Английская Википедия:HD 178911

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Шаблон:Short description Шаблон:Starbox begin Шаблон:Starbox observe Шаблон:Starbox character Шаблон:Starbox character Шаблон:Starbox astrometry Шаблон:Starbox orbit Шаблон:Starbox detail |- ! colspan="2" style="text-align: center;" | HD 178911 B |- | Mass || Шаблон:Val[1] |- | Radius || Шаблон:Val[1] |- | Luminosity || Шаблон:Val[1] |- | Surface gravity (log g) || Шаблон:Val[1] |- | Temperature || Шаблон:Val[1] |- | Metallicity [Fe/H] || 0.23[2] |- | Rotational velocity (v sin i) || 4.6[2] |- | Age || Шаблон:Val[1] |- Шаблон:Starbox catalog Шаблон:Starbox reference Шаблон:Starbox end

HD 178911 is a triple star system with an exoplanetary companion in the northern constellation of Lyra. With a combined apparent visual magnitude of 6.70,[3] it is a challenge to view with the naked eye. The system is located at a distance of approximately 161 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −38 km/s.[4]

Stellar system

A companion star, designated component B, was first reported by F. G. W. Struve in 1823. As of 2019, the two have an angular separation of Шаблон:Val along a position angle of 263°.[5] Component B shares a common motion through space with the primary, and thus they form a wide binary.[6] This secondary is a magnitude 7.88[5] G-type main-sequence star with a stellar classification of G5V.[7] The physical properties of this star are similar to the Sun, although it has a higher metallicity.[1][2]

In 1985, the primary was determined to be a spectroscopic binary pair using the CHARA speckle interferometry program.[8] Designated components Aa and Ab, these have an orbital period of Шаблон:Cvt and an eccentricity (ovalness) of 0.6.[9] They are magnitude 6.89 and 8.96.[5] Based on based on a combined class of G5V for the pair,[10] they have derived main sequence stellar classifications of G1V and K1V, respectively.[9] C. D. Farrington and associates (2014) found dynamic masses for the components of 0.80 and 0.62, respectively.[9] However, based on the classes, the expected masses should be around 1.0 and 0.8. Manuel Andrade (2019) derived higher dynamic masses of 1.20 and 0.94.[10]

An additional companion HD 178911 C is a chance optical alignment and is not part of the system.[9]

Planetary system

In 2001 an extrasolar planet was discovered in orbit around HD 178911 B.[11][6]

Шаблон:OrbitboxPlanet begin Шаблон:OrbitboxPlanet Шаблон:Orbitbox end

See also

References

Шаблон:Reflist

External links

Шаблон:Sky Шаблон:Stars of Lyra

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  11. Ошибка цитирования Неверный тег <ref>; для сносок eso0114 не указан текст