16 Delphini is a star in the equatorial constellation Delphinus. It has an apparent magnitude of 5.54,[2] making it faintly visible to the naked eye. The star is relatively close at a distance of 198 light years[1] but is receding with a poorly constrained radial velocity of 2 km/s.[5]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Delphinus |
| Right ascension | 20h 55m 38.5698s[1] |
| Declination | +12° 34′ 06.8774″[1] |
| Apparent magnitude (V) | 5.54±0.01[2] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | A5 V[4] |
| U−B color index | +0.09[2] |
| B−V color index | +0.11[2] |
| Astrometry | |
| Radial velocity (Rv) | 2.0±4.3[5] km/s |
| Proper motion (μ) | RA: +39.558 mas/yr[1] Dec.: +27.772 mas/yr[1] |
| Parallax (π) | 16.4866 ± 0.06 mas[1] |
| Distance | 197.8 ± 0.7 ly (60.7 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.63[6] |
| Details | |
| Mass | 2.0±0.1[7] M☉ |
| Radius | 1.9±0.1[8] R☉ |
| Luminosity | 18.7[6] L☉ |
| Surface gravity (log g) | 4.10±0.14[7] cgs |
| Temperature | 9,093±309[7] K |
| Metallicity [Fe/H] | −0.01[9] dex |
| Rotational velocity (v sin i) | 159[10] km/s |
| Age | 400+150 −215[7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
16 Delphini is a chemically peculiar A-type main-sequence star with a stellar classification of A5 V. It has twice the Sun's mass,[7] 1.9 times it's radius,[8] and shines at 18.7 L☉.[6] This yields an effective temperature of 9,039 K,[7] giving it a white glow. 16 Del is 400 million years old[7] – 56.5% through its main sequence lifetime[3] – and spins rapidly with a projected rotational velocity of 159 km/s.[10]
16 Del has a companion that was first discovered by John Herschel and was even noted to be a spectroscopic binary.[11] It is now considered to be a single star. [12]
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 c d Oja, T. (August 1991). "UBV photometry of stars whose positions are accurately known. VI". Astronomy and Astrophysics Supplement Series. 89: 415. Bibcode:1991A&AS...89..415O. ISSN 0365-0138.
- ^ a b Zorec, J.; Royer, F. (January 2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics. 537: A120. arXiv:1201.2052. Bibcode:2012A&A...537A.120Z. doi:10.1051/0004-6361/201117691. ISSN 0004-6361. S2CID 55586789.
- ^ Abt, Helmut A.; Morrell, Nidia I. (July 1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". The Astrophysical Journal Supplement Series. 99: 135. Bibcode:1995ApJS...99..135A. doi:10.1086/192182. ISSN 0067-0049.
- ^ a b Gontcharov, G. A. (November 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. ISSN 1063-7737. S2CID 119231169.
- ^ a b c 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 255204555.
- ^ a b c d e f g David, Trevor J.; Hillenbrand, Lynne A. (12 May 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. arXiv:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146. ISSN 0004-637X.
- ^ a b Allende Prieto, C.; Lambert, D. L. (December 1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555–562. arXiv:astro-ph/9911002. Bibcode:1999A&A...352..555A. ISSN 0004-6361.
- ^ Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters. 38 (12): 771–782. arXiv:1606.08814. Bibcode:2012AstL...38..771G. doi:10.1134/S1063773712120031. ISSN 0320-0108. S2CID 255201789.
- ^ a b Royer, F.; Zorec, J.; Gómez, A. E. (February 2007). "Rotational velocities of A-type stars: III. Velocity distributions". Astronomy & Astrophysics. 463 (2): 671–682. arXiv:astro-ph/0610785. Bibcode:2007A&A...463..671R. doi:10.1051/0004-6361:20065224. ISSN 0004-6361.
- ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. ISSN 0004-6256.
- ^ 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.