19 Draconis
 19 Draconis in optical light | ||
| Observation data 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] | |
| Absolute magnitude (MV) | 3.98[5] | |
Semi-amplitude (K1)(primary) | 17.465 ± 0.004 km/s | |
| Details Gyr | ||
| 19 Dra B | ||
| Mass | 0.37 M☉ | |
| Radius | 0.3 R☉ | |
| Luminosity | 0.02 L☉ | |
| Temperature | ~3963[note 1] K | |
HR 6315, SAO 17281 | ||
| Database references | ||
| SIMBAD | data | |
| ARICNS | data | |
19 Draconis, also known as h Draconis, is a
apparent visual magnitude of 4.89.[2] Based on its parallax, the system is located about 49.8 light-years (15.26 parsecs) away.[1] It is moving closer to the Earth with a heliocentric radial velocity of −21 km/s.[4]
This is a
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 with a stellar classification of F8V,[3] 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 system is about 4.7 billion years old.[5]
References
- ^ S2CID 18759600.
- ^ Bibcode:1986EgUBV........0M.
- ^ S2CID 122811461.
- ^ S2CID 119231169.
- ^ .
Notes
- Stefan–Boltzmann constant.
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