Delta Aquilae

Source: Wikipedia, the free encyclopedia.
Delta Aquilae
Location of δ Aquilae (circled) near the center
Observation data
J2000
Constellation Aquila
Right ascension 19h 25m 29.90139s[1]
Declination +03° 06′ 53.2061″[1]
Apparent magnitude (V) 3.365[2]
Characteristics
Spectral type F0 IV[3] + K[4]
U−B color index +0.031[2]
B−V color index +0.319[2]
R−I color index +0.16
Variable type δ Sct[5]
Distance
50.6 ± 0.8 ly
(15.5 ± 0.2 pc)
Absolute magnitude (MV)2.46[7]
Argument of periastron
(ω)
(secondary)		191 ± 14°
Details
δ Aql Aa
Rotational velocity (v sin i)
87.3[12] km/s
δ Aql Ab
Mass0.67[4] M☉
Radius0.61[4] R☉
NLTT 47775[13]
Database references
SIMBADdata

Delta Aquilae,

apparent visual magnitude of 3.4[2] and, based upon parallax measurements, is located at a distance of about 50.6 light-years (15.5 parsecs) from Earth.[1] It is drifting closer with a radial velocity of −30 km/s.[6] The system is predicted to come to within 25.4 ly (7.8 pc) of the Sun in around 335,000 years.[14]

Properties

γ Aquilae
.

The binary nature of this system was first reported by

gravitational perturbation
of the primary. The individual components have not been resolved with a telescope.

The primary member, designated component Aa, is an aging

projected rotational velocity of about 87 km s−1. This is a lower bound on the azimuthal velocity along the star's equator.[12]

The secondary, component Ab, is a smaller star with about 67% of the Sun's mass and an estimated 61% of the radius of the Sun.

K-type star.[4]

Naming

This star, along with

Jim Kaler has suggested the name Almizan Occidental.[17]

On the other hand, Antonín Bečvář includes, with no further explanation, Deneb Okab in his catalogue,[18] meaning the tail of eagle in Arabic; however, the star is situated in the centre of the constellation, which is usually identified with the chest, while the stars ε Aql and ζ Aql have been collectively known as Deneb al Okab by Arabian medieval astronomers,[15] which might suggest that Bečvář's assumption was a misnomer.

In the catalogue of stars in the Calendarium of Al Achsasi al Mouakket, this star was designated Djenubi Menkib al Nesr (منكب ألنسر ألخنوبي – mankib al-nasr al-janúbii), which was translated into Latin as Australior Humerus Vulturis, meaning the southern shoulder of the eagle.[19]

In

Chinese name for δ Aquilae itself is 右旗三 (Yòu Qí sān, English: the Third Star of Right Flag).[21]

This star, together with η Aql, θ Aql, ι Aql, κ Aql and λ Aql, were once part of the now-obsolete constellation Antinous.[22]

References

  1. ^
    S2CID 18759600
  2. ^
    Bibcode:1984SAAOC...8...59C
  3. ^
    doi:10.1086/129562
  4. ^
    doi:10.1111/j.1365-2966.2007.12671.x
  5. ^
    doi:10.1553/cia146s37
  6. ^
    Bibcode:1967IAUS...30...57E
  7. ^
    S2CID 8642707
  8. ^
    doi:10.1086/115169
  9. Bibcode:1990A&AS...85.1015M
  10. S2CID 1106754
  11. ^
    S2CID 118362423
  12. ^
    doi:10.1051/0004-6361:200810377
  13. Centre de Données astronomiques de Strasbourg
    , retrieved 2012-02-06
  14. S2CID 59039482
    , A35.
  15. ^
    ISBN 0-486-21079-0
    . Retrieved 2010-12-12.
  16. ^ Rhoads, Jack W. (November 15, 1971), Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars (PDF), Jet Propulsion Laboratory, California Institute of Technology, retrieved 2012-02-06
  17. ^ Kaler, Jim. "Delta Aql". Retrieved 2017-03-10.
  18. ^ Bečvář, A. (1951). Atlas Coeli Skalnaté Pleso II - Katalog 1950.0. Přírodovědecké Vydavatelstrí. p. 277. Retrieved 10 March 2017.
  19. doi:10.1093/mnras/55.8.429
  20. ISBN 978-986-7332-25-7
    .
  21. ^ (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表 Archived September 29, 2009, at the Wayback Machine, Hong Kong Space Museum. Accessed on line November 23, 2010.
  22. ^ Ian Ridpath's Star Tales - Antinous

External links

Retrieved from "https://en.wikipedia.org/w/index.php?title=Delta_Aquilae&oldid=1182987664"