Astronomy:16 Delphini

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Short description: Star in the constellation Delphinus
16 Delphini
Observation data
Epoch J2000.0   Equinox (celestial coordinates)
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[1] mas/yr
Dec.: +27.772[1] mas/yr
Parallax (π)16.4866 ± 0.06[1] mas
Distance197.8 ± 0.7 ly
(60.7 ± 0.2 pc)
Absolute magnitude (MV)+1.63[6]
Details
Mass2.0±0.1[7] M
Radius1.9±0.1[8] R
Luminosity18.7[6] L
Surface gravity (log g)4.10±0.14[7] cgs
Temperature9,093±309[7] K
Metallicity [Fe/H]−0.01[9] dex
Rotational velocity (v sin i)159[10] km/s
Age400+150−215[7] Myr
Other designations
Database references
SIMBADdata

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 km/s.[5]

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 solar luminosity.[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

  1. 1.0 1.1 1.2 1.3 1.4 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode2021A&A...649A...1G.  Gaia EDR3 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 Oja, T. (August 1991). "UBV photometry of stars whose positions are accurately known. VI.". Astronomy and Astrophysics Supplement Series 89: 415. ISSN 0365-0138. Bibcode1991A&AS...89..415O. 
  3. 3.0 3.1 Zorec, J.; Royer, F. (January 2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics 537: A120. doi:10.1051/0004-6361/201117691. ISSN 0004-6361. Bibcode2012A&A...537A.120Z. 
  4. 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. doi:10.1086/192182. ISSN 0067-0049. Bibcode1995ApJS...99..135A. 
  5. 5.0 5.1 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. doi:10.1134/S1063773706110065. ISSN 1063-7737. Bibcode2006AstL...32..759G. 
  6. 6.0 6.1 6.2 Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation" (in en). Astronomy Letters 38 (5): 331–346. doi:10.1134/S1063773712050015. ISSN 1063-7737. Bibcode2012AstL...38..331A. 
  7. 7.0 7.1 7.2 7.3 7.4 7.5 7.6 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. doi:10.1088/0004-637X/804/2/146. ISSN 0004-637X. Bibcode2015ApJ...804..146D. 
  8. 8.0 8.1 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. ISSN 0004-6361. Bibcode1999A&A...352..555A. 
  9. Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters 38 (12): 771–782. doi:10.1134/S1063773712120031. ISSN 0320-0108. Bibcode2012AstL...38..771G. 
  10. 10.0 10.1 Royer, F.; Zorec, J.; Gómez, A. E. (February 2007). "Rotational velocities of A-type stars: III. Velocity distributions". Astronomy & Astrophysics 463 (2): 671–682. doi:10.1051/0004-6361:20065224. ISSN 0004-6361. Bibcode2007A&A...463..671R. 
  11. 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. doi:10.1086/323920. ISSN 0004-6256. Bibcode2001AJ....122.3466M. 
  12. 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. Bibcode2008MNRAS.389..869E.