# HD 130144

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Star in the constellation Boötes

HD 130144 The visual band light curve of EK Boötes, from AAVSO data[1] Observation data Epoch J2000 Equinox J2000 Constellation Boötes Right ascension 14h 46m 05.94566s[2] Declination +15° 07′ 54.4332″[2] Apparent magnitude (V) 5.33 to 5.71[3] Characteristics Spectral type M5III[4] U−B color index +1.26[5] B−V color index 1.335±0.021[6] Variable type Lb?[3] Astrometry Radial velocity (Rv) −22.52±0.65[7] km/s Proper motion (μ) RA: −85.49[2] mas/yr Dec.: +18.86[2] mas/yr Parallax (π) 4.04±0.38 mas[2] Distance 810 ± 80 ly (250 ± 20 pc) Absolute magnitude (MV) −1.17[6] Details Mass 3.1±0.5[4] M☉ Radius 210±21[4] R☉ Luminosity 521.51[6] L☉ Temperature 3,400[4] K Rotational velocity (v sin i) 8.5 or 11[4] km/s Other designations EK Boo, BD+15°2758, FK5 3168, HD 130144, HIP 72208, HR 5512, SAO 101200[8] Database references SIMBAD data

**HD 130144** is a [variable star](/source/Variable_star) in the northern [constellation](/source/Constellation) of [Boötes](/source/Bo%C3%B6tes_(constellation)). It has the [variable star designation](/source/Variable_star_designation) **EK Boötis** (or EK Boo), while *HD 130144* is the designation from the *[Henry Draper Catalogue](/source/Henry_Draper_Catalogue)*. The star is faintly visible to the [naked eye](/source/Naked_eye) with an [apparent visual magnitude](/source/Apparent_visual_magnitude) that ranges from 5.33 down to 5.71.[3] [Parallax](/source/Stellar_parallax) measurements provide a distance estimate of approximately 810 [light years](/source/Light_year) from the [Sun](/source/Sun). It is drifting closer with a [radial velocity](/source/Radial_velocity) of −23 km/s.[7]

The brightness of HD 130144 was discovered to be variable when the *[Hipparcos](/source/Hipparcos)* satellite data was analyzed. It was given its variable star designation in 1999.[9] This is an aging [red giant star](/source/Red_giant_star) with a [stellar classification](/source/Stellar_classification) of M5III.[4] It has an estimated 3.1 times the [mass of the Sun](/source/Mass_of_the_Sun) and has expanded to around 210 times the [Sun's radius](/source/Sun's_radius).[4] EK Boo is classified as a [slow irregular variable](/source/Slow_irregular_variable) that ranges in luminosity with an amplitude of 0.38 in magnitude and no apparent periodicity. This is an [X-ray source](/source/X-ray_astronomy), and was possibly the first M-type giant star to have a [magnetic field](/source/Stellar_magnetic_field) directly detected.[10] The strength of the field ranges from –0.1 to 8 [G](/source/Gauss_(unit)).[11]

HD 130144 has a high rotation rate for a star of this class, which may be the result of [dredge-up](/source/Dredge-up) of [angular momentum](/source/Angular_momentum) from the interior, or else a merger with an orbiting companion.[11] A long-term trend in the radial velocity data suggests this star has an orbiting companion. Most likely this is an active [red dwarf](/source/Red_dwarf) that is responsible for most of the X-ray emission from the system.[10] There is nearby [visual companion](/source/Visual_companion) at an angular separation of 0.20[″](/source/Second_of_arc) along a [position angle](/source/Position_angle) of 82.2° (as of 2010).[12]

## References

1. **[^](#cite_ref-aavso_1-0)** ["Download Data"](https://www.aavso.org/data-download). *aavso.org*. AAVSO. Retrieved 1 October 2021.

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) van Leeuwen, F. (November 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).

1. ^ [***a***](#cite_ref-Samus2017_3-0) [***b***](#cite_ref-Samus2017_3-1) [***c***](#cite_ref-Samus2017_3-2) Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", *[Astronomy Reports](/source/Astronomy_Reports)*, 5.1, **61** (1): 80–88, [Bibcode](/source/Bibcode_(identifier)):[2017ARep...61...80S](https://ui.adsabs.harvard.edu/abs/2017ARep...61...80S), [doi](/source/Doi_(identifier)):[10.1134/S1063772917010085](https://doi.org/10.1134%2FS1063772917010085), [S2CID](/source/S2CID_(identifier)) [125853869](https://api.semanticscholar.org/CorpusID:125853869).

1. ^ [***a***](#cite_ref-aa524_A57_4-0) [***b***](#cite_ref-aa524_A57_4-1) [***c***](#cite_ref-aa524_A57_4-2) [***d***](#cite_ref-aa524_A57_4-3) [***e***](#cite_ref-aa524_A57_4-4) [***f***](#cite_ref-aa524_A57_4-5) [***g***](#cite_ref-aa524_A57_4-6) Konstantinova-Antova, R.; et al. (December 2010), "Direct detection of a magnetic field in the photosphere of the single M giant EK Bootis. How common is magnetic activity among M giants?", *Astronomy and Astrophysics*, **524**: 9, [arXiv](/source/ArXiv_(identifier)):[1009.2001](https://arxiv.org/abs/1009.2001), [Bibcode](/source/Bibcode_(identifier)):[2010A&A...524A..57K](https://ui.adsabs.harvard.edu/abs/2010A&A...524A..57K), [doi](/source/Doi_(identifier)):[10.1051/0004-6361/201014503](https://doi.org/10.1051%2F0004-6361%2F201014503), [S2CID](/source/S2CID_(identifier)) [119184105](https://api.semanticscholar.org/CorpusID:119184105), A57.

1. **[^](#cite_ref-MERMILLIOD_5-0)** Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", *Catalogue of Eggen's UBV Data. SIMBAD*, [Bibcode](/source/Bibcode_(identifier)):[1986EgUBV........0M](https://ui.adsabs.harvard.edu/abs/1986EgUBV........0M).

1. ^ [***a***](#cite_ref-Anderson_Francis_2012_6-0) [***b***](#cite_ref-Anderson_Francis_2012_6-1) [***c***](#cite_ref-Anderson_Francis_2012_6-2) 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-Famaey2009_7-0) [***b***](#cite_ref-Famaey2009_7-1) Famaey, B.; et al. (2009), "Spectroscopic binaries among Hipparcos M giants,. I. Data, orbits, and intrinsic variations", *Astronomy and Astrophysics*, **498** (2): 627–640, [arXiv](/source/ArXiv_(identifier)):[0901.0934](https://arxiv.org/abs/0901.0934), [Bibcode](/source/Bibcode_(identifier)):[2009A&A...498..627F](https://ui.adsabs.harvard.edu/abs/2009A&A...498..627F), [doi](/source/Doi_(identifier)):[10.1051/0004-6361/200810698](https://doi.org/10.1051%2F0004-6361%2F200810698), [S2CID](/source/S2CID_(identifier)) [18739721](https://api.semanticscholar.org/CorpusID:18739721).

1. **[^](#cite_ref-SIMBAD_8-0)** ["EK Boo"](http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=EK+Boo), *[SIMBAD](/source/SIMBAD)*, [Centre de données astronomiques de Strasbourg](/source/Centre_de_donn%C3%A9es_astronomiques_de_Strasbourg), retrieved 2021-04-30.

1. **[^](#cite_ref-Kazarovets1999_9-0)** Kazarovets, E. V.; Samus, N. N.; Durlevich, O. V.; Frolov, M. S.; Antipin, S. V.; Kireeva, N. N.; Pastukhova, E. N. (January 1999). ["The 74th Special Name-list of Variable Stars"](https://ibvs.konkoly.hu/pub/ibvs/4601/4659.pdf) (PDF). *Information Bulletin on Variable Stars*. **4659**: 1–27. [Bibcode](/source/Bibcode_(identifier)):[1999IBVS.4659....1K](https://ui.adsabs.harvard.edu/abs/1999IBVS.4659....1K). Retrieved 6 December 2024.

1. ^ [***a***](#cite_ref-Georgiev_et_al_2020_10-0) [***b***](#cite_ref-Georgiev_et_al_2020_10-1) Georgiev, S.; et al. (July 2020), "Magnetism in Cool Evolved Stars: the M giants EK Bootis and β Pegasi", *Bulgarian Astronomical Journal*, **33**: 87, [Bibcode](/source/Bibcode_(identifier)):[2020BlgAJ..33...87G](https://ui.adsabs.harvard.edu/abs/2020BlgAJ..33...87G).

1. ^ [***a***](#cite_ref-Renada_et_al_2009_11-0) [***b***](#cite_ref-Renada_et_al_2009_11-1) Konstantinova-Antova, Renada; Aurière, Michel; Schröder, Klaus-Peter; Petit, Pascal (April 2009), "Dynamo-generated magnetic fields in fast rotating single giants", *Cosmic Magnetic Fields: From Planets, to Stars and Galaxies, Proceedings of the International Astronomical Union, IAU Symposium*, vol. 259, no. S259, pp. 433–434, [arXiv](/source/ArXiv_(identifier)):[0901.1537](https://arxiv.org/abs/0901.1537), [Bibcode](/source/Bibcode_(identifier)):[2009IAUS..259..433K](https://ui.adsabs.harvard.edu/abs/2009IAUS..259..433K), [doi](/source/Doi_(identifier)):[10.1017/S1743921309031020](https://doi.org/10.1017%2FS1743921309031020), [S2CID](/source/S2CID_(identifier)) [119199670](https://api.semanticscholar.org/CorpusID:119199670)

1. **[^](#cite_ref-Horch2011_12-0)** Horch, Elliott P.; et al. (February 2011), ["Observations of Binary Stars with the Differential Speckle Survey Instrument. II. Hipparcos Stars Observed in 2010 January and June"](http://authors.library.caltech.edu/22553/1/Horch2011p12763Astron_J.pdf) (PDF), *The Astronomical Journal*, **141** (2): 13, [Bibcode](/source/Bibcode_(identifier)):[2011AJ....141...45H](https://ui.adsabs.harvard.edu/abs/2011AJ....141...45H), [doi](/source/Doi_(identifier)):[10.1088/0004-6256/141/2/45](https://doi.org/10.1088%2F0004-6256%2F141%2F2%2F45), [S2CID](/source/S2CID_(identifier)) [27904496](https://api.semanticscholar.org/CorpusID:27904496), 45.

## External links

- [HR 5512](http://webviz.u-strasbg.fr/viz-bin/VizieR-S?HR%205512)

- [Image HD 130144](http://aladin.u-strasbg.fr/AladinPreview?-c=14+46+05.9459%2B15+07+54.436&ident=V*+EK+Boo&submit=Aladin+previewer)

v t e Constellation of Boötes Boötes in Chinese astronomy Boötes Void List of stars in Boötes Stars Bayer α (Arcturus) β (Nekkar) γ (Seginus) δ (Qigong) ε (Izar, Pulcherrima) ζ η (Muphrid) θ ι κ λ (Xuange) μ1 (Alkalurops) μ2 ν1 ν2 ξ ο π ρ (Kalasungsang) σ (Genghe) τ (Tepiamenit) υ φ χ ψ ω Flamsteed 1 2 3 6 (e) 7 9 10 11 12 (d) 13 14 15 18 20 22 (f) 24 (g) 26 31 32 33 34 (Alrumh) 38 (Merga) 39 40 44 (Quadrans) 45 (c) 46 (b) 47 (k) 50 Variable R S T RX ZZ AB BL BP BX BY CE CH CI CN CP CR CX CY (101 Vir) DE EK HN HP HD 118508 118889 122563 125040 125351 (A) 125658 126128 126129 126141 126200 126271 127304 127334 127726 128093 128198 129132 129357 130084 130603 130917 131040 131473 131496 (Arcalís) 132029 132406 132563 134064 134335 135438 135530 135944 141399 Other 2MASS J15031961+2525196 CFBDSIR 1458+10 Gliese 526 HAT-P-4 LHS 2924 PSR J1544+4937 SDSS J1416+1348 SDSS J1433+1011 TVLM 513-46546 WASP-14 WD 1425+540 ZTF J153932.16+502738.8 Exoplanets HAT-P-4b HD 128311 b c HD 132406 b HD 136418 b (Awasis) τ Boötis b TOI-1853 b WASP-14b Star clusters NGC 5466 Galaxies NGC 5008 5248 5251 5416 5490 5500 5504 5508 5514 5523 5529 5532 5533 5535 5539 5541 5544 5545 5548 5557 5559 5562 5579 5582 5591 5601 5603 5609 5613 5614 5615 5624 5629 5630 5641 5642 5653 5665 5676 5681 5682 5683 5698 5714 5722 5752 5753 5754 5755 5772 5778 5784 5790 5820 5821 5829 5837 5857 5875 5876 5886 5888 5896 5929 5930 5966 Numbered I II III Other 3C 295 3C 299 3C 300 3C 303 3C 315 4C 19.44 4C +26.42 7C 1354+2552 Abell 2009 BCG Arp 302 B2 1420+32 B2 1441+26 CEERS-2112 CEERS-93316 CEERS2-588 CLASS B1359+154 Cloverleaf quasar DDO 190 EGS-zs8-1 EGS-z11-R0 EGSY8p7 H1426+428 IC 4397 IC 4461 IC 4462 IC 4481 IC 4516 IRAS 13349+2438 IRAS 14394+5332 IRAS 15206+3342 LEDA 2108986 MACS 1423-z7p64 MACS J1447.4+0827 BCG Maisie's Galaxy Markarian 463 Markarian 471 Markarian 478 MS 1455.0+2232 BCG MS 1512-cB58 NVSS J141343+433945 OQ 172 OQ 530 PG 1411+442 PG 1543+489 PGC 93125 PGC 1470080 PKS 1345+125 PKS 1413+135 QSO B1422+202 RBS 1467 RGZ J145001.5+144747 RGZ J145039.8+441829 SBS 1415+437 SDSS J135646.10+102609.0 SDSS J1430+2303 Teacup galaxy UGC 8669 UGC 9128 UGC 9425 UGC 9684 UGC 9796 ULAS J1342+0928 VV 191 Galaxy clusters Abell 1795 Abell 1991 BoRG-58 IDCS J1426.5+3508 Astronomical events GRB 990123 GRB 080319B SCP 06F6 SN 2003fg SN 2005bc SN 2020tlf Category

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Adapted from the Wikipedia article [HD 130144](https://en.wikipedia.org/wiki/HD_130144) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/HD_130144?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.