Astronomy:Delta Phoenicis

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Short description: Star in the constellation Phoenix
δ Phoenicis
Phoenix constellation map.svg
Red circle.svg
Location of δ Phoenicis (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Phoenix
Right ascension  01h 31m 15.10475s[1]
Declination −49° 04′ 21.7308″[1]
Apparent magnitude (V) 3.93[2]
Characteristics
Spectral type G8.5 IIIb[2]
U−B color index +0.70[3]
B−V color index +0.99[3]
Astrometry
Radial velocity (Rv)−7.3±0.7[4] km/s
Proper motion (μ) RA: +138.38[1] mas/yr
Dec.: +153.89[1] mas/yr
Parallax (π)22.95 ± 0.19[1] mas
Distance142 ± 1 ly
(43.6 ± 0.4 pc)
Absolute magnitude (MV)0.73[2]
Details
Mass1.46[5] M
Radius10.5[6] R
Luminosity60.14[2] L
Surface gravity (log g)2.61[7] cgs
Temperature4,762±26[5] K
Metallicity [Fe/H]-0.28[7] dex
Rotational velocity (v sin i)< 1.0[8] km/s
Age3.69[5] Gyr
Other designations
Database references
SIMBADdata

Delta Phoenicis, Latinized from δ Phoenicis, is a single,[9] yellow-hued star in the southern constellation of Phoenix. With an apparent visual magnitude of 3.93,[2] it is visible to the naked eye. Based upon an annual parallax shift of 22.95 mas as seen from Earth,[1] it is located 142 light years from the Sun. The star is moving closer to the Sun with a radial velocity of −7 km/s.[4]

This is a G-type giant star with a stellar classification of G8.5 IIIb.[2] It is a red clump star, which means it has reached the stage of its evolution where it is generating energy through helium fusion at its core.[7] The measured angular diameter of this star, after correction for limb darkening, is 2.24±0.02 mas.[10] At its estimated distance, this yields a physical size of about 10.5 times the radius of the Sun.[6] It is around 3.7[5] billion years old with 1.46[5] times the mass of the Sun. The star is radiating 60[2] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,762 K.[5]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode2007A&A...474..653V.  Vizier catalog entry
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A.  Vizier catalog entry
  3. 3.0 3.1 Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers 42 (2): 443. Bibcode2014JAVSO..42..443M. Vizier catalog entry
  4. 4.0 4.1 Gontcharov, G. A. (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. Bibcode2006AstL...32..759G. 
  5. 5.0 5.1 5.2 5.3 5.4 5.5 Luck, R. Earle (2015). "Abundances in the Local Region. I. G and K Giants". Astronomical Journal 150 (3): 88. doi:10.1088/0004-6256/150/3/88. Bibcode2015AJ....150...88L. 
  6. 6.0 6.1 Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3rd ed.), Birkhäuser, ISBN 978-3-540-29692-8, https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41 . The radius (R*) is given by:
    [math]\displaystyle{ \begin{align} 2\cdot R_* & = \frac{(43.6\cdot 2.24 \cdot 10^{-3})\ \text{AU}}{0.0046491\ \text{AU}/R_{\bigodot}} \\ & \approx 21\cdot R_{\bigodot} \end{align} }[/math]
  7. 7.0 7.1 7.2 Liu, Y. J.; Zhao, G.; Shi, J. R.; Pietrzynski, G.; Gieren, W. (2007). "The abundances of nearby red clump giants". Monthly Notices of the Royal Astronomical Society 382 (2): 553. doi:10.1111/j.1365-2966.2007.11852.x. Bibcode2007MNRAS.382..553L. 
  8. De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (2014). "A catalog of rotational and radial velocities for evolved stars". Astronomy & Astrophysics 561: A126. doi:10.1051/0004-6361/201220762. Bibcode2014A&A...561A.126D.  Vizier catalog entry
  9. 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. 
  10. Richichi, A.; Percheron, I.; Khristoforova, M. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics 431 (2): 773–777, doi:10.1051/0004-6361:20042039, Bibcode2005A&A...431..773R.