11=Young Sun |last12=Matijevič |first12=Gal |last13=Frebel |first13=Anna |last14=Hansen |first14=Terese T. |last15=Holmbeck |first15=Erika M. |last16=Rasmussen |first16=Kaitlin C. |last17=Roederer |first17=Ian U. |last18=Sakari |first18=Charli M. |last19=Whitten |first19=Devin D. |journal=The Astronomical Journal |year=2018 |volume=155 |issue=6 |page=256 |doi=10.3847/1538-3881/aac20c |arxiv=1805.00608 |s2cid=119460225 |doi-access=free }}</ref>
+<ref name=Schlaufman2018>{{citation|arxiv=1811.00549|year=2018|title=An Ultra Metal-poor Star Near the Hydrogen-burning Limit|doi=10.3847/1538-4357/aadd97 |last1=Schlaufman |first1=Kevin C. |last2=Thompson |first2=Ian B. |last3=Casey |first3=Andrew R. |journal=Astronomy & Astrophysics |volume=867 |issue=2 |pages=98|doi-access=free |bibcode=2018ApJ...867...98S }}</ref>
+<ref name=reggiani2022>{{cite journal |bibcode=2022AJ....163..252R |title=The Chemical Composition of Extreme-velocity Stars |last1=Reggiani |first1=Henrique |last2=Ji |first2=Alexander P. |last3=Schlaufman |first3=Kevin C. |last4=Frebel |first4=Anna |last5=Necib |first5=Lina |last6=Nelson |first6=Tyler |last7=Hawkins |first7=Keith |last8=Galarza |first8=Jhon Yana |journal=The Astronomical Journal |year=2022 |volume=163 |issue=6 |page=252 |doi=10.3847/1538-3881/ac62d9 |arxiv=2203.16364 |s2cid=247793231 |doi-access=free }}</ref>
+}}
 == External links ==
 *{{cite web|url=http://www.itwire.com.au/content/view/12098/1066/|title=Astronomers discover HE 1523-0901 star: Almost as old as universe|publisher=iTWire|access-date=2007-05-15|archive-url=https://web.archive.org/web/20070514034340/http://www.itwire.com.au/content/view/12098/1066/|archive-date=2007-05-14|url-status=dead}}
 *{{cite web|url=http://www.nbcnews.com/id/18612697|title=Ancient star nearly as old as the universe|date=11 May 2007 |publisher=NBC News|access-date=2007-05-14}}
 {{Sky|15|26|01.2|-|09|11|38|7500}}

Observation data Epoch J2000 Equinox J2000
Artist's impression of HE 1523-0901
Constellation	Libra
Right ascension	15^h 26^m 01.070^s^[1]
Declination	−09° 11′ 38.89″^[1]
Apparent magnitude (V)	11.129^[2]
Characteristics
Evolutionary stage	red giant branch^[1]
Spectral type	CEMP^[3]
B−V color index	+1.057^[2]
Astrometry

Radial velocity (R_v)	−162.48±0.34^[1] km/s
Proper motion (μ)	RA: −22.685 mas/yr^[1] Dec.: −28.204 mas/yr^[1]
Parallax (π)	0.3278 ± 0.0197 mas^[1]
Distance	9,900 ± 600 ly (3,100 ± 200 pc)

Details

Mass	0.80±0.01^[4] `M`_☉
Radius	27^[1] `R`_☉
Luminosity	730^[1] `L`_☉
Surface gravity (log g)	1.29±0.15^[4] cgs
Temperature	4,742±100^[4] K
Metallicity [Fe/H]	−2.65±0.22^[4] dex
Age	13.2^[5] Gyr

Other designations
HE 1523-0901, TYC 5594-576-1, 2MASS J15260106-0911388
Database references
SIMBAD	data