Epoch J2000 Equinox J2000
|Right ascension||19h 51m 01.64400s|
|Declination||+10° 24′ 56.5992″|
|Apparent magnitude (V)||5.11|
|Spectral type||F8 V + M3 V|
|U−B color index||0.07|
|B−V color index||0.55|
|R−I color index||0.29|
|Radial velocity (Rv)||–0.2 km/s|
|Proper motion (μ)||RA: +242.28 mas/yr
Dec.: –136.48 mas/yr
|Parallax (π)||52.11 ± 0.29 mas|
|Distance||62.6 ± 0.3 ly
(19.2 ± 0.1 pc)
|Absolute magnitude (MV)||3.71|
|ο Aql A|
|Surface gravity (log g)||4.07 cgs|
|Metallicity [Fe/H]||+0.07 dex|
|Rotational velocity (v sin i)||3 km/s|
|ο Aql C|
Omicron Aquilae (ο Aql, ο Aquilae) is the Bayer designation for a double star in the equatorial constellation of Aquila. The brighter component has an apparent visual magnitude of +5.11, which means it is faintly visible to the naked eye in dark suburban skies. The annual parallax shift of this star is 52.11 mas, which is equivalent to a physical distance of 62.6 light-years (19.2 parsecs) from Earth.
The primary component, Omicron Aquilae A, is an F-type main sequence star with a stellar classification of F8 V. It has about 125% of the mass of the Sun and 152% of the Sun's radius. With an age of roughly 3.3 billion years, it appears to spinning at a leisurely rate with a projected rotational velocity of 3 km/s. The outer atmosphere has an effective temperature of 6,090 K, giving it the yellowish-white hue of an F-type star.
In 1998, Omicron Aquilae was one of nine stars identified as experiencing a superflare. The first flare observed from Omicron Aquilae was in 1979, with a magnitude increase of 0.07 and a duration of less than five days. The second occurred in 1980, with a magnitude change of 0.09 and a duration of fifteen days. The energy released during the second flare is estimated as 9 × 1037 erg.
There is a magnitude 12.67 common proper motion companion located at an angular separation of 22.5 arcseconds along a position angle of 221°. Based upon its matching parallax value, this corresponds to a projected separation of 431 astronomical units. (Hence, the companion is located at this separation or greater.) Designated component C, this is a small red dwarf star with a stellar classification of M3 V. Component B is an optical companion that appears near the primary only through a chance alignment.
- van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv: , doi:10.1051/0004-6361:20078357.
- Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49, Bibcode:1978A&AS...34....1N.
- Raghavan, Deepak; et al. (September 2010), "A Survey of Stellar Families: Multiplicity of Solar-type Stars", The Astrophysical Journal Supplement, 190 (1): 1–42, Bibcode:2010ApJS..190....1R, arXiv: , doi:10.1088/0067-0049/190/1/1.
- Takeda, Yoichi; et al. (February 2005), "High-Dispersion Spectra Collection of Nearby F--K Stars at Okayama Astrophysical Observatory: A Basis for Spectroscopic Abundance Standards", Publications of the Astronomical Society of Japan, 57 (1): 13–25, Bibcode:2005PASJ...57...13T, doi:10.1093/pasj/57.1.13.
- Holmberg, J.; Nordström, B.; Andersen, J. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, Bibcode:2009A&A...501..941H, arXiv: , doi:10.1051/0004-6361/200811191.
- Takeda, Genya; et al. (February 2007), "Structure and Evolution of Nearby Stars with Planets. II. Physical Properties of ~1000 Cool Stars from the SPOCS Catalog", The Astrophysical Journal Supplement Series, 168 (2): 297–318, Bibcode:2007ApJS..168..297T, arXiv: , doi:10.1086/509763.
- Frasca, A.; et al. (December 2009), "REM near-IR and optical photometric monitoring of pre-main sequence stars in Orion. Rotation periods and starspot parameters", Astronomy and Astrophysics, 508 (3): 1313–1330, Bibcode:2009A&A...508.1313F, doi:10.1051/0004-6361/200913327.
- Bonavita, M.; Desidera, S. (June 2007), "The frequency of planets in multiple systems", Astronomy and Astrophysics, 468 (2): 721–729, Bibcode:2007A&A...468..721B, arXiv: , doi:10.1051/0004-6361:20066671.
- "LTT 15798 -- High proper-motion Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-06-29.
- Schaefer, Bradley E.; King, Jeremy R.; Deliyannis, Constantine P. (February 2000), "Superflares on Ordinary Solar-Type Stars", The Astrophysical Journal, 529 (2): 1026–1030, Bibcode:2000ApJ...529.1026S, arXiv: , doi:10.1086/308325