Astronomy:Mu Aquilae
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 34m 05.3529s[1] |
| Declination | +07° 22′ 44.189″[1] |
| Apparent magnitude (V) | 4.45[2] |
| Characteristics | |
| Spectral type | K3-IIIb Fe0.5[3] |
| U−B color index | +1.24[2] |
| B−V color index | +1.176[4] |
| R−I color index | 0.61 |
| Astrometry | |
| Radial velocity (Rv) | −24.73±0.13[5] km/s |
| Proper motion (μ) | RA: +213.73[1] mas/yr Dec.: −156.55[1] mas/yr |
| Parallax (π) | 30.31 ± 0.24[1] mas |
| Distance | 107.6 ± 0.9 ly (33.0 ± 0.3 pc) |
| Absolute magnitude (MV) | 1.80[5] |
| Details[6] | |
| Mass | 1.16±0.10 M☉ |
| Radius | 7.66±0.24 R☉ |
| Luminosity | 24.5 L☉ |
| Surface gravity (log g) | 2.70±0.06 cgs |
| Temperature | 4,567±79 K |
| Metallicity [Fe/H] | 0.16 dex |
| Rotational velocity (v sin i) | 0.0[4] km/s |
| Age | 6.71±2.19 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Mu Aquilae, Latinized from μ Aquilae, is the Bayer designation for a single[8] star in the equatorial constellation of Aquila. With an apparent visual magnitude of 4.45,[2] it is visible to the naked eye. The measured annual parallax shift of this star is 30.31 mas,[1] which gives a distance estimate of 107.6 light-years (33.0 parsecs) from Earth. It is drifting closer with a radial velocity of −25 km/s,[5] and displays a relatively high proper motion, traversing the celestial sphere at the rate of 0.264″ per year.[9]
The stellar classification of Mu Aquilae is K3-IIIb Fe0.5,[3] indicating that this is an evolved giant star with a mild overabundance of iron appearing in its spectrum. It belongs to a sub-category of giants called the red clump, which means it is generating energy through the fusion of helium at its core.[10] Compared to the Sun, it has 116% of the mass and has expanded to 7.7 times the size. This inflated outer envelope has an effective temperature of 4,567 K and is radiating 24.5 times the Sun's luminosity.[6] At this heat, Mu Aquilae glows with the orange hue of a K-type star.[11] It is roughly seven billion years old.[6]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 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.
- ↑ 3.0 3.1 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", The Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, Bibcode: 1989ApJS...71..245K.
- ↑ 4.0 4.1 Massarotti, Alessandro et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal 135 (1): 209–231, doi:10.1088/0004-6256/135/1/209, Bibcode: 2008AJ....135..209M.
- ↑ 5.0 5.1 5.2 Hekker, S. et al. (August 2006), "Precise radial velocities of giant stars. I. Stable stars", Astronomy and Astrophysics 454 (3): 943–949, doi:10.1051/0004-6361:20064946, Bibcode: 2006A&A...454..943H
- ↑ 6.0 6.1 6.2 Maldonado, J. et al. (June 2013), "The metallicity signature of evolved stars with planets", Astronomy & Astrophysics 554: 18, doi:10.1051/0004-6361/201321082, A84, Bibcode: 2013A&A...554A..84M.
- ↑ "* mu. Aql". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+mu.+Aql.
- ↑ Eggleton, Peter; Tokovinin, A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Lépine, Sébastien; Shara, Michael M. (March 2005), "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)", The Astronomical Journal 129 (3): 1483–1522, doi:10.1086/427854, Bibcode: 2005AJ....129.1483L.
- ↑ Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal 539 (2): 732–741, doi:10.1086/309278, Bibcode: 2000ApJ...539..732A.
- ↑ "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, retrieved 2012-01-16.
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