19 Draconis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Draco |
| Right ascension | 16h 56m 01.68925s[1] |
| Declination | +65° 08′ 05.2631″[1] |
| Apparent magnitude (V) | 4.89[2] |
| Characteristics | |
| Spectral type | F8V[3] |
| U−B color index | -0.03[2] |
| B−V color index | +0.485[2] |
| Astrometry | |
| Radial velocity (Rv) | -21.00 ± 0.8[4] km/s |
| Proper motion (μ) | RA: 237.79[1] mas/yr Dec.: 50.84[1] mas/yr |
| Parallax (π) | 65.54 ± 0.33[1] mas |
| Distance | 49.8 ± 0.3 ly (15.26 ± 0.08 pc) |
| Absolute magnitude (MV) | 3.98[5] |
| Orbit[5] | |
| Period (P) | 52.1089 ± 0.0001 d |
| Semi-major axis (a) | 20.0 mas |
| Eccentricity (e) | 0.2221 ± 0.0002 |
| Inclination (i) | 90.5 ± 2.2° |
| Longitude of the node (Ω) | 23.5 ± 2.0° |
| Periastron epoch (T) | JD 2453427.880 ± 0.007 |
| Argument of periastron (ω) (secondary) | 338.46 ± 0.05° |
| Semi-amplitude (K1) (primary) | 17.465 ± 0.004 km/s |
| Details[5] | |
| 19 Dra A | |
| Mass | 1.04 M☉ |
| Radius | 1.2 R☉ |
| Luminosity | 2.02 L☉ |
| Temperature | 6298 ± 80 K |
| Metallicity | Z = 0.013 ± 0.004 |
| Age | 4.7 Gyr |
| 19 Dra B | |
| Mass | 0.37 M☉ |
| Radius | 0.3 R☉ |
| Luminosity | 0.02 L☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
19 Draconis, also known as h Draconis, is a star in the constellation Draco. Its apparent magnitude is 4.89.[2] Based on its parallax, the system is located about 49.8 light-years (15.26 parsecs) away.[1]
19 Draconis is a binary star. Only the primary star can be detected, via Doppler shifts or perturbations around the system's barycenter. Using spectroscopy and astrometry, the nature of the secondary star can be inferred. The primary star is an F-type main-sequence star, 4% more massive than the Sun. Its surface temperature is about 6,298 K, and it emits just over twice the amount of energy that the Sun does. The secondary is only 37% as massive as the Sun, and its luminosity is only 2% that of the Sun. The two stars orbit each other every 52.1 days, and the system is about 4.7 billion years old.[5]
References
- 1 2 3 4 5 6 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.
- 1 2 3 4 Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV data. Bibcode:1986EgUBV........0M.
- ↑ Abt, Helmut A. (2009). "MK Classifications of Spectroscopic Binaries". The Astrophysical Journal Supplement. 180 (1): 117–18. Bibcode:2009ApJS..180..117A. doi:10.1088/0067-0049/180/1/117.
- ↑ 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.
- 1 2 3 4 Wang, Xiaoli; Ren, Shulin; Fu, Yanning (2015). "Self-Consistent Orbits and Physical Properties for Eight Single-Lined Spectroscopic Binaries". The Astronomical Journal. 150 (4): 110. Bibcode:2015AJ....150..110W. doi:10.1088/0004-6256/150/4/110.