Astronomy:39 Draconis
From HandWiki
Short description: Wide binary star system in the constellation of Draco
  | |
| Observation data {{#ifeq:J2000|J2000.0 (ICRS)|Epoch J2000.0 Equinox J2000.0 (ICRS)| [[History:Epoch|Epoch J2000]] [[Astronomy:Equinox (celestial coordinates)|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] |
| U−B color index | +0.06[6] |
| B−V color index | +0.10[6] |
| Astrometry | |
| Radial velocity (Rv) | −24.53±0.23[7] km/s |
| A | |
| Proper motion (μ) | RA: −37.322[2] mas/yr Dec.: +62.892[2] mas/yr |
| Parallax (π) | 17.1615 ± 0.0631[2] mas |
| Distance | 190.1 ± 0.7 ly (58.3 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.31[8] |
| B | |
| Proper motion (μ) | RA: −41.742[4] mas/yr Dec.: +61.076[4] mas/yr |
| Parallax (π) | 17.2293 ± 0.0219[4] mas |
| Distance | 189.3 ± 0.2 ly (58.04 ± 0.07 pc) |
| Absolute magnitude (MV) | +4.32[8] |
| 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 | |
| Mass | 2.12[8] M☉ |
| Radius | 2.3[9] R☉ |
| Luminosity | 27[9] L☉ |
| Surface gravity (log g) | 4.04[9] cgs |
| Temperature | 8,630[9] K |
| Rotational velocity (v sin i) | 186[5] km/s |
| Age | 350[10] Myr |
| 39 Dra B | |
| Mass | 1.18[8] M☉ |
| Radius | 1.15[9] R☉ |
| Luminosity | 1.85[9] L☉ |
| Surface gravity (log g) | 4.40[9] cgs |
| Temperature | 6,271[9] K |
| Rotation | 5.9 days[11] |
| Age | 2.6[12] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | 39 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.[7]
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.[8]
The 8th-magnitude star HD 238865 is listed in double star catalogues as component C.[14] It is separated from the other two stars by 90″ and lies at about the same distance.[15] It is itself a spectroscopic binary with an F8 primary and a red dwarf secondary orbiting every 2.7 days.[16][17]
References
- ↑ 1.0 1.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A XHIP record for this object at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6.
- ↑ 4.0 4.1 4.2 4.3 4.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 5.0 5.1 Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics 537: A120. doi:10.1051/0004-6361/201117691. Bibcode: 2012A&A...537A.120Z.
- ↑ 6.0 6.1 Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode: 1986EgUBV........0M.
- ↑ 7.0 7.1 Pourbaix, D. et al. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics 424 (2): 727–732. doi:10.1051/0004-6361:20041213. Bibcode: 2004A&A...424..727P.
- ↑ 8.0 8.1 8.2 8.3 8.4 Novakovic, B.; Todorovic, N. (2006). "Orbits of four double stars". Serbian Astronomical Journal 172 (172): 21. doi:10.2298/SAJ0672021N. Bibcode: 2006SerAJ.172...21N.
- ↑ 9.0 9.1 9.2 9.3 9.4 9.5 9.6 9.7 Stassun, Keivan G. et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode: 2019AJ....158..138S.
- ↑ De Rosa, R. J.; Patience, J.; Wilson, P. A.; Schneider, A.; Wiktorowicz, S. J.; Vigan, A.; Marois, C.; Song, I. et al. (2014). "The VAST Survey - III. The multiplicity of A-type stars within 75 pc". Monthly Notices of the Royal Astronomical Society 437 (2): 1216. doi:10.1093/mnras/stt1932. Bibcode: 2014MNRAS.437.1216D.
- ↑ 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. doi:10.3847/1538-3881/ad7956. Bibcode: 2024AJ....168..234L.
- ↑ 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. doi:10.3847/1538-4357/ac5c4e. Bibcode: 2022ApJ...929..143W.
- ↑ "* b Dra". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+b+Dra.
- ↑ Mason, B. D. et al. (2014). "The Washington Visual Double Star Catalog". The Astronomical Journal 122 (6): 3466–3471. doi:10.1086/323920. Bibcode: 2001AJ....122.3466M.
- ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ De Rosa, R. J.; Patience, J.; Wilson, P. A.; Schneider, A.; Wiktorowicz, S. J.; Vigan, A.; Marois, C.; Song, I. et al. (2014). "The VAST Survey - III. The multiplicity of A-type stars within 75 pc". Monthly Notices of the Royal Astronomical Society 437 (2): 1216. doi:10.1093/mnras/stt1932. Bibcode: 2014MNRAS.437.1216D.
- ↑ Tokovinin, A. A.; Smekhov, M. G. (1995). "Spectroscopic components in multiple systems: ADS 11336C". Astronomy Letters 21 (2): 247. Bibcode: 1995AstL...21..247T.
 |  |
