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27 Aquilae

Location of 27 Aquilae (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Aquila
Right ascension	19 20 35.68321
Declination	−00° 53′ 31.8067″
Apparent magnitude (V)	5.49
Characteristics
Spectral type	B9 III
U−B color index	−0.23
B−V color index	−0.04
Astrometry
Radial velocity (Rv)	−27 km/s
Proper motion (μ)	RA: 5.42 mas/yr Dec.: 2.83 mas/yr
Parallax (π)	7.45 ± 0.28 mas
Distance	440 ± 20 ly (134 ± 5 pc)
Absolute bolometric magnitude (Mbol)	2.04–2.27
Details
Surface gravity (log g)	3.61 ± 0.50 cgs
Temperature	11,500 K
Rotational velocity (v sin i)	55 km/s
Other designations
BD−01° 3716, GC 26673, HD 181440, HIP 95073, HR 7336, PPM 180629, SAO 143292.
Database references
SIMBAD	data

27 Aquilae (abbreviated 27 Aql) is a star in the equatorial constellation of Aquila. 27 Aquilae is its Flamsteed designation though it also bears the Bayer designation d Aquilae. It has an apparent visual magnitude of 5.49, which is faintly visible to the naked eye. Based upon parallax measurements made during the Hipparcos mission, this star is at a distance of 440 light-years (130 parsecs) from Earth, give or take a 20 light-year margin of error. At this distance, the brightness of the star is diminished from extinction caused by interstellar gas and dust.

The spectrum of 27 Aquilae fits a stellar classification of B9 III, with the luminosity class of III typically indicating this is an evolved giant star. As it lies within the field of view of the CoRoT satellite, close observation have been made of its luminosity. The star shows a multiperiodic variability with at least six pulsation frequencies discovered. It has a high rate of rotation with a projected rotational velocity of 55 km/s. The outer atmosphere is radiating energy into space at an effective temperature of around 11,500 K, giving it the blue-white hue of a B-type star.

References

1. ^ van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
2. ^ Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
3. ^ Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819.
4. Wilson, Ralph Elmer (1953), "General catalogue of stellar radial velocities", Carnegie Institute Washington D.C. Publication, Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W.
5. ^ van Belle, G. T.; et al. (PTI Collaboration) (May 2008), "The Palomar Testbed Interferometer Calibrator Catalog", The Astrophysical Journal Supplement Series, 176 (1): 276–292, arXiv:0711.4194, Bibcode:2008ApJS..176..276V, doi:10.1086/526548, S2CID 10713221.
6. ^ Lefever, K.; et al. (June 2010), "Spectroscopic determination of the fundamental parameters of 66 B-type stars in the field-of-view of the CoRoT satellite", Astronomy and Astrophysics, 515: A74, arXiv:0910.2851, Bibcode:2010A&A...515A..74L, doi:10.1051/0004-6361/200911956, S2CID 54028925.
7. ^ Abt, Helmut A.; Levato, Hugo; Grosso, Monica (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode:2002ApJ...573..359A, doi:10.1086/340590.
8. "d Aql". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-21.
9. Degroote, P.; et al. (December 2011), "CoRoT's view on variable B8/9 stars: spots versus pulsations. Evidence for differential rotation in HD 174648", Astronomy & Astrophysics, 536: A82, arXiv:1110.5601, Bibcode:2011A&A...536A..82D, doi:10.1051/0004-6361/201116802, S2CID 54570565.

v t e Constellation of Aquila
Aquila in Chinese astronomy Smith's Cloud List of stars in Aquila
Stars	Bayer α (Altair) β (Alshain) γ (Tarazed) δ ε ζ (Okab) η θ (Tseen Foo) ι κ λ μ ν ξ (Libertas) ο π σ τ υ φ χ ψ ω ω A b c d e f g h i k l Flamsteed 4 5 7 8 10 11 18 19 20 21 22 23 24 42 45 46 51 56 57 58 62 64 66 68 69 70 14 Sge 62 Ser 64 Sgr Variable R U V W TT FF QS V368 V450 V500 V603 V604 V605 V606 V923 V1286 V1291 V1298 V1302 V1315 V1333 V1339 V1427 V1428 V1429 V1472 V1487 V1494 V1654 V1672 V1691 V1703 (Phoenicia) V1828 V1936 HR 7099 7143 7288 7300 7307 7396 7456 7569 7598 7599 7693 7717 7803 HD 179079 183263 187734 192699 (Chechia) Other CoRoT-2 CoRoT-3 CoRoT-8 Gaia BH3 HAT-P-41 PSR J1856+0245 PSR J1903+0327 PSR B1913+16 (Hulse–Taylor) PSR J1951+1123 SGR 1900+14 SS 433 W43A W49-2 WASP-80 (Petra) WD J1953−1019 ZTF J1901+1458
Exoplanets CoRoT-2b CoRoT-3b CoRoT-8b CoRoT-10b HD 179079 b HD 183263 b c HD 192263 b HD 192699 b ξ Aquilae b
Star clusters NGC 6709 NGC 6738 NGC 6755 NGC 6756 NGC 6760
Nebulae	NGC 6741 6751 6778 6781 6790 Other Abell 48 Abell 70 E Nebula Hen 2-428 HESS J1857+026 W43 W49 W49B W50
Galaxies	NGC 6814 Other IC 1327
Category

• Aquila (constellation)
• B-type giants
• Bayer objects
• Flamsteed objects
• Henry Draper Catalogue objects
• Hipparcos objects
• Bright Star Catalogue objects
• Durchmusterung objects