70 Aquilae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 20h 36m 43.63394s[1] |
| Declination | −02° 32′ 59.8341″[1] |
| Apparent magnitude (V) | 4.903[2] |
| Characteristics | |
| Spectral type | K4+ III Ba1,[3] K3 III,[4] or K5 II[5] |
| B−V color index | 1.606±0.041[6] |
| Astrometry | |
| Radial velocity (Rv) | −9.4±0.4[7] km/s |
| Proper motion (μ) | RA: +10.124[1] mas/yr Dec.: –15.604[1] mas/yr |
| Parallax (π) | 3.4533 ± 0.3160 mas[1] |
| Distance | 940 ± 90 ly (290 ± 30 pc) |
| Absolute magnitude (MV) | −3.05[6] |
| Details | |
| Mass | 6.2±0.6[8] M☉ |
| Radius | 102[9] R☉ |
| Luminosity (bolometric) | 4,072[2] L☉ |
| Surface gravity (log g) | 1.9[10] cgs |
| Temperature | 3,900[2] K |
| Metallicity [Fe/H] | −0.294±0.093[11] dex |
| Rotational velocity (v sin i) | 1.9[10] km/s |
| Age | 63.1±17.8[8] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
70 Aquilae, abbreviated 70 Aql, is a single[13] orange-hued star in the equatorial constellation of Aquila. 70 Aquilae is its Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 4.90.[2] The distance to 70 Aquilae, as determined from its annual parallax shift of 3.5 mas,[1] is around 940 light years. The star is moving closer to the Earth with a heliocentric radial velocity of −9 km/s.[7]
Classification
[edit]Perkins et al. (1989) found a stellar classification of K4+ III Ba1[3] for this star, suggesting it is a K-type giant with abundance anomaly of barium.[14] Houk and Swift (1999) matched an ordinary giant with a class of K3 III.[4] Many sources[2][8][13][10][14] still use the 1991 Bright Star Catalogue classification of K5 II,[5] which instead suggests a bright giant star.
Size and temperature
[edit]The interferometry-measured angular diameter of this star, after correcting for limb darkening, is 3.27±0.04 mas,[15] which, at its estimated distance, equates to a physical radius of roughly 102 times the radius of the Sun.[9] 70 Aquilae is about 63 million years old with 6 times the mass of the Sun.[8] It is radiating 4,072[2] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,900 K.[2]
References
[edit]- ^ a b c d e f 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.
- ^ a b c d e f g Hohle, M. M.; et al. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants", Astronomische Nachrichten, 331 (4): 349, arXiv:1003.2335, Bibcode:2010AN....331..349H, doi:10.1002/asna.200911355, S2CID 111387483.
- ^ a b Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
- ^ a b Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.
- ^ a b Hoffleit, D.; Warren, Jr., W. H. (1991), "The Bright Star Catalogue", New Haven (5th Revised ed.), Astronomical Data Center, NSSDC/ADC, Bibcode:1964cbs..book.....H
- ^ a b 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.
- ^ a b Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
- ^ a b c d Tetzlaff, N.; et al. (2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
- ^ a b Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, vol. 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R*) is given by:
- ^ a b c Domiciano de Souza, A.; et al. (November 2005), "Gravitational-darkening of Altair from interferometry", Astronomy and Astrophysics, 442 (2): 567–578, Bibcode:2005A&A...442..567D, doi:10.1051/0004-6361:20042476.
- ^ Taylor, B. J. (February 1999), "Catalogs of temperatures and [Fe/H] averages for evolved G and K stars", Astronomy and Astrophysics Supplement, 134 (3): 523–524, Bibcode:1999A&AS..134..523T, doi:10.1051/aas:1999153.
- ^ "69 Aql". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved November 1, 2018.
- ^ a b Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ^ a b Gomez, A. E.; et al. (1997), "Absolute magnitudes and kinematics of barium stars", Astronomy and Astrophysics, 319: 881, Bibcode:1997A&A...319..881G.
- ^ Richichi, A.; et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.
