# HD 139319

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Triple star system in constellation Draco

HD 139319 A light curve for TW Draconis, plotted from TESS data[1] Observation data Epoch J2000 Equinox J2000 Constellation Draco Right ascension 15h 33m 51.0571s[2] Declination +63° 54′ 25.695″[2] Apparent magnitude (V) 7.46[3] Characteristics HD 139319A Spectral type A8V+K0III[4] Apparent magnitude (g) 7.39[2] HD 139319B Spectral type F7V[citation needed] Apparent magnitude (g) 9.65[5] Astrometry HD 139319A Proper motion (μ) RA: 11.44±0.03 mas/yr[2] Dec.: 22.39±0.02 mas/yr[2] Parallax (π) 6.0571±0.0179 mas[2] Distance 538 ± 2 ly (165.1 ± 0.5 pc) HD 139319B Radial velocity (Rv) 1.6±0.7[5] km/s Proper motion (μ) RA: 12.09±0.02 mas/yr[5] Dec.: 21.278±0.018 mas/yr[5] Parallax (π) 6.0345±0.0160 mas[5] Distance 540 ± 1 ly (165.7 ± 0.4 pc) Orbit[6] Primary TW Draconis A Name TW Draconis B Period (P) 2.8068491 d Semi-major axis (a) 0.057 AU Inclination (i) 86.8° Semi-amplitude (K1) (primary) 64.05 km/s Semi-amplitude (K2) (secondary) 150 km/s Details[7] TW Draconis A Mass 2.16±0.11 M☉ Radius 2.64±0.04 R☉ Surface gravity (log g) 3.928±0.026 cgs Temperature 7815±92 K TW Draconis B Mass 0.93±0.05 M☉ Radius 3.66±0.06 R☉ Surface gravity (log g) 3.314±0.026 cgs Temperature 4442±32 K Other designations BD+64 1077, HIP 76196, 2MASS J15335104+6354257, GSC 04184-00061 HD 139319A: TW Draconis, TYC 4184-61-1, Gaia DR2 1640708022815757568 HD 139319B: TYC 4184-61-2, Gaia DR2 1640708022815757824 Database references SIMBAD data

**HD 139319** is a ternary system composed of the binary [Algol variable](/source/Algol_variable) star known as TW Draconis, and a [main-sequence](/source/Main_sequence) companion star at a separation of 3 arcseconds.[6] The system lies in the constellation of [Draco](/source/Draco_(constellation)) about 540 [light years](/source/Light_years) away.

## System

The primary star is an eclipsing, semi-detached binary, the brighter component of which is a pulsating star of [Delta Scuti](/source/Delta_Scuti_variable) type. Its pulsation frequency is 17.99 cycles per day.[4] Mass transfer between stars is ongoing in the system[8] with a transfer rate of 6.8×10−7M☉/year. The 2.8 day period of the Algol binary is cyclically variable with a period 116.04 years, possibly due to gravitational influence of the distant companion HD 139319B. Another three stars in the system are suspected.[6]

## References

1. **[^](#cite_ref-MAST_1-0)** ["MAST: Barbara A. Mikulski Archive for Space Telescopes"](https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html). Space Telescope Science Institute. Retrieved 8 December 2021.

1. ^ [***a***](#cite_ref-DR3A_2-0) [***b***](#cite_ref-DR3A_2-1) [***c***](#cite_ref-DR3A_2-2) [***d***](#cite_ref-DR3A_2-3) [***e***](#cite_ref-DR3A_2-4) Vallenari, A.; et al. (Gaia collaboration) (2023). ["*Gaia* Data Release 3. Summary of the content and survey properties"](https://doi.org/10.1051%2F0004-6361%2F202243940). *Astronomy and Astrophysics*. **674**: A1. [arXiv](/source/ArXiv_(identifier)):[2208.00211](https://arxiv.org/abs/2208.00211). [Bibcode](/source/Bibcode_(identifier)):[2023A&A...674A...1G](https://ui.adsabs.harvard.edu/abs/2023A&A...674A...1G). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/202243940](https://doi.org/10.1051%2F0004-6361%2F202243940). [S2CID](/source/S2CID_(identifier)) [244398875](https://api.semanticscholar.org/CorpusID:244398875). [Gaia DR3 record for this source](https://vizier.cds.unistra.fr/viz-bin/VizieR-4?-source=+I%2F355&-from=nav&-nav=cat%3AI%2F355%26tab%3A%7BI%2F355%2Fgaiadr3%7D%26key%3Asource%3D1355%2Fgaiadr3%26HTTPPRM%3A%26-out.add%3D.%26Source%3D%3D%3D1640708022815757568%26-go+%25%23Sesame%23%25%26) at [VizieR](/source/VizieR).

1. **[^](#cite_ref-SIMBAD_3-0)** ["TW Dra"](http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=TW+Dra). *[SIMBAD](/source/SIMBAD)*. [Centre de données astronomiques de Strasbourg](/source/Centre_de_donn%C3%A9es_astronomiques_de_Strasbourg). Retrieved 2021-12-13.

1. ^ [***a***](#cite_ref-Kim2003_4-0) [***b***](#cite_ref-Kim2003_4-1) Kim, S.-L.; Lee, J. W.; Kwon, S.-G.; Youn, J.-H.; Mkrtichian, D. E.; Kim, C. (2003), "Search for A–F Spectral type pulsating components in Algol-type eclipsing binary systems", *Astronomy & Astrophysics*, **405**: 231–236, [Bibcode](/source/Bibcode_(identifier)):[2003A&A...405..231K](https://ui.adsabs.harvard.edu/abs/2003A&A...405..231K), [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20030630](https://doi.org/10.1051%2F0004-6361%3A20030630)

1. ^ [***a***](#cite_ref-DR3B_5-0) [***b***](#cite_ref-DR3B_5-1) [***c***](#cite_ref-DR3B_5-2) [***d***](#cite_ref-DR3B_5-3) Vallenari, A.; et al. (Gaia collaboration) (2023). ["*Gaia* Data Release 3. Summary of the content and survey properties"](https://doi.org/10.1051%2F0004-6361%2F202243940). *Astronomy and Astrophysics*. **674**: A1. [arXiv](/source/ArXiv_(identifier)):[2208.00211](https://arxiv.org/abs/2208.00211). [Bibcode](/source/Bibcode_(identifier)):[2023A&A...674A...1G](https://ui.adsabs.harvard.edu/abs/2023A&A...674A...1G). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/202243940](https://doi.org/10.1051%2F0004-6361%2F202243940). [S2CID](/source/S2CID_(identifier)) [244398875](https://api.semanticscholar.org/CorpusID:244398875). [Gaia DR3 record for this source](https://vizier.cds.unistra.fr/viz-bin/VizieR-4?-source=+I%2F355&-from=nav&-nav=cat%3AI%2F355%26tab%3A%7BI%2F355%2Fgaiadr3%7D%26key%3Asource%3D1355%2Fgaiadr3%26HTTPPRM%3A%26-out.add%3D.%26Source%3D%3D%3D1640708022815757824%26-go+%25%23Sesame%23%25%26) at [VizieR](/source/VizieR).

1. ^ [***a***](#cite_ref-Tkachenko2010_6-0) [***b***](#cite_ref-Tkachenko2010_6-1) [***c***](#cite_ref-Tkachenko2010_6-2) Liao, Wen-Ping; Qian, Sheng-Bang; Zejda, Miloslav; Zhu, Li-Ying; Li, Lin-Jia (2016), "Lunar-based Ultraviolet Telescope study of the well-known Algol-type binary TW Dra", *Research in Astronomy and Astrophysics*, **16** (6): 009, [Bibcode](/source/Bibcode_(identifier)):[2016RAA....16...94L](https://ui.adsabs.harvard.edu/abs/2016RAA....16...94L), [doi](/source/Doi_(identifier)):[10.1088/1674-4527/16/6/094](https://doi.org/10.1088%2F1674-4527%2F16%2F6%2F094), [S2CID](/source/S2CID_(identifier)) [124656327](https://api.semanticscholar.org/CorpusID:124656327)

1. **[^](#cite_ref-7)** Bozic, H.; Nemravova, J.; Harmanec, P. (2013), "Standard UBV photometry and improved physical properties of TW Dra", *Information Bulletin on Variable Stars*, **6086**: 1, [Bibcode](/source/Bibcode_(identifier)):[2013IBVS.6086....1B](https://ui.adsabs.harvard.edu/abs/2013IBVS.6086....1B)

1. **[^](#cite_ref-8)** Norton, A. J.; Lohr, M. E.; Smalley, B.; Wheatley, P. J.; West, R. G. (2016), "SuperWASP discovery and SALT confirmation of a semi-detached eclipsing binary that contains aδScuti star", *Astronomy & Astrophysics*, **587**: A54, [arXiv](/source/ArXiv_(identifier)):[1601.03198](https://arxiv.org/abs/1601.03198), [Bibcode](/source/Bibcode_(identifier)):[2016A&A...587A..54N](https://ui.adsabs.harvard.edu/abs/2016A&A...587A..54N), [doi](/source/Doi_(identifier)):[10.1051/0004-6361/201526881](https://doi.org/10.1051%2F0004-6361%2F201526881), [S2CID](/source/S2CID_(identifier)) [10625309](https://api.semanticscholar.org/CorpusID:10625309)

v t e Constellation of Draco List of stars in Draco Draco in Chinese astronomy Stars Bayer α (Thuban) β (Rastaban) γ (Eltanin) δ (Altais) ε (Tyl) ζ (Aldhibah) η (Athebyne) θ ι (Edasich) κ λ (Giausar) μ (Alrakis) ν (Kuma) ξ (Grumium) ο π ρ σ (Alsafi) τ υ φ χ ψ1 (Dziban) ψ2 ω Flamsteed 4 6 7 (Tianyi) 8 (Taiyi) 10 (i) 15 (A) 18 (g) 19 (h) 26 36 39 (b) 42 (Fafnir) 45 (d) 50 59 64 (e) 68 Variable TW YY AG BY CL CM CX DO EK HP V581 HR 3751 4126 4934 5811 6237 6518 6618 (Alruba) 6817 7137 7783 HD 109246 (Funi) 101364 128717 147379 156279 158259 176693 191939 Other 2MASS 1237+6526 2MASS J17554042+6551277 G 240-72 GD 356 Gliese 420 Gliese 625 Gliese 687 GRW +70 8247 Kepler-4 Kepler-10 Kepler-12 Kepler-90 Kepler-296 KOI-256 LP 71-82 Qatar-1 SDSS J1240+6710 Struve 2398 TOI-1136 WD 1856+534 WISE 1647+5632 WISE 1841+7000 Exoplanets HD 139357 b HD 167042 b ι Dra b (Hypatia) Kepler-4b Kepler-10b c Kepler-12b Kepler-90e f g h i Kepler-296b c d e f TOI-1452 b TrES-2b Star clusters LAMOST 1 Nebulae Cat's Eye Nebula NGC 6742 Galaxies NGC 3147 3197 3735 4121 4125 4221 4236 4319 4331 4332 4363 4441 4513 4545 4589 5678 5777 5866 5866B 5879 5905 5907 5949 5963 5965 5982 5985 6090 6248 6285 6286 6338 6340 6365 6373 6394 6412 6503 6505 6566 6621 6622 6670 6676 6786 6789 Other 1ES 1927+654 1ES 1959+650 3C 249.1 3C 305 3C 319 3C 343 3C 343.1 3C 351 3C 356 3C 371 3C 380 3C 390.3 3C 401 4C +72.26 4C 73.08 8C 1241+735 Abell 2218 BCG Bean galaxy Beaver galaxy BZQ J1727+5510 Draco Dwarf Draco II GB 1508+5714 Goldfish galaxy H1821+643 HFLS3 IERS B1946+708 IRAS F17179+5444 IRAS 18580+6527 J120011.1+680924.8 KKR 25 Markarian 817 Markarian 876 Original TRG PGC 39058 Porphyrion QSO B1823+568 RGZ J172749.5+534647 S5 1803+784 S5 2007+777 SDSS J1715+6008 Tadpole Galaxy UGC 9391 UGC 9405 UGC 11241 UGC 11411 WISEA J145223.62+611707.5 WN B1851+5707 Galaxy clusters Abell 2218 CL1358+62 Draco Supercluster NGC 5866 Group Astronomical events SN 2003jb SN 2005B SN 2016aps Swift J1644+57 Category

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