19 Draconis

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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
BD+65° 1157, GJ 648, HD 153597, HIP 82860, HR 6315, SAO 17281
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[edit]

  1. ^ 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. Bibcode:2007A&A...474..653V. arXiv:0708.1752Freely accessible. doi:10.1051/0004-6361:20078357. 
  2. ^ a b c d Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV data. Bibcode:1986EgUBV........0M. 
  3. ^ 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. 
  4. ^ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. Bibcode:2006AstL...32..759G. arXiv:1606.08053Freely accessible. doi:10.1134/S1063773706110065. 
  5. ^ a b c d 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.