{{Short description|Star in the constellation Draco}} {{Starbox begin}} {{Starbox image | image= {{Location mark |image=Draco constellation map.svg|alt=|float=center|width=280 |label=|position=right |mark=Red circle.svg|mark_width=10|mark_link=19 Dra |x=436|y=704 }} |caption=Location of 19 Dra (circled in red) }} {{Starbox observe |epoch=[[J2000]] |constell=[[Draco (constellation)|Draco]] |ra={{RA|16|56|01.68925}}<ref name=HIP>{{cite journal|title=Validation of the new Hipparcos reduction|url=http://www.aanda.org/index.php?option=com_article&access=bibcode&Itemid=129&bibcode=2007A%2526A...474..653VFUL|author=van Leeuwen, F.|display-authors=etal|journal=Astronomy and Astrophysics|volume=474|issue=2|pages=653–664|date=2007|arxiv=0708.1752|bibcode=2007A&A...474..653V|doi=10.1051/0004-6361:20078357|s2cid = 18759600}}</ref> |dec={{DEC|+65|08|05.2631}}<ref name=HIP/> |appmag_v=4.89<ref name=EgUBV/> }} {{Starbox character |type=[[main sequence]]<ref name=dr3>{{cite Gaia DR3|1635375460142367104}}</ref> |class=F8V<ref name=Abt>{{cite journal|last=Abt, Helmut A.|date=2009|title=MK Classifications of Spectroscopic Binaries|journal=The Astrophysical Journal Supplement|volume=180|issue=1|pages=117–18|doi=10.1088/0067-0049/180/1/117 |bibcode=2009ApJS..180..117A|s2cid=122811461 }}</ref> |b-v=+0.485<ref name=EgUBV>{{cite journal|author1=Mermilliod, J.-C.|title=Compilation of Eggen's UBV data, transformed to UBV (unpublished)|journal=Catalogue of Eggen's UBV Data|url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?1986EgUBV........0M&db_key=AST&nosetcookie=1|date=1986|bibcode= 1986EgUBV........0M}}</ref> |u-b=-0.03<ref name=EgUBV/> |variable= }} {{Starbox astrometry |radial_v=−21.00 ± 0.8<ref name=Gontcharov2006>{{cite journal|title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system|author=Gontcharov, G. A.|date=2006|journal=Astronomy Letters|volume=32|issue=11|pages=759–771|bibcode=2006AstL...32..759G|doi=10.1134/S1063773706110065|arxiv=1606.08053|s2cid=119231169}}</ref> |prop_mo_ra=237.79<ref name=HIP/> |prop_mo_dec=50.84<ref name=HIP/> |parallax=65.54 |p_error=0.33 |parallax_footnote=<ref name=HIP/> |absmag_v=3.98<ref name=Wang/> }} {{Starbox orbit |reference=<ref name=Wang>{{cite journal|bibcode=2015AJ....150..110W|doi=10.1088/0004-6256/150/4/110|title=Self-Consistent Orbits and Physical Properties for Eight Single-Lined Spectroscopic Binaries|journal=The Astronomical Journal|volume=150|issue=4|pages=110|year=2015|last1=Wang|first1=Xiaoli|last2=Ren|first2=Shulin|last3=Fu|first3=Yanning|doi-access=free}}</ref> |period_unitless=52.1089 ± 0.0001 d |axis_unitless=20.0 mas |inclination=90.5 ± 2.2 |node=23.5 ± 2.0 |periastron=JD 2453427.880 ± 0.007 |eccentricity=0.2221 ± 0.0002 |periarg=338.46 ± 0.05 |k1=17.465 ± 0.004 }} {{Starbox detail |source=<ref name=Wang/> |component1=19 Dra A |mass=1.04 |radius=1.2 |temperature=6298 ± 80 |luminosity=2.02 |metal=Z {{=}} 0.013 ± 0.004 |rotational_velocity= |age_gyr=4.7<!-- 10^9.67 yr --> |component2=19 Dra B |mass2=0.37 |temperature2=~3963<ref group="note">From ''L'' = 4π''R''<sup>2</sup>σ''T''<sub>eff</sub><sup>4</sup>, rearranging to make ''T''<sub>eff</sub> = (''L'' / 4π''R''<sup>2</sup>σ)<sup>1/4</sup>. Where ''L'' is the luminosity, ''R'' is the radius, ''T''<sub>eff</sub> is the effective surface temperature and ''σ'' is the [[Stefan–Boltzmann constant]].</ref> |luminosity2=0.02 |radius2=0.3 }} {{Starbox catalog |names={{odlist|BD=+65°1157|GJ=648|HD=153597|HIP=82860|HR=6315|SAO=17281}} }} {{Starbox reference |Simbad=19+Dra |ARICNS=01349 }} {{Starbox end}}

[[Image:19 Draconis.jpg|thumb|left|19 Draconis in optical light]] '''19 Draconis''', also known as '''h Draconis''', is a [[star]] system in the [[constellation]] [[Draco (constellation)|Draco]]. It is visible to the naked eye as a faint, yellow-white hued star with an [[apparent visual magnitude]] of 4.89.<ref name=EgUBV/> Based on its [[stellar parallax|parallax]], the system is located about 49.8 [[light-year]]s (15.26 [[parsec]]s) away.<ref name=HIP/> It is moving closer to the Earth with a heliocentric [[radial velocity]] of −21&nbsp;km/s.<ref name=Gontcharov2006/>

This is a [[binary star]] system with an [[orbital period]] of 52.1&nbsp;days and an [[orbital eccentricity|eccentricity]] of 0.22. Only the primary star can be directly detected, via [[Doppler shift]]s or [[perturbation (astronomy)|perturbation]]s 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,<ref name=Abt/> 4% more massive than the [[Sun]]. Its surface temperature is about 6,298 [[Kelvin|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.<ref name=Wang/>

==Notes== {{reflist|group=note}}

==References== {{reflist}}

{{Stars of Draco}}

[[Category:F-type main-sequence stars]] [[Category:Solar-type stars]] [[Category:Spectroscopic binaries]] [[Category:Draco (constellation)]] [[Category:Bayer objects|Draconis, h]] [[Category:Durchmusterung objects]] [[Category:Flamsteed objects|Draconis, 19]] [[Category:Gliese and GJ objects|0648]] [[Category:Henry Draper Catalogue objects|153597]] [[Category:Hipparcos objects|082860]] [[Category:Bright Star Catalogue objects|6315]]