27 Aquilae

In this article, we will deeply explore the fascinating world of 27 Aquilae. From its origins to its relevance today, we will immerse ourselves in a journey that will allow us to thoroughly understand its impact on different aspects of society. We will analyze its influence in fields as diverse as culture, economics and politics, unraveling its multiple facets and its role in shaping the contemporary world. Through a comprehensive analysis, we will explore the challenges and opportunities that 27 Aquilae represents, as well as possible implications for the future. At the end of this journey, we hope to have given our readers a deeper and more complete understanding of 27 Aquilae, opening new perspectives to reflect and debate its importance in today's world.

27 Aquilae
Location of 27 Aquilae (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Aquila
Right ascension 19h 20m 35.68321s[1]
Declination −00° 53′ 31.8067″[1]
Apparent magnitude (V) 5.49[2]
Characteristics
Spectral type B9 III[3]
U−B color index −0.23[2]
B−V color index −0.04[2]
Astrometry
Radial velocity (Rv)−27[4] km/s
Proper motion (μ) RA: 5.42[1] mas/yr
Dec.: 2.83[1] mas/yr
Parallax (π)7.45±0.28 mas[1]
Distance440 ± 20 ly
(134 ± 5 pc)
Absolute bolometric
magnitude (Mbol)		2.04–2.27[5]
Details
Surface gravity (log g)3.61 ± 0.50[6] cgs
Temperature11,500[6] K
Rotational velocity (v sin i)55[7] km/s
Other designations
BD−01°3716, GC 26673, HD 181440, HIP 95073, HR 7336, PPM 180629, SAO 143292[8]
Database references
SIMBADdata

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,[2] 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.[1] At this distance, the brightness of the star is diminished from extinction caused by interstellar gas and dust.[5]

The spectrum of 27 Aquilae fits a stellar classification of B9 III,[3] 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,[6] close observation have been made of its luminosity. The star shows a multiperiodic variability with at least six pulsation frequencies discovered.[9] It has a high rate of rotation with a projected rotational velocity of 55 km/s.[7] The outer atmosphere is radiating energy into space at an effective temperature of around 11,500 K,[6] giving it the blue-white hue of a B-type star.

References

  1. ^ a b c d e f 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. ^ a b c d 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. ^ a b 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. ^ a b 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. ^ a b c d 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. ^ a b 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.