27 Aquilae
  | |
| Observation data EpochJ2000.0EquinoxJ2000.0(ICRS) | |
|---|---|
| Constellation | Aquila |
| Right ascension | 19h20m35.68321s[1] |
| Declination | −00° 53′ 31.8067″[1] |
| Apparent magnitude(V) | 5.49[2] |
| Characteristics | |
| Spectral type | B9 III[3] |
| U−Bcolor index | −0.23[2] |
| B−Vcolor 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 ± 0.28mas[1] |
| Distance | 440 ± 20ly (134 ± 5pc) |
| Absolute bolometric magnitude(Mbol) | 2.04–2.27[5] |
| Details | |
| Surface gravity(logg) | 3.61 ± 0.50[6]cgs |
| Temperature | 11,500[6]K |
| Rotational velocity(vsini) | 55[7]km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
27 Aquilae(abbreviated27 Aql) is astarin theequatorialconstellationofAquila.27 Aquilaeis itsFlamsteed designationthough it also bears theBayer designationd Aquilae.It has anapparent visual magnitudeof 5.49,[2]which is faintly visible to the naked eye. Based uponparallaxmeasurements made during theHipparcosmission, this star is at a distance of 440light-years(130parsecs) from Earth, give or take a 20 light-yearmargin of error.[1]At this distance, the brightness of the star is diminished fromextinctioncaused by interstellar gas and dust.[5]
Thespectrumof 27 Aquilae fits astellar classificationof B9 III,[3]with theluminosity classof III typically indicating this is anevolvedgiant star.As it lies within the field of view of theCoRoTsatellite,[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 aprojected rotational velocityof 55 km/s.[7]Theouter atmosphereis radiating energy into space at aneffective temperatureof around 11,500 K,[6]giving it the blue-white hue of aB-type star.
References
[edit]- ^abcdefvan 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,S2CID18759600.
- ^abcdJohnson, 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.
- ^abCowley, 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.
- ^Wilson, Ralph Elmer (1953), "General catalogue of stellar radial velocities",Carnegie Institute Washington D.C. Publication,Carnegie Institution of Washington,Bibcode:1953GCRV..C......0W.
- ^abvan 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,S2CID10713221.
- ^abcdLefever, 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,S2CID54028925.
- ^abAbt, 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.
- ^"d Aql".SIMBAD.Centre de données astronomiques de Strasbourg.Retrieved2012-07-21.
- ^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,S2CID54570565.
