56 Aquilae

56 Aquilae

Observation data Epoch J2000      Equinox J2000
Constellation	Aquila
Right ascension	19^h 54^m 08.27613^s[1]
Declination	–08° 34′ 27.1674″[1]
Apparent magnitude (V)	5.79[2]
Characteristics
Spectral type	K5 III[3]
U−B color index	+2.00[2]
B−V color index	+1.664±0.006[4]
Astrometry
Radial velocity (Rv)	−49.5±2.9[5] km/s
Proper motion (μ)	RA: +6.737[1] mas/yr Dec.: –18.578[1] mas/yr
Parallax (π)	5.6650 ± 0.1739 mas[1]
Distance	580 ± 20 ly (177 ± 5 pc)
Absolute magnitude (MV)	−0.66[4]
Details
Radius	41.7+2.0 −2.6[1] R☉
Luminosity	391±14[1] L☉
Temperature	3,972+130 −91[1] K
Other designations
56 Aql, BD–08°5150, FK5 2131, GC 2343, HD 188154, HIP 97928, HR 7584, SAO 143894[6]
Database references
SIMBAD	data

56 Aquilae is a single^[7] star in the equatorial constellation of Aquila. 56 Aquilae is its Flamsteed designation. Its apparent visual magnitude is 5.79,^[2] meaning it is barely visible to the naked eye as a dim, orange-hued point of light, under ideal viewing conditions. The star is located at a distance of around 580 light years away from the Sun, based on parallax.^[1] It is moving closer to the Earth with a heliocentric radial velocity of −50 km/s,^[5] and is predicted to come as near as 222 light-years in around 3.3 million years.

This is an aging giant star with a stellar classification of K5 III,^[3] having exhausted the supply of hydrogen at its core and expanded to 42^[1] times the Sun's radius. It is radiating 391^[1] times the luminosity of the Sun from its photosphere at an effective temperature of 3,972 K.^[1] 56 Aquilae is a double star,^[8] but it does not appear to be a binary star system.^[7] It is one of the double stars profiled in Admiral William Henry Smyth's 1864 work, Sidereal Chromatics.

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
2. 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.
3. Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.
4. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
5. Wilson, Ralph Elmer (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W.
6. "56 Aql". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-01.
7. Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
8. James, Andrew, The application of Admiral Smyth's "Sidereal Chromatics", archived from the original on 2009-10-26, retrieved 2007-12-22.

External links

• [1]
• CCDM 19541-0834
• Image 56 Aquilae