Astronomy:16 Vulpeculae
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Vulpecula |
| Right ascension | 20h 02m 01.43152s[1] |
| Declination | +24° 56′ 16.9534″[1] |
| Apparent magnitude (V) | 5.787[2] 5.93 + 6.22[3] |
| Characteristics | |
| Spectral type | F2 III[4] |
| U−B color index | +0.10[5] |
| B−V color index | +0.37[5] |
| Astrometry | |
| Radial velocity (Rv) | −37.00±3.7[6] km/s |
| Proper motion (μ) | RA: 89.31[1] mas/yr Dec.: 69.44[1] mas/yr |
| Parallax (π) | 14.71 ± 0.50[1] mas |
| Distance | 222 ± 8 ly (68 ± 2 pc) |
| Absolute magnitude (MV) | 2.47[7] |
| Orbit[8] | |
| Period (P) | 1201 yr |
| Semi-major axis (a) | 2.687″ |
| Eccentricity (e) | 0.932 |
| Inclination (i) | 79.0° |
| Longitude of the node (Ω) | 84.5° |
| Periastron epoch (T) | B 1863.7 |
| Argument of periastron (ω) (secondary) | 276.5° |
| Details | |
| 16 Vul A | |
| Mass | 1.34[9] M☉ |
| Luminosity | 31.13[10] L☉ |
| Surface gravity (log g) | 3.76±0.14[9] cgs |
| Temperature | 6,888±234[9] K |
| Metallicity [Fe/H] | 0.17[11] dex |
| Rotational velocity (v sin i) | 136.1±6.8[7] km/s |
| Age | 742[9] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
16 Vulpeculae is a binary star system in the northern constellation Vulpecula.[1] It has a combined apparent visual magnitude of 5.787,[2] which is near the lower limit of visibility to the naked eye. Based upon an annual parallax shift of 14.71±0.50[1] as seen from Earth's orbit, it is located about 222 light years away. The system is moving closer to the Sun with a heliocentric radial velocity of about −37 km/s.[6] It will make its closest approach in about 0.9 million years, coming within 155 light-years (47.42 pc).[10]
The pair orbit each other with an estimated period of 1,201 years and an orbital eccentricity of 0.932.[8] The magnitude 5.93 primary, component A, displays a stellar classification of F2III,[12] matching an aging F-type giant star. This star is spinning rapidly with a projected rotational velocity of 136 km/s.[7] This is giving the star an oblate shape with an equatorial bulge that is an estimated 21% larger than the polar radius.[13] It is 742[9] million years old with 1.34[9] times the mass of the Sun. The star is radiating 31[10] times the Sun's luminosity from its photosphere at an effective temperature of about 6,888 K.[9]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 van Leeuwen, F. (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 Høg, E. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. Bibcode: 2000A&A...355L..27H.
- ↑ 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Cowley, Anne; Fraquelli, Dorothy (1974), "MK Spectral Types for Some Bright F Stars", Publications of the Astronomical Society of the Pacific 86 (509): 70, doi:10.1086/129562, Bibcode: 1974PASP...86...70C
- ↑ 5.0 5.1 Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode: 1986EgUBV........0M.
- ↑ 6.0 6.1 Holmberg, J. et al. (2007), "The Geneva-Copenhagen survey of the Solar neighbourhood. II. New uvby calibrations and rediscussion of stellar ages, the G dwarf problem, age-metallicity diagram, and heating mechanisms of the disk", Astronomy & Astrophysics 475 (2): 519–537, doi:10.1051/0004-6361:20077221, Bibcode: 2007A&A...475..519H.
- ↑ 7.0 7.1 7.2 Ammler-von Eiff, Matthias; Reiners, Ansgar (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics 542: A116, doi:10.1051/0004-6361/201118724, Bibcode: 2012A&A...542A.116A.
- ↑ 8.0 8.1 "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6. Retrieved 24 August 2017.
- ↑ 9.0 9.1 9.2 9.3 9.4 9.5 9.6 David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal 804 (2): 146, doi:10.1088/0004-637X/804/2/146, Bibcode: 2015ApJ...804..146D.
- ↑ 10.0 10.1 10.2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ Casagrande, L. et al. (2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy & Astrophysics 530 (A138): 21, doi:10.1051/0004-6361/201016276, Bibcode: 2011A&A...530A.138C.
- ↑ 12.0 12.1 "* 16 Vul". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+16+Vul.
- ↑ Belle, G. T. (2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review 20 (1): 51, doi:10.1007/s00159-012-0051-2, Bibcode: 2012A&ARv..20...51V.
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