Nu Scorpii
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| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Scorpius |
| Right ascension | 16h 11m 59.7s |
| Declination | −19° 27' 39" |
| Apparent magnitude (V) | combined: +4.00 AB: 4.4 + 6.9 CD: 6.5 + 7.9 |
| Distance | 437 ± 65 ly (134 ± 20 pc) |
| Spectral type | AB: B2IV + B2IV CD: B8V + B9VpSi |
| Other designations | |
Jabbah, 14 Scorpii, 14 Sco, HR 6026 + HR 6027, HD 145501 + HD 145502, SAO 159763 + SAO 159764, HIP 79374, ADS 9951, CCDM 16120-1928, ν Sco, ν Scorpii, nu Sco, Nu Scorpii | |
Nu Scorpii (ν Sco, 14 Scorpii) also known as Jabbah[1][2] is a star system in the constellation Scorpius.
It is at least a quintuple star, probably a septuple,[3] consisting of two close groups that are separated by 41 arcseconds.
Since it is near the ecliptic, Nu Scorpii can be occulted by the Moon and, very rarely, by planets. Mercury occulted it on 14 December 1821, but will not occult it again until 2 December 2031. The last occultation by Venus took place on 27 December 1852 and the next will take place on 30 December 2095. On 29 July 1808 there was an occultation by Neptune.
Nu Scorpii is the star which causes the reflection nebula cataloged as IC 4592. Reflection nebulae are actually made up of very fine dust that normally appears dark but can look quite blue when reflecting the light of energetic nearby stars.
Nomenclature
Nu Scorpii bears the traditional name Jabbah.[1][2]
In Chinese astronomy, Nu Scorpii is called 鍵閉, Pinyin: Jiànbì, meaning Door Bolt, because this star is marking itself and stand alone in Door Bolt asterism, Room mansion (see : Chinese constellation).[4] 鍵閉 (Jiànbì), westernized into Keen Pi, but the name Keen Pi was designated for the formation of λ Sco (Shaula) and υ Sco (Lesath) by R.H. Allen and the meaning is "the Two Parts of a Lock." Instead Allen notes the name Jabbah, possibly from Iklīl al Jabhah.[2]
Multiplicity
| Aa | |||||||||||||||
| Aa/Ab | |||||||||||||||
| Ab | |||||||||||||||
| Aab/Ac | |||||||||||||||
| Ac | |||||||||||||||
| A/B | |||||||||||||||
| B | |||||||||||||||
| AB/CD | |||||||||||||||
| C | |||||||||||||||
| C/D | |||||||||||||||
| Da | |||||||||||||||
| Da/Db | |||||||||||||||
| Db | |||||||||||||||
Hierarchy of orbits in the nu Scorpii system
Nu Scorpii is a septuple star system.[3] It is one of only two known systems, the other being AR Cassiopeiae. Higher-multiplicity star systems are uncommon because they are less stable than their simpler counterparts, and often decay into smaller systems.
Nu Scorpii is split into two groups, Nu Scorpii AB and Nu Scorpii CD. Nu Scorpii CD is located 41 arcseconds away from Nu Scorpii A, and is also known as HR 6026.
Nu Scorpii A
Nu Scorpii A is the brightest member of the system. It has an apparent magnitude from 4.35, meaning that it can be seen with the naked eye. However, Nu Scorpii AB and CD cannot be resolved using the naked eye, but it can be resolved using a telescope.[5]
Nu Scorpii A is itself a triple star system. The main component of Nu Scorpii A is known as Nu Scorpii Aab, and it is a single-lined spectroscopic binary. Its components cannot be resolved but the stars' movements cause periodic Doppler shifts in their spectra. "Single-lined" means that light from only one of the stars can be detected. The pair has an orbital period of 5.5521 days and an eccentricity of 0.11, and an estimated separation of about 1.057 milliarcseconds.[6] The brighter component, Nu Scorpii Aa, has a spectral type of B3V implying a B-type main-sequence star. The fainter component, Nu Scorpii Ab, is thought to have an apparent magnitude of 6.90.[3]
Nu Scorpii Ac is the third component of the Nu Scorpii A subsystem. 63 milliarcseconds away, it has an apparent magnitude of 6.62.[3]
Other components
The brighter group, Nu Scorpii A and B, is split by 1.3" and composed of spectral type B2 subgiants. The fainter pair, Nu Scorpii C and D, are spectral type B8 and B9 main sequence dwarfs split by 2.4". Nu Scorpii A is itself a semi-detached spectroscopic binary, having a fainter B-type companion separated by approximately 0.3 mas.
References
- ^ a b Kaler, Jim. "Jabbah". Retrieved 2017-01-29.
- ^ a b c Allen, Richard Hinckley. "Star Names — Their Lore and Meaning: Scorpio". Retrieved 2017-01-29.
- ^ a b c d Nu Scorpii, entry in the Multiple Star Catalog
- ^ Template:Zh icon AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 8 日
- ^ "* nu. Sco". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 24 February 2017.
- ^ Levato, H.; Malaroda, S.; Morrell, N.; Solivella, G. (1987). "Stellar multiplicity in the Scorpius-Centaurus association". Astrophysical Journal Supplement Series. 64: 487–503. Bibcode:1987ApJS...64..487L. doi:10.1086/191204.
