Gamma Boötis
 γ Boötis (upper center) |
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| Observation data Epoch J2000 Equinox J2000 |
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|---|---|
| Constellation | Boötes |
| Right ascension | 14h 32m 04.6719s |
| Declination | +38° 18′ 29.709″ |
| Apparent magnitude (V) | 3.0 |
| Characteristics | |
| Spectral type | A7III |
| U−B color index | 0.12 |
| B−V color index | 0.19 |
| R−I color index | 0.08 |
| Variable type | Delta Scuti variable |
| Astrometry | |
| Radial velocity (Rv) | -36.5 km/s |
| Proper motion (μ) | RA: -115.55 mas/yr Dec.: 151.87 mas/yr |
| Parallax (π) | 38.29 ± 0.73 mas |
| Distance | 85 ± 2 ly (26.1 ± 0.5 pc) |
| Absolute magnitude (MV) | 3.23 |
| Details | |
| Mass | 3.1 M☉ |
| Radius | 2.1 R☉ |
| Luminosity | 40 L☉ |
| Temperature | 7,500–10,000 K |
| Rotational velocity (v sin i) | 139 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Data sources: | |
| Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.) |
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Gamma Boötis (γ Boo, γ Boötis) is a star in the constellation Boötes. It has the traditional name Seginus (also Segin, Ceginus) of uncertain origin. It was listed as Haris in Bečvář.
In Chinese astronomy, Seginus is called 招搖, Pinyin: Zhāoyáo, meaning Twinkling Indicator, because this star is marking itself and stand alone in Twinkling Indicator asterism, Root mansion (see : Chinese constellation).[1] 招搖 (Zhāoyáo), westernized into Chaou Yaou, but the name Chaou Yaou was designated for β Boötis (Nekkar) by R.H. Allen and the meaning is "to beckon, excite, or move." [2]
In the catalogue of stars in the Calendarium of Al Achsasi al Mouakket, this star was designated Menkib al Aoua al Aisr (منكب العواء الأيسر - mankibu lʿawwaaʾi lʾaysar), which was translated into Latin as Humerus Sinister Latratoris, meaning the left shoulder of barker.[3]
The name Seginus resulted from Latinization of an Arabic form of the Greek name of the constellation of Boötes (Theguius). The name Haris comes from the Arabic name of the constellation of Boötes, Al Haris Al Sama, which means "the guard".
[edit] Structure
Gamma Boötis is approximately 85 light years away from Earth. It belongs to the spectral class A7III. It is a Delta Scuti type variable star and its brightness varies from magnitude +3.02 to +3.07 with a period of 6.97 hours.
[edit] Namesakes
USS Seginus (AK-133) was a United States Navy Crater class cargo ship named after the star.
[edit] References
- ^ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 29 日
- ^ Richard Hinckley Allen: Star Names — Their Lore and Meaning: Boötes
- ^ Knobel, E. B. (June 1895). "Al Achsasi Al Mouakket, on a catalogue of stars in the Calendarium of Mohammad Al Achsasi Al Mouakket". Monthly Notices of the Royal Astronomical Society 55: 429. Bibcode 1895MNRAS..55..429K.
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