39 Draconis

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39 Draconis
Observation data
Epoch J2000        Equinox J2000
Constellation Draco
Right ascension 18h 23m 54.60641s [1]
Declination +58° 48 02.6446 [1]
Apparent magnitude  (V)5.034 [2]
(5.06 + 8.07) [3]
Characteristics
Spectral type A1V + F5V [4]
U−B color index +0.06 [5]
B−V color index +0.10 [5]
Astrometry
Radial velocity (Rv)−24.53±0.23 [6]  km/s
Proper motion (μ)RA: −37.82 [1]   mas/yr
Dec.: +61.60 [1]   mas/yr
Parallax (π)17.71 ± 0.35  mas [1]
Distance 184 ± 4  ly
(56 ± 1  pc)
Absolute magnitude  (MV)1.31 / 4.32 [7]
Orbit [3]
Period (P)3962.50 ± 209.26 yr
Semi-major axis (a)6.621 ± 0.325″
Eccentricity (e)0.553 ± 0.005
Inclination (i)107.7 ± 0.12°
Longitude of the node (Ω)179.9 ± 0.10°
Periastron epoch (T)5671.40 ± 12.08
Argument of periastron (ω)
(secondary)
128.0 ± 2.18°
Details
39 Dra A
Mass 2.12 [7]   M
Radius 2.3 [8]   R
Surface gravity (log g)4.05 ± 0.07 [8]   cgs
Temperature 8710 [8]   K
39 Dra B
Mass 1.18 [7]   M
Other designations
b Dra, 39 Dra, BD+58°1809, HD  170073, HIP  90156, HR  6923, SAO  30949 [2]
Database references
SIMBAD 39 Dra
39 Dra A
39 Dra B

39 Draconis is a wide binary star system in the northern circumpolar constellation of Draco. It has the Bayer designation b Draconis, while 39 Draconis is the Flamsteed designation. This system is visible to the naked eye as a dim, white-hued point of light with an apparent visual magnitude of 5.0. [2] Parallax measurements made by the Hipparcos spacecraft put it at a distance of 184 light-years, or 56 parsecs away from the Sun. [1] The system is moving closer to the Earth with a heliocentric radial velocity of -24.5 km/s. [6]

The two components of 39 Draconis have an angular separation of 6.621 and take almost 4,000 years to orbit each other. [3] The primary star is an early A-type main-sequence star, having 2.12 times the mass of the Sun with a visual magnitude of 5.06 [3] The secondary is a magnitude 8.07 [3] F-type main-sequence star, and has 1.18 times the mass of the Sun. [7]

The 8th-magnitude star HD 238865 is listed in double star catalogues as component C. [9] It is separated from the other two stars by 90 and lies at about the same distance. [10] It is itself a spectroscopic binary with an F8 primary and a red dwarf secondary orbiting every 2.7 days. [11] [12]

Related Research Articles

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Mu Draconis is a multiple star system near the head of the constellation of Draco. With a combined magnitude of 4.92, it is visible to the naked eye. Based on parallax estimates by the Hipparcos spacecraft, it is located approximately 89 light-years from the Sun.

Xi Serpentis, Latinized from ξ Serpentis, is a triple star system in the Serpens Cauda (tail) section of the equatorial constellation Serpens. Based upon an annual parallax shift of 30.98 mas as seen from Earth, it is located 105.3 light years from the Sun. The star system is visible to the naked eye with a base apparent visual magnitude of +3.54. It is moving closer to the Sun and will make perihelion passage at a distance of 27 ly (8.2 pc) in around 690,000 years.

<span class="mw-page-title-main">Omega Ursae Majoris</span> Binary system in the constellation Ursa Major

Omega Ursae Majoris is the Bayer designation for a binary star system in the northern circumpolar constellation of Ursa Major. It is visible to the naked eye with an apparent visual magnitude of 4.61. Based upon an annual parallax shift of 13.24 mas, it is roughly 246 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.11 due to interstellar dust.

<span class="mw-page-title-main">Tau Ursae Majoris</span> Binary star in the constellation Ursa Major

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<span class="mw-page-title-main">Pi Virginis</span> Binary star in the constellation Virgo

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<span class="mw-page-title-main">14 Aurigae</span> Quadruple star system in the constellation Auriga

14 Aurigae is a quadruple star system located 269 light years away from the Sun in the zodiac constellation of Auriga. It has the variable star designation KW Aurigae, whereas 14 Aurigae is the Flamsteed designation. It is visible to the naked eye as a faint, white-hued star with a combined apparent visual magnitude of 5.01. The system is moving closer to the Sun with a heliocentric radial velocity of −9 km/s.

<span class="mw-page-title-main">31 Camelopardalis</span> Binary star system in the constellation Camelopardalis

31 Camelopardalis is a binary star system in the northern circumpolar constellation of Camelopardalis. It is visible to the naked eye as a dim point of light with a peak apparent visual magnitude of +5.12. Parallax measurements provide a distance estimate of approximately 460 light years away from the Sun, and the system is drifting closer to the Earth with a radial velocity of −3 km/s.

5 Tauri is a binary star in the zodiac constellation of Taurus, located approximately 530 light years from the Sun. It is visible to the naked eye as a faint orange-hued star with an apparent visual magnitude of +4.14. It is moving further from the Earth with a heliocentric radial velocity of +14 km/s.

δ Doradus is a star in the southern constellation of Dorado. Based upon an annual parallax shift of 21.80 mas as seen from Earth, it is located around 150 light years from the Sun. The star is visible to the naked eye with an apparent visual magnitude of +4.34.

<span class="mw-page-title-main">V538 Aurigae</span> Star in constellation Auriga

V538 Aurigae is a single star in the northern constellation of Auriga. With an apparent visual magnitude of 6.23, this star requires good dark sky conditions to view with the naked eye. It is located at a distance of 40.0 light-years (12.3 pc) from Sun based on parallax. The star is drifting further away with a radial velocity of 0.9 km/s. It is a member of the Local Association, and is most likely a thin disk star.

<span class="mw-page-title-main">Theta Draconis</span> Binary star system in the constellation Draco

Theta Draconis, a name Latinized from θ Draconis, is a binary star system in the northern circumpolar constellation of Draco. It is faintly visible to the naked eye at night with an apparent visual magnitude of 4.12. Parallax measurements place it at an estimated distance of 68.6 light-years from the Sun, and it is drifting closer with a radial velocity of −8 km/s. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.464″ per year. O. J. Eggen included this star as a member of the NGC 1901 supercluster based on its space motion.

<span class="mw-page-title-main">HR 7578</span> Binary star system in the constellation Sagittarius

HR 7578 is a binary star in the constellation of Sagittarius. Their combined apparent magnitude is 6.18. Parallax measurements by the Gaia spacecraft put the system at 46.01 light-years away, making this a nearby system.

<span class="mw-page-title-main">Chi Ceti</span> Double star in the constellation Cetus

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<span class="mw-page-title-main">1 Geminorum</span> Triple star system in the constellation Gemini

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Lambda Lupi, Latinized from λ Lupi, is a triple star system in the southern constellation of Lupus. It is visible to the naked eye with a combined apparent visual magnitude of 4.04. Based upon an annual parallax shift of just 4.20 mas as seen from Earth, it is located roughly 800 light years from the Sun. The system has a peculiar velocity of 27.4±4.9 km/s relative to its neighbors, making it a candidate runaway star system. It is a member of the Upper Centaurus–Lupus sub-group in the Scorpius–Centaurus OB association.

Mu Lupi is a system of three or four stars in the southern constellation of Lupus. It is visible to the naked eye with an apparent visual magnitude of 4.29 and lies roughly 340 light-years from the Sun.

Zeta<sup>1</sup> Lyrae Star in the constellation Lyra

Zeta1 Lyrae, Latinized from ζ1 Lyrae, is a binary star in the northern constellation of Lyra. Based upon an annual parallax shift of 20.89 mas as seen from Earth, the pair are located about 156 light years from the Sun. It is visible to the naked eye with an apparent visual magnitude of 4.37.

<span class="mw-page-title-main">Nu Leonis</span> Binary star system in the constellation Leo

ν Leonis, Latinised as Nu Leonis, is a binary star system in the zodiac constellation of Leo. It is faintly visible to the naked eye with an apparent visual magnitude of 5.15; parallax measurements indicate it is around 500 light years away. At this distance, the visual extinction from interstellar dust is 0.33 magnitudes.

c Ursae Majoris is the Bayer designation for a double-lined spectroscopic binary star system in the northern constellation of Ursa Major. It has an apparent visual magnitude of 5.18, which indicates that is visible to the naked eye. Parallax measurements yield an estimated distance of 66 light years from the Sun. The star is moving closer to the Earth with a heliocentric radial velocity of −14 km/s.

References

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