 ψ1 Draconis in optical light | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Draco |
| ψ1 Dra A | |
| Right ascension | 17h 41m 56.35536s[1] |
| Declination | +72° 08′ 55.8481″[1] |
| Apparent magnitude (V) | 4.58[2] |
| ψ1 Dra B | |
| Right ascension | 17h 41m 58.10460s[1] |
| Declination | +72° 09′ 24.8581″[1] |
| Apparent magnitude (V) | 5.82[3] |
| Characteristics | |
| ψ1 Dra A | |
| Spectral type | F5IV-V[4] |
| U−B color index | +0.01[2] |
| B−V color index | +0.43[2] |
| ψ1 Dra B | |
| Spectral type | F8V[5] |
| U−B color index | +0.04[2] |
| B−V color index | +0.525[2] |
| Astrometry | |
| ψ1 Dra A | |
| Radial velocity (Rv) | -13.30 ± 0.2[6] km/s |
| Proper motion (μ) | RA: 25.32[1] mas/yr Dec.: -268.47[1] mas/yr |
| Parallax (π) | 43.79 ± 0.45 mas[1] |
| Distance | 74.5 ± 0.8 ly (22.8 ± 0.2 pc) |
| ψ1 Dra B | |
| Radial velocity (Rv) | -11.20 ± 0.3[6] km/s |
| Proper motion (μ) | RA: 34.89[1] mas/yr Dec.: -275.94[1] mas/yr |
| Parallax (π) | 43.36 ± 0.51 mas[1] |
| Distance | 75.2 ± 0.9 ly (23.1 ± 0.3 pc) |
| Orbit[7] | |
| Primary | ψ1 Dra Aa |
| Companion | ψ1 Dra Ab |
| Period (P) | 6774+271 −167 d |
| Semi-major axis (a) | 9.1+0.4 −0.3 AU |
| Eccentricity (e) | 0.679+0.006 −0.004 |
| Inclination (i) | 31 ± 1° |
| Periastron epoch (T) | 2450388+169 −273 |
| Argument of periastron (ω) (secondary) | 32.6 ± 0.7° |
| Semi-amplitude (K1) (primary) | 5.18+0.04 −0.03 km/s |
| Semi-amplitude (K2) (secondary) | 11.1 ± 0.2 km/s |
| Details | |
| ψ1 Dra A | |
| Mass | 1.38+0.15 −0.08 / 0.70 ± 0.07[7] M☉ |
| Radius | 1.2–1.3[8] R☉ |
| Surface gravity (log g) | 3.90 ± 0.11[9] cgs |
| Temperature | 6544 ± 42 / 4400 ± 300[7] K |
| Metallicity [Fe/H] | −0.10 ± 0.05[9] dex |
| ψ1 Dra B | |
| Mass | 1.19 ± 0.07[9] M☉ |
| Radius | 1.5[8] R☉ |
| Surface gravity (log g) | 4.20 ± 0.12[9] cgs |
| Temperature | 6212 ± 75[9] K |
| Age | 3.3 ± 1.0 G[9] years |
| Other designations | |
| ψ1 Dra A: BD+72° 804, HD 162003, HIP 86614, HR 6636, SAO 8890[4] | |
| ψ1 Dra B: BD+72° 805, HD 162004, HIP 86620, HR 6637, SAO 8891[5] | |
| Database references | |
| SIMBAD | ψ1 Dra AB |
| ψ1 Dra A | |
| ψ1 Dra B | |
Psi1 Draconis (ψ1 Draconis, abbreviated Psi1 Dra, ψ1 Dra), also designated 31 Draconis, is a triple star system in the northern constellation of Draco. The system is fairly close, and is located about 75 light-years (23 parsecs) from the Sun, based on its parallax.[1]
Psi1 Draconis was considered a binary star consisting of an F-type subgiant and an F-type main-sequence star, designated Psi1 Draconis A (officially named Dziban /ˈzaɪbən/, from the traditional name of the system)[10] and Psi1 Draconis B, respectively. In 2015, Psi1 Draconis A was itself found to be a double-lined spectroscopic binary, making the system a triple. The companion to Psi1 Draconis A was designated Psi1 Draconis C by its discoverers.[7]
Also in 2015, Psi1 Draconis B was discovered to be orbited by an exoplanet, designated Psi1 Draconis Bb.[9]
- ^ a b c d e f g h i j k 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. S2CID 18759600.
- ^ a b c d e Johnson, H. L. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99. Bibcode:1966CoLPL...4...99J.
- ^ Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
- ^ a b "psi01 Dra A". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 17 March 2017.
- ^ a b "psi01 Dra B". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 17 March 2017.
- ^ a b Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
- ^ a b c d Gullikson, Kevin; Endl, Michael; Cochran, William D.; MacQueen, Phillip J. (2015). "Mining Planet Search Data for Binary Stars: The ψ1 Draconis system". The Astrophysical Journal. 815 (1): 62. arXiv:1511.01903. Bibcode:2015ApJ...815...62G. doi:10.1088/0004-637X/815/1/62. S2CID 59408173.
- ^ a b Pasinetti Fracassini, L. E.; et al. (2001). "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) – Third edition – Comments and statistics". Astronomy & Astrophysics. 367 (2): 521–24. arXiv:astro-ph/0012289. Bibcode:2001A&A...367..521P. doi:10.1051/0004-6361:20000451. S2CID 425754.
- ^ a b c d e f g Endl, Michael; Brugamyer, Erik J.; Cochran, William D.; MacQueen, Phillip J.; Robertson, Paul; Meschiari, Stefano; Ramirez, Ivan; Shetrone, Matthew; Gullikson, Kevin; Johnson, Marshall C.; Wittenmyer, Robert; Horner, Jonathan; Ciardi, David R.; Horch, Elliott; Simon, Attila E.; Howell, Steve B.; Everett, Mark; Caldwell, Caroline; Castanheira, Barbara G. (2016). "Two New Long-Period Giant Planets from the Mcdonald Observatory Planet Search and Two Stars with Long-Period Radial Velocity Signals Related to Stellar Activity Cycles". The Astrophysical Journal. 818 (1): 34. arXiv:1512.02965. Bibcode:2016ApJ...818...34E. doi:10.3847/0004-637X/818/1/34. S2CID 39476347.
- ^ "Naming Stars". IAU.org. Retrieved 16 December 2017.