39 Draconis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Draco |
| Right ascension | 18h 23m 54.60641s[1] |
| Declination | +58° 48′ 02.6446″[1] |
| Apparent magnitude (V) | 5.034[2] (5.06 + 8.07)[3] |
| Characteristics | |
| Spectral type | A1V + F5V[4] |
| U−B color index | +0.06[5] |
| B−V color index | +0.10[5] |
| Astrometry | |
| Radial velocity (Rv) | -24.53 ± 0.23[6] km/s |
| Proper motion (μ) | RA: -37.82[1] mas/yr Dec.: 61.60[1] mas/yr |
| Parallax (π) | 17.71 ± 0.35 mas[1] |
| Distance | 184 ± 4 ly (56 ± 1 pc) |
| Absolute magnitude (MV) | 1.31 / 4.32[7] |
| Orbit[3] | |
| Period (P) | 3962.50 ± 209.26 yr |
| Semi-major axis (a) | 6.621 ± 0.325″ |
| 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 ± 2.18° |
| Details | |
| 39 Dra A | |
| Mass | 2.12[7] M☉ |
| Radius | 2.3[8] R☉ |
| Surface gravity (log g) | 4.05 ± 0.07[8] cgs |
| Temperature | 8710[8] K |
| 39 Dra B | |
| Mass | 1.18[7] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | 39 Dra |
| 39 Dra A | |
| 39 Dra B | |
39 Draconis, also known as b Draconis, is a wide binary star in the constellation Draco. Its apparent magnitude is 5.034.[2] Parallax measurements made by the Hipparcos spacecraft put it at a distance of 184 light-years, or 56 parsecs away.[1]
The two components of 39 Draconis are separated by 6.621″ and take almost 4,000 years to orbit each other. The primary star is an early A-type main-sequence star, 2.12 times the mass of the Sun. The secondary star is an F-type main-sequence star, and is 1.18 times the mass of the Sun.[7]
References
- ^ a b c d e f van Leeuwen, F.; et al. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
- ^ a b c "* b Dra". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 21 June 2017.
- ^ a b "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory.
- ^ 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.
- ^ 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 "Compilation of Eggen's UBV data, transformed to UBV (unpublished)".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.
- ^ Pourbaix, D.; et al. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727. arXiv:astro-ph/0406573. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213.
- ^ a b c d Novakovic, B.; Todorovic, N. (2006). "Orbits of four double stars". Serbian Astronomical Journal. 172 (172): 21. Bibcode:2006SerAJ.172...21N. doi:10.2298/SAJ0672021N.
- ^ a b c Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555–562. arXiv:astro-ph/9911002. Bibcode:1999A&A...352..555A.
| Stars |
| ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| |||||||||||||
| |||||||||||||
| |||||||||||||
| Galaxies |
| ||||||||||||
| |||||||||||||
| |||||||||||||
 | This main-sequence-star-related article is a stub. You can help Wikipedia by expanding it. |