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HD 139319

Coordinates: Sky map 15h 33m 51.0571s, +63° 54′ 25.6950″
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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
Declination +63° 54′ 25.6950″
Apparent magnitude (V) 7.46[2]
Characteristics
HD 139319A
Spectral type A8V+K0III [3]
Apparent magnitude (g) 7.39[4]
HD 139319B
Spectral type F7V
Apparent magnitude (g) 9.65[5]
Astrometry
HD 139319A
Proper motion (μ) RA: 11.44±0.03 mas/yr[4]
Dec.: 22.39±0.02 mas/yr[4]
Parallax (π)6.0571 ± 0.0179 mas[4]
Distance538 ± 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]
Distance540 ± 1 ly
(165.7 ± 0.4 pc)
Orbit[6]
PrimaryTW Draconis A
CompanionTW 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
Mass2.16±0.11 M
Radius2.64±0.04 R
Surface gravity (log g)3.928±0.026 cgs
Temperature7815±92 K
TW Draconis B
Mass0.93±0.05 M
Radius3.66±0.06 R
Surface gravity (log g)3.314±0.026 cgs
Temperature4442±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
SIMBADdata

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

System

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The primary star is an eclipsing, semi-detached binary, the brighter component of which is a pulsating star of Delta Scuti type. Its pulsation frequency is 17.99 cycles per day.[3] 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

[edit]
  1. ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
  2. ^ "TW Dra". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-12-13.
  3. ^ a b 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:2003A&A...405..231K, doi:10.1051/0004-6361:20030630
  4. ^ a b c Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  5. ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  6. ^ a b c 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:2016RAA....16...94L, doi:10.1088/1674-4527/16/6/094, S2CID 124656327
  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:2013IBVS.6086....1B
  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:1601.03198, Bibcode:2016A&A...587A..54N, doi:10.1051/0004-6361/201526881, S2CID 10625309