θ Dra, 13 Her, BD+58°1608, FK5 598, HD 144284, HIP 78527, HR 5986, SAO 29765[11]
Database references
SIMBAD
data
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.[1] Parallax measurements place it at an estimated distance of 68.6 light-years (21.0 parsecs) from the Sun,[1] and it is drifting closer with a radial velocity of −8 km/s.[6] It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.464″ per year.[12] O. J. Eggen included this star as a member of the NGC 1901 supercluster based on its space motion.[13]
The binary nature of this system was discovered by W. W. Campbell in 1899, and the first set of orbital elements was published by H. D. Curtis in 1907.[14] It is a single-lined spectroscopic binary in a close orbit with a period of 3.07 days and an eccentricity (ovalness) of 0.04.[2] The secondary component has been resolved in the infrared H band, allowing an estimation of the mass ratio as 0.38±0.03.[8] Some velocity variation of K1 was observed by M. Mayor and T. Mazeh in 1987, which is suggestive of a tertiary component to the system.[15]
The primary component is a solar-type star[4] that at various times has been assigned stellar classifications of F9 V[2] and F8IV-V.[3] The star is about two billion years old and is spinning with a projected rotational velocity of 31 km/s.[7] It has a high metallicity (heavy element abundances) with around 20%[8] more mass than the Sun and nearly three[10] times the Sun's radius. The star displays no chromospheric emission and may be on or entering the subgiant stage. Because of the close orbit, it could be filling up to 60% of its Roche lobe.[16] The star is radiating ten times the luminosity of the Sun from its photosphere at an effective temperature of 6,105 K.[10]
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ThetaDraconis, a name Latinized from θ Draconis, is a binary star system in the northern circumpolar constellation of Draco. It is faintly visible to...
Eta Draconis (η Draconis, abbreviated Eta Dra, η Dra) is a binary star in the northern circumpolar constellation of Draco. Despite having an apparent visual...
Iota Draconis (ι Draconis, abbreviated Iota Dra, ι Dra), also named Edasich /ˈɛdəsɪk/, is a star in the northern circumpolar constellation of Draco. A...
Zeta Draconis (ζ Draconis, abbreviated Zet Dra, ζ Dra) is a binary star in the northern circumpolar constellation of Draco. With an apparent visual magnitude...
Star of Left Wall ThetaDraconis 上宰 Shǎng Zǎi The First Premier 紫微左垣三 Zǐ Wēi Zuǒ Yuán sān the Third Star of Left Wall Eta Draconis Athebyne 少宰 Shǎo Zǎi...
system 2.74 Eta Draconis Binary star system 2.75 Alpha2 Librae Binary star system 2.75 Beta Ophiuchi Star Maximum brightness 2.76 Theta Carinae Binary...
analyses with DAO spectrograms - XIX. The superficially normal B stars ζ Draconis, η Lyrae, 8 Cygni and 22 Cygni". Monthly Notices of the Royal Astronomical...
Chinese name Traditional Chinese 龍骨 Simplified Chinese 龙骨 Literal meaning dragon bones Japanese name Kanji 竜骨 Kana りゅうこつ Latin name Latin os draconis...
seen. It is located in the constellation of Scorpius, near the bright star Theta Scorpii. The star is in a crowded region of sky near the Galactic Center...
constellation Cassiopeia. This system shares the name Marfak /ˈmɑːrfæk/ with Theta Cassiopeiae, and the name was from Al Marfik or Al Mirfaq (المرفق), meaning...
near the boundary with Auriga, 49 arcminutes away from the bright star Theta Geminorum; due to its apparent magnitude of +9.89 it cannot be observed...
(2009-02-01). "Absolute properties of the low-mass eclipsing binary CM Draconis". The Astrophysical Journal. 691 (2): 1400–1411. arXiv:0810.1541. Bibcode:2009ApJ...