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39 Draconis

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This article is about b Draconis; it is not to be confused with β (beta) Draconis.
39 Draconis
Location of 39 Draconis (circled in red)
Observation data
Epoch J2000      Equinox J2000
Constellation Draco[1]
A
Right ascension 18h 23m 54.60689s[2]
Declination +58° 48′ 02.6667″[2]
Apparent magnitude (V) 5.06[3]
B
Right ascension 18h 23m 54.51639s[4]
Declination +58° 48′ 06.3674″[4]
Apparent magnitude (V) 8.07[3]
Characteristics
Evolutionary stage main sequence[2][5]
Spectral type A1V + F5V[6]
U−B color index +0.06[7]
B−V color index +0.10[7]
Astrometry
Radial velocity (Rv)−24.53±0.23[8] km/s
A
Proper motion (μ) RA: −37.322[2] mas/yr
Dec.: +62.892[2] mas/yr
Parallax (π)17.1615±0.0631 mas[2]
Distance190.1 ± 0.7 ly
(58.3 ± 0.2 pc)
Absolute magnitude (MV)+1.31[9]
B
Proper motion (μ) RA: −41.742[4] mas/yr
Dec.: +61.076[4] mas/yr
Parallax (π)17.2293±0.0219 mas[4]
Distance189.3 ± 0.2 ly
(58.04 ± 0.07 pc)
Absolute magnitude (MV)+4.32[9]
Orbit[3]
Period (P)4,000±200 yr
Semi-major axis (a)6.6±0.3″
Eccentricity (e)0.553±0.005
Inclination (i)107.7±0.12°
Longitude of the node (Ω)179.9±0.10°
Periastron epoch (T)5671.40±12.08
Argument of periastron (ω)
(secondary)		128.0±2.2°
Details
39 Dra A
Mass2.12[9] M☉
Radius2.3[10] R☉
Luminosity27[10] L☉
Surface gravity (log g)4.04[10] cgs
Temperature8,630[10] K
Rotational velocity (v sin i)186[5] km/s
Age350[11] Myr
39 Dra B
Mass1.18[9] M☉
Radius1.15[10] R☉
Luminosity1.85[10] L☉
Surface gravity (log g)4.40[10] cgs
Temperature6,271[10] K
Rotation5.9 days[12]
Age2.6[13] Gyr
Other designations
b Dra, 39 Dra, BD+58°1809, HD 170073, HIP 90156, HR 6923, SAO 30949[14]
Database references
SIMBAD39 Dra
39 Dra A
39 Dra B

39 Draconis is a wide binary star system in the northern circumpolar constellation of Draco. It has the Bayer designation b Draconis, while 39 Draconis is the Flamsteed designation. This system is visible to the naked eye as a dim, white-hued point of light with a combined apparent visual magnitude of 5.0.[1] Parallax measurements made by the Gaia spacecraft put it at a distance of 190 light-years, or 58 parsecs away from the Sun. The system is moving closer to the Earth with a heliocentric radial velocity of −24.5 km/s.[8]

The two components of 39 Draconis have an angular separation of 6.621″ and take almost 4,000 years to orbit each other.[3] The primary star is an early A-type main-sequence star, having 2.12 times the mass of the Sun with a visual magnitude of 5.06.[3] The secondary is a magnitude 8.07[3] F-type main-sequence star, and has 1.18 times the mass of the Sun.[9]

The 8th-magnitude star HD 238865 is listed in double star catalogues as component C.[15] It is separated from the other two stars by 90″ and lies at about the same distance.[16] It is itself a spectroscopic binary with an F8 primary and a red dwarf secondary orbiting every 2.7 days.[17][18]

References

[edit]
  1. ^ a b Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. XHIP record for this object at VizieR.
  2. ^ a b c d e f 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.
  3. ^ a b c d e f "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Archived from the original on 2017-08-01. Retrieved 2017-06-22.
  4. ^ a b c d e 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.
  5. ^ a b Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics. 537: A120. arXiv:1201.2052. Bibcode:2012A&A...537A.120Z. doi:10.1051/0004-6361/201117691.
  6. ^ Lutz, T. E.; Lutz, J. H. (1977). "Spectral classification and UBV photometry of bright visual double stars". The Astronomical Journal. 82: 431. Bibcode:1977AJ.....82..431L. doi:10.1086/112066.
  7. ^ a b Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
  8. ^ a b Pourbaix, D.; et al. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727–732. arXiv:astro-ph/0406573. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213. S2CID 119387088.
  9. ^ a b c d e Novakovic, B.; Todorovic, N. (2006). "Orbits of four double stars". Serbian Astronomical Journal. 172 (172): 21. Bibcode:2006SerAJ.172...21N. doi:10.2298/SAJ0672021N. S2CID 55352155.
  10. ^ a b c d e f g h Stassun, Keivan G.; et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467.
  11. ^ De Rosa, R. J.; Patience, J.; Wilson, P. A.; Schneider, A.; Wiktorowicz, S. J.; Vigan, A.; Marois, C.; Song, I.; MacIntosh, B.; Graham, J. R.; Doyon, R.; Bessell, M. S.; Thomas, S.; Lai, O. (2014). "The VAST Survey - III. The multiplicity of A-type stars within 75 pc". Monthly Notices of the Royal Astronomical Society. 437 (2): 1216. arXiv:1311.7141. Bibcode:2014MNRAS.437.1216D. doi:10.1093/mnras/stt1932.
  12. ^ Lin, Chia-Lung; Apai, Dániel; Giampapa, Mark S.; Ip, Wing-Huen (2024). "Scalable, Advanced Machine Learning Based Approaches for Stellar Flare Identification: Application to TESS Short-cadence Data and Analysis of a New Flare Catalog". The Astronomical Journal. 168 (6): 234. arXiv:2409.02540. Bibcode:2024AJ....168..234L. doi:10.3847/1538-3881/ad7956.
  13. ^ Ware, Austin; Young, Patrick; Truitt, Amanda; Spacek, Alexander (2022). "Continuous Habitable Zones: Using Bayesian Methods to Prioritize Characterization of Potentially Habitable Worlds". The Astrophysical Journal. 929 (2): 143. arXiv:2203.06259. Bibcode:2022ApJ...929..143W. doi:10.3847/1538-4357/ac5c4e.
  14. ^ "* b Dra". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 21 June 2017.
  15. ^ Mason, B. D.; et al. (2014). "The Washington Visual Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920.
  16. ^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  17. ^ De Rosa, R. J.; Patience, J.; Wilson, P. A.; Schneider, A.; Wiktorowicz, S. J.; Vigan, A.; Marois, C.; Song, I.; MacIntosh, B.; Graham, J. R.; Doyon, R.; Bessell, M. S.; Thomas, S.; Lai, O. (2014). "The VAST Survey - III. The multiplicity of A-type stars within 75 pc". Monthly Notices of the Royal Astronomical Society. 437 (2): 1216. arXiv:1311.7141. Bibcode:2014MNRAS.437.1216D. doi:10.1093/mnras/stt1932. S2CID 88503488.
  18. ^ Tokovinin, A. A.; Smekhov, M. G. (1995). "Spectroscopic components in multiple systems: ADS 11336C". Astronomy Letters. 21 (2): 247. Bibcode:1995AstL...21..247T.


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