17 Delphini is a solitary[11] star in the equatorial constellation Delphinus. It has an absolute magnitude of −0.64[7] and apparent magnitude of 5.18,[2] allowing it to be faintly seen with the naked eye. Located 517 light years away,[1] it is approaching the Solar System with a heliocentric radial velocity of −10.2 km/s.[6]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Delphinus |
| Right ascension | 20h 55m 36.689s[1] |
| Declination | +13° 43′ 17.531″[1] |
| Apparent magnitude (V) | 5.18[2](5.16-5.27)[3] |
| Characteristics | |
| Spectral type | K0 III[4] |
| U−B color index | +0.95[5] |
| B−V color index | +1.13[5] |
| Variable type | suspected[3] |
| Astrometry | |
| Radial velocity (Rv) | −10.2±0.9[6] km/s |
| Proper motion (μ) | RA: +16.457 mas/yr[1] Dec.: −11.468 mas/yr[1] |
| Parallax (π) | 6.3132 ± 0.0699 mas[1] |
| Distance | 517 ± 6 ly (158 ± 2 pc) |
| Absolute magnitude (MV) | −0.64[7] |
| Details[8] | |
| Mass | 2.33 M☉ |
| Radius | 23.36 R☉ |
| Luminosity | 219 L☉ |
| Surface gravity (log g) | 2.07 cgs |
| Temperature | 4,616 K |
| Metallicity [Fe/H] | −0.19[9] dex |
| Rotational velocity (v sin i) | 3±1[10] km/s |
| Age | 832 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
17 Delphini is an orange giant that is most likely on the horizontal branch (84% probability).[8] At present it has 2.33 times the mass of the Sun, but at an age of 832 million years — has expanded to 23.36 times the radius of the Sun.[8] It shines at 219 solar luminosities from its enlarged photosphere at an effective temperature of 4,616 K,[8] giving it an orange glow. 17 Del has an iron abundance 64% that of the Sun[9] and spins modestly with a projected rotational velocity of 3 km/s.[10]
17 Del is suspected to be a variable star of unknown type ranging from 5.16 to 5.27.[3]
References
edit- ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
- ^ a b Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.
- ^ a b c Samus’, N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (January 2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. ISSN 1063-7729. S2CID 255195566.
- ^ Griffin, R. F.; Redman, R. O. (1 April 1960). "Photoelectric Measurements of the 4200 A CN Band and the G Band in G8-K5 Spectra". Monthly Notices of the Royal Astronomical Society. 120 (4): 287–316. Bibcode:1960MNRAS.120..287G. doi:10.1093/mnras/120.4.287.
- ^ a b Gutierrez-Moreno, A. (1966). "A system of photometric standards". Publications of the Department of Astronomy University of Chile. 1: 1. Bibcode:1966PDAUC...1....1G.
- ^ a b Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Carnegie Institute Washington D.C. Publication: 0. Bibcode:1953GCRV..C......0W.
- ^ a b Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. ISSN 1063-7737. S2CID 119257644.
- ^ a b c d Stock, Stephan; Reffert, Sabine; Quirrenbach, Andreas (August 2018). "Precise radial velocities of giant stars: X. Bayesian stellar parameters and evolutionary stages for 372 giant stars from the Lick planet search". Astronomy & Astrophysics. 616: A33. arXiv:1805.04094. Bibcode:2018A&A...616A..33S. doi:10.1051/0004-6361/201833111. ISSN 0004-6361.
- ^ a b Hekker, S.; Meléndez, J. (December 2007). "Precise radial velocities of giant stars: III. Spectroscopic stellar parameters". Astronomy & Astrophysics. 475 (3): 1003–1009. arXiv:0709.1145. Bibcode:2007A&A...475.1003H. doi:10.1051/0004-6361:20078233. ISSN 0004-6361.
- ^ a b de Medeiros, J. R.; Mayor, M. (November 1999). "A catalog of rotational and radial velocities for evolved stars". Astronomy and Astrophysics Supplement Series. 139 (3): 433–460. Bibcode:1999A&AS..139..433D. doi:10.1051/aas:1999401. ISSN 0365-0138.
- ^ 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. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.