Astronomy:66 Aquilae
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Aquila |
| Right ascension | 20h 13m 13.87230s[1] |
| Declination | −01° 00′ 33.7724″[1] |
| Apparent magnitude (V) | 5.44[2] |
| Characteristics | |
| Spectral type | K5 III[3] |
| B−V color index | 1.430±0.001[2] |
| Astrometry | |
| Radial velocity (Rv) | −30.1±1.7[4] km/s |
| Proper motion (μ) | RA: +32.872[1] mas/yr Dec.: –15.851[1] mas/yr |
| Parallax (π) | 4.4436 ± 0.3133[1] mas |
| Distance | 730 ± 50 ly (230 ± 20 pc) |
| Absolute magnitude (MV) | −1.20[2] |
| Details | |
| Radius | 59[5] R☉ |
| Luminosity | 634.65[2] L☉ |
| Surface gravity (log g) | 1.84[6] cgs |
| Temperature | 4040[6] K |
| Metallicity [Fe/H] | −0.20[6] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
66 Aquilae, abbreviated 66 Aql, is a fifth-magnitude star in the constellation of Aquila. 66 Aquilae is its Flamsteed designation. It is visible to the naked eye, having an apparent visual magnitude of 5.44.[2] The star shows an annual parallax shift of 4.4 mas,[1] which provides a distance estimate of around 730 light years. It is moving closer to the Earth with a heliocentric radial velocity of −30 km/s.[4] The motion of the star over time suggests some displacement, which may indicate it is a close binary system.[8]
This is an aging giant star with a stellar classification of K5 III,[3] which indicates it has exhausted the supply of hydrogen at its core and expanded off the main sequence. The measured angular diameter of this star, after correcting for limb darkening, is 2.44±0.03 mas.[9] At its estimated distance, this yields a physical size of roughly 59 times the radius of the Sun.[5] It is radiating 635[2] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,040 K,[6] giving the star an orange hue. This star was part of the obsolete constellation Anguilla.
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey 5, Bibcode: 1999MSS...C05....0H.
- ↑ 4.0 4.1 Gontcharov, G. A. (2006), "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode: 2006AstL...32..759G.
- ↑ 5.0 5.1 Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1, https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41. The radius (R*) is given by:
- [math]\displaystyle{ \begin{align} 2\cdot R_* & = \frac{(10^{-3}\cdot 225\cdot 2.44)\ \text{AU}}{0.0046491\ \text{AU}/R_{\bigodot}} \\ & \approx 118\cdot R_{\bigodot} \end{align} }[/math]
- ↑ 6.0 6.1 6.2 6.3 McWilliam, Andrew (December 1990), "High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances", Astrophysical Journal Supplement Series 74: 1075–1128, doi:10.1086/191527, Bibcode: 1990ApJS...74.1075M.
- ↑ "66 Aql". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=66+Aql.
- ↑ Mason, Brian D.; Martin, Christian; Hartkopf, William I.; Barry, Donald J.; Germain, Marvin E.; Douglass, Geoffrey G.; Worley, Charles E.; Wycoff, Gary L. et al. (1999), "Speckle Interferometry of New and Problem HIPPARCOS Binaries", The Astronomical Journal 117 (4): 1890, doi:10.1086/300823, Bibcode: 1999AJ....117.1890M
- ↑ Richichi, A. et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics 431 (2): 773–777, doi:10.1051/0004-6361:20042039, Bibcode: 2005A&A...431..773R
 |  |
