40 Aquarii is a star in the equatorial constellation of Aquarius. 40 Aquarii is its Flamsteed designation; it was too faint to be included in the Bright Star Catalogue.[9] The brightness of this star is below the normal limit for visibility with the naked eye, having an apparent visual magnitude of 6.93.[2] Based upon parallax measurements, it is located about 726 light-years (223 parsecs) away from the Sun.[1] It is moving closer to the Earth with a heliocentric radial velocity of -3 km/s.[5] 40 Aquarii is positioned near the ecliptic and thus is subject to lunar occultations.[10]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 22h 13m 26.37997s[1] |
| Declination | −11° 55′ 34.0405″[1] |
| Apparent magnitude (V) | 6.93[2] |
| Characteristics | |
| Spectral type | G5 IV[3] |
| B−V color index | +0.762±0.008[4] |
| Astrometry | |
| Radial velocity (Rv) | −2.9±0.3[5] km/s |
| Proper motion (μ) | RA: +20.95[6] mas/yr Dec.: −20.05[6] mas/yr |
| Parallax (π) | 4.4915 ± 0.0371 mas[1] |
| Distance | 726 ± 6 ly (223 ± 2 pc) |
| Absolute magnitude (MV) | −0.47[4] |
| Details[7] | |
| Radius | 10.07+0.44 −0.21[1] R☉ |
| Luminosity | 154.44[4] L☉ |
| Surface gravity (log g) | 2.69[7] cgs |
| Temperature | 5,355±80[7] K |
| Metallicity [Fe/H] | −0.13[7] dex |
| Age | 100[7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The stellar classification for 40 Aquarii is G5 IV,[3] matching a G-type, yellow-hued subgiant star that has exhausted the supply of hydrogen at its core and has begun to evolve into a giant. It is around 100[7] million years old with 10[1] times the girth of the Sun. The star is radiating 154[4] times the luminosity of the Sun from its photosphere at an effective temperature of 5,355 K.[7]
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. Gaia DR2 record for this source at VizieR.
- ^ a b Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H.
- ^ a b Houk, N.; Smith-Moore, M. (1988). "Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars. Volume 4, Declinations -26°.0 to -12°.0". Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars. 4. Bibcode:1988mcts.book.....H.
- ^ a b c d 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. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 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 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
- ^ a b c d e f g Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191, S2CID 118577511.
- ^ "* 40 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 7 August 2017.
- ^ Bidelman, W. P. (1990). "Flamsteed stars not contained in the Yale "Catalogue of Bright Stars"". Bulletin d'Information du Centre de Données Stellaires. 38: 13. Bibcode:1990BICDS..38...13B.
- ^ Boehme, D. (1978). "Derivation of Angular Diameters of Stars from Lunar Occultations". Astronomische Nachrichten. 299 (5): 243. Bibcode:1978AN....299..243B. doi:10.1002/asna.19782990505. See p. 256.