# HD 100673

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Star in the constellation Centaurus

This article is about A Centauri; not to be confused with [α Centauri](/source/Alpha_Centauri), [a Centauri](/source/HD_125823), or [Centaurus A](/source/Centaurus_A).

HD 100673 Location of A Centauri (circled) Observation data Epoch J2000.0 Equinox J2000.0 Constellation Centaurus[1] Right ascension 11h 34m 45.66s[2] Declination −54° 15′ 50.7″[2] Apparent magnitude (V) +4.62[1] Characteristics Evolutionary stage Main sequence[3] Spectral type B9V[4] U−B color index −0.21[5] B−V color index −0.08[5] Astrometry Radial velocity (Rv) +5.7±2.2[1] km/s Proper motion (μ) RA: −56.17±0.18[2] mas/yr Dec.: 16.19±0.20[2] mas/yr Parallax (π) 7.65±0.22 mas[2] Distance 430 ± 10 ly (131 ± 4 pc) Absolute magnitude (MV) −0.96[1] Details Mass 3.58±0.05[3] M☉ Radius 4.7[6] R☉ Luminosity 306[3] L☉ Surface gravity (log g) 3.54[6] cgs Temperature 10,600[3] K Metallicity [Fe/H] 0.50[7] dex Rotation 0.733[8] days Rotational velocity (v sin i) 160[3] km/s Age 238[9] Myr Other designations A Cen, CPD−53°4637, FK5 2926, GC 15877, HD 100673, HIP 56480, HR 4460, SAO 239189[10] Database references SIMBAD data

**HD 100673**, also known as **A Centauri** is a single[11] [star](/source/Star) in the [southern](/source/Southern_celestial_hemisphere) [constellation](/source/Constellation) of [Centaurus](/source/Centaurus). It is blue-white in hue and is faintly visible to the naked eye with an [apparent visual magnitude](/source/Apparent_visual_magnitude) of +4.62.[1] The star is located at a distance of approximately 430 [light-years](/source/Light-year) from the [Sun](/source/Sun) based on [stellar parallax](/source/Stellar_parallax).[2] It appears to be drifting further away with a [radial velocity](/source/Radial_velocity) of around +6 km/s.[1]

This is a rapidly rotating [Be star](/source/Be_star), showing an [emission-line](/source/Emission-line) [spectrum](/source/Stellar_spectrum) on top of the normal [absorption](/source/Spectral_line) spectrum of the star, due to a [circumstellar disk](/source/Circumstellar_disk) of ejected matter. It doesn't show any absorption lines from the disk.[12] It is a [B-type main-sequence star](/source/B-type_main-sequence_star) with a [stellar classification](/source/Stellar_classification) of B9V.[4]

## References

1. ^ [***a***](#cite_ref-Anderson2012_1-0) [***b***](#cite_ref-Anderson2012_1-1) [***c***](#cite_ref-Anderson2012_1-2) [***d***](#cite_ref-Anderson2012_1-3) [***e***](#cite_ref-Anderson2012_1-4) [***f***](#cite_ref-Anderson2012_1-5) Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". *Astronomy Letters*. **38** (5): 331. [arXiv](/source/ArXiv_(identifier)):[1108.4971](https://arxiv.org/abs/1108.4971). [Bibcode](/source/Bibcode_(identifier)):[2012AstL...38..331A](https://ui.adsabs.harvard.edu/abs/2012AstL...38..331A). [doi](/source/Doi_(identifier)):[10.1134/S1063773712050015](https://doi.org/10.1134%2FS1063773712050015). [S2CID](/source/S2CID_(identifier)) [119257644](https://api.semanticscholar.org/CorpusID:119257644).

1. ^ [***a***](#cite_ref-van_Leeuwen2007_2-0) [***b***](#cite_ref-van_Leeuwen2007_2-1) [***c***](#cite_ref-van_Leeuwen2007_2-2) [***d***](#cite_ref-van_Leeuwen2007_2-3) [***e***](#cite_ref-van_Leeuwen2007_2-4) [***f***](#cite_ref-van_Leeuwen2007_2-5) van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". *Astronomy and Astrophysics*. **474** (2): 653–664. [arXiv](/source/ArXiv_(identifier)):[0708.1752](https://arxiv.org/abs/0708.1752). [Bibcode](/source/Bibcode_(identifier)):[2007A&A...474..653V](https://ui.adsabs.harvard.edu/abs/2007A&A...474..653V). [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20078357](https://doi.org/10.1051%2F0004-6361%3A20078357). [S2CID](/source/S2CID_(identifier)) [18759600](https://api.semanticscholar.org/CorpusID:18759600). [Vizier catalog entry](http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I/311/hip2&recno=56297)

1. ^ [***a***](#cite_ref-Zorec2012_3-0) [***b***](#cite_ref-Zorec2012_3-1) [***c***](#cite_ref-Zorec2012_3-2) [***d***](#cite_ref-Zorec2012_3-3) [***e***](#cite_ref-Zorec2012_3-4) Zorec, J.; Royer, F. (January 2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". *Astronomy & Astrophysics*. **537**: A120. [arXiv](/source/ArXiv_(identifier)):[1201.2052](https://arxiv.org/abs/1201.2052). [Bibcode](/source/Bibcode_(identifier)):[2012A&A...537A.120Z](https://ui.adsabs.harvard.edu/abs/2012A&A...537A.120Z). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/201117691](https://doi.org/10.1051%2F0004-6361%2F201117691). [S2CID](/source/S2CID_(identifier)) [55586789](https://api.semanticscholar.org/CorpusID:55586789).

1. ^ [***a***](#cite_ref-Houk1979_4-0) [***b***](#cite_ref-Houk1979_4-1) Houk, Nancy; Cowley, A. P. (1979). *Michigan catalogue of two-dimensional spectral types for the HD stars*. Vol. 1. Ann Arbor, Michigan: Department of Astronomy, University of Michigan. [Bibcode](/source/Bibcode_(identifier)):[1978mcts.book.....H](https://ui.adsabs.harvard.edu/abs/1978mcts.book.....H).

1. ^ [***a***](#cite_ref-johnson1966_5-0) [***b***](#cite_ref-johnson1966_5-1) Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (1966). "UBVRIJKL Photometry of the Bright Stars". *Communications of the Lunar and Planetary Laboratory*. **4**: 99. [Bibcode](/source/Bibcode_(identifier)):[1966CoLPL...4...99J](https://ui.adsabs.harvard.edu/abs/1966CoLPL...4...99J).

1. ^ [***a***](#cite_ref-tic_6-0) [***b***](#cite_ref-tic_6-1) Stassun, Keivan G.; et al. (2019). ["The Revised TESS Input Catalog and Candidate Target List"](https://doi.org/10.3847%2F1538-3881%2Fab3467). *The Astronomical Journal*. **158** (4): 138. [arXiv](/source/ArXiv_(identifier)):[1905.10694](https://arxiv.org/abs/1905.10694). [Bibcode](/source/Bibcode_(identifier)):[2019AJ....158..138S](https://ui.adsabs.harvard.edu/abs/2019AJ....158..138S). [doi](/source/Doi_(identifier)):[10.3847/1538-3881/ab3467](https://doi.org/10.3847%2F1538-3881%2Fab3467).

1. **[^](#cite_ref-cardiel2021_7-0)** Cardiel, Nicolás; Zamorano, Jaime; Bará, Salvador; Sánchez De Miguel, Alejandro; Cabello, Cristina; Gallego, Jesús; García, Lucía; González, Rafael; Izquierdo, Jaime; Pascual, Sergio; Robles, José; Sánchez, Ainhoa; Tapia, Carlos (2021). ["Synthetic RGB photometry of bright stars: Definition of the standard photometric system and UCM library of spectrophotometric spectra"](https://doi.org/10.1093%2Fmnras%2Fstab997). *Monthly Notices of the Royal Astronomical Society*. **504** (3): 3730. [arXiv](/source/ArXiv_(identifier)):[2103.17009](https://arxiv.org/abs/2103.17009). [Bibcode](/source/Bibcode_(identifier)):[2021MNRAS.504.3730C](https://ui.adsabs.harvard.edu/abs/2021MNRAS.504.3730C). [doi](/source/Doi_(identifier)):[10.1093/mnras/stab997](https://doi.org/10.1093%2Fmnras%2Fstab997).

1. **[^](#cite_ref-balona2021_8-0)** Balona, Luis A.; Ozuyar, Dogus (2021). ["TESS Observations of be Stars: General Characteristics and the Impulsive Magnetic Rotator Model"](https://doi.org/10.3847%2F1538-4357%2Fac1a77). *The Astrophysical Journal*. **921** (1): 5. [arXiv](/source/ArXiv_(identifier)):[2008.06288](https://arxiv.org/abs/2008.06288). [Bibcode](/source/Bibcode_(identifier)):[2021ApJ...921....5B](https://ui.adsabs.harvard.edu/abs/2021ApJ...921....5B). [doi](/source/Doi_(identifier)):[10.3847/1538-4357/ac1a77](https://doi.org/10.3847%2F1538-4357%2Fac1a77).

1. **[^](#cite_ref-gontcharov2012_9-0)** Gontcharov, G. A. (2012). "Dependence of kinematics on the age of stars in the solar neighborhood". *Astronomy Letters*. **38** (12): 771. [arXiv](/source/ArXiv_(identifier)):[1606.08814](https://arxiv.org/abs/1606.08814). [Bibcode](/source/Bibcode_(identifier)):[2012AstL...38..771G](https://ui.adsabs.harvard.edu/abs/2012AstL...38..771G). [doi](/source/Doi_(identifier)):[10.1134/S1063773712120031](https://doi.org/10.1134%2FS1063773712120031).

1. **[^](#cite_ref-SIMBAD_10-0)** ["A Cen"](http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=A+Cen). *[SIMBAD](/source/SIMBAD)*. [Centre de données astronomiques de Strasbourg](/source/Centre_de_donn%C3%A9es_astronomiques_de_Strasbourg). Retrieved 2020-02-27.

1. **[^](#cite_ref-Eggleton2008_11-0)** Eggleton, P. P.; Tokovinin, A. A. (September 2008). ["A catalogue of multiplicity among bright stellar systems"](https://doi.org/10.1111%2Fj.1365-2966.2008.13596.x). *Monthly Notices of the Royal Astronomical Society*. **389** (2): 869–879. [arXiv](/source/ArXiv_(identifier)):[0806.2878](https://arxiv.org/abs/0806.2878). [Bibcode](/source/Bibcode_(identifier)):[2008MNRAS.389..869E](https://ui.adsabs.harvard.edu/abs/2008MNRAS.389..869E). [doi](/source/Doi_(identifier)):[10.1111/j.1365-2966.2008.13596.x](https://doi.org/10.1111%2Fj.1365-2966.2008.13596.x). [S2CID](/source/S2CID_(identifier)) [14878976](https://api.semanticscholar.org/CorpusID:14878976).

1. **[^](#cite_ref-hanuschik1996_12-0)** Hanuschik, R. W. (1996). "On the structure of be star disks". *Astronomy and Astrophysics*. **308**: 170. [Bibcode](/source/Bibcode_(identifier)):[1996A&A...308..170H](https://ui.adsabs.harvard.edu/abs/1996A&A...308..170H).

## External links

- Wikisky [image](http://www.wikisky.org/?ra=11.579349499999998&de=-54.26409000000002&zoom=8&show_grid=1&show_constellation_lines=1&show_constellation_boundaries=1&show_const_names=0&show_galaxies=1&show_box=1&box_ra=11.5793495&box_de=-54.26409&box_width=50&box_height=50&img_source=DSS2) of HD 100673 (A Centauri)

v t e Constellation of Centaurus List of stars in Centaurus Centaurus in Chinese astronomy Stars Bayer α A (Rigil Kentaurus) B (Toliman) C (Proxima Centauri) β (Hadar) γ δ ε ζ (Leepwal) η θ (Menkent) ι (Kulou) κ λ μ ν (Heng) ξ1 ξ2 ο1 ο2 π ρ σ τ υ1 υ2 φ χ ψ x1 x2 C3 D E F G H J K M N Q Flamsteed 1 (i) 2 (g) 3 (k) 4 (h) Variable R T V Y RR SV SX BV DY UY V346 V553 V744 V752 V761 (a) V763 (C1) V766 V779 (Krzemiński's star) V803 V810 V816 (Przybylski's Star) V831 V842 V885 V886 V863 V1032 V1369 V1400 V1935 HR 4460 (A) 4466 (C2) 4499 4522 4523 4537 (j) 4546 (B) 4721 4748 (u) 4796 4817 (l) 4831 (w) 4874 (p) 4888 (e) 4889 (n) 4940 (f) 4979 4989 5006 (r) 5041 (m) 5089 (d) 5174 (z) 5222 (y) 5224 5241 5297 5358 (v) 5371 5471 (b) 5485 (c1) 5489 (c2) HD 97413 98176 100453 101581 101930 102117 (Uklun) 103197 107914 108236 109749 110113 113538 113766 114386 114729 115600 116434 (Matza) 117207 117618 (Dofida) 117939 120411 121228 121504 124448 (Popper's Star) 125072 125595 131399 Other 2MASS J1126−5003 2M1207 Gaia BH2 HD 131399 Ab PSR B1259−63 PSR J1311−3430 TOI-763 WASP-15 (Nyamien) WASP-41 WASP-42 WASP-167/KELT-13 Exoplanets 2M1207b b Centauri b HD 101930 b HD 102117 b (Leklsullun) HD 103197 b HD 109749 b HD 113538 b c HD 114386 b HD 114729 b HD 117207 b HD 117618 b (Noifasui) HD 121504 b HIP 65426 b (Najsakopajk) HIP 67522 b NGTS-13b Proxima Centauri b c d WASP-15b (Asye) Star clusters NGC 3766 4230 4507 5281 5286 5316 5460 5617 5662 Other IC 2944 ω Centauri Scorpius–Centaurus association Stock 16 Nebulae NGC 3918 5307 Other Boomerang Nebula Fleming 1 G292.0+1.8 G306.3-0.9 Gum 41 IC 2944 IRAS 13208−6020 RCW 79 RCW 86 Southern Crab Nebula SuWt 2 Galaxies NGC 3557 3568 3749 3783 4444 4603 4622 4650A 4683 4696 4706 4709 4729 4730 4743 4744 4909 4930 4945 4976 5011 A 5026 5064 5082 5090 5091 5102 5114 5121 5128 (Centaurus A) 5161 5206 5253 5266 5291 5398 5408 5419 5483 5516 Other ESO 269-57 ESO 325-4 ESO 383-76 ESO 444-46 Fourcade-Figueroa Object IC 3370 IC 4214 IC 4329A IRAS 13224−3809 J1144−4308 LEDA 677373 PKS 1144−379 PKS 1353−341 PKS 1424−418 Galaxy clusters Abell S740 Centaurus Cluster Shapley Supercluster Astronomical events GW190521 SN 185 SN 1895B (Z) SN 1972E SN 1986G J1407b SN 2019so Category

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Adapted from the Wikipedia article [HD 100673](https://en.wikipedia.org/wiki/HD_100673) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/HD_100673?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.