Astronomy:Delta Leporis

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Short description: Star in the constellation Lepus
Delta Leporis
Observation data
Equinox J2000.0]] (ICRS)
Constellation Lepus
Right ascension  05h 51m 19.29613s[1]
Declination −20° 52′ 44.7232″[1]
Apparent magnitude (V) 3.85[2]
Characteristics
Spectral type K1 IV Fe−0.5[3] or K0 IIIb Fe−1.5 CH0.5[4]
U−B color index +0.71[2]
B−V color index +0.98[2]
Astrometry
Radial velocity (Rv)+100.20[5] km/s
Proper motion (μ) RA: +229.49[1] mas/yr
Dec.: −648.41[1] mas/yr
Parallax (π)28.68 ± 0.17[1] mas
Distance113.7 ± 0.7 ly
(34.9 ± 0.2 pc)
Absolute magnitude (MV)+1.04[6]
Details
Mass0.94[6] M
Radius10[7] R
Luminosity45.7[6] L
Surface gravity (log g)2.46±0.23[8] cgs
Temperature4,660±84[8] K
Metallicity [Fe/H]−0.74±0.09[8] dex
Rotational velocity (v sin i)0[9] km/s
Age10.7[6] Gyr
Other designations
 Lep, 15 Lep, BD−20° 1211, FK5 222, GC 7362, HD 39364, HIP 27654, HR 2035, SAO 170926, LHS 1792[10]
Database references
SIMBADdata

Delta Leporis (δ Leporis) is a solitary,[11] orange-hued star in the southern constellation of Lepus. It is visible to the naked eye with an apparent visual magnitude of 3.85.[2] Based upon an annual parallax shift of 28.68 mas,[1] it is 114 light years distant from Earth.

This is an old, evolved K-type star with an age of about 10.7 billion years.[6] Keenan and McNeil (1989) classified it as K0 IIIb Fe−1.5 CH0.5,[4] indicating it is a giant star showing a deficiency of iron and an excess of cyanogen in its atmosphere. However, Gray et al. (2006) listed it as K1 IV Fe−0.5,[3] which would suggest a less evolved subgiant star. It may be a red clump star, which indicates it is generating energy through helium fusion at its core.[12]

The measured angular diameter of this star, after correction for limb darkening, is 2.63±0.04 mas.[13] At the estimated distance of this star, this yields a physical size of about 10 times the radius of the Sun.[7] It has only 94%[6] of the Sun's mass and is radiating 46[6] times the Sun's luminosity from its photosphere at an effective temperature of 4,660 K.[8]

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. 
  2. 2.0 2.1 2.2 2.3 Ducati, J. R. (2002), "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system", CDS/ADC Collection of Electronic Catalogues 2237, Bibcode2002yCat.2237....0D. 
  3. 3.0 3.1 Gray, R. O. et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal 132 (1): 161–170, doi:10.1086/504637, Bibcode2006AJ....132..161G. 
  4. 4.0 4.1 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, Bibcode1989ApJS...71..245K. 
  5. 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, Bibcode2006AstL...32..759G. 
  6. 6.0 6.1 6.2 6.3 6.4 6.5 6.6 Takeda, Yoichi et al. (August 2008), "Stellar Parameters and Elemental Abundances of Late-G Giants", Publications of the Astronomical Society of Japan 60 (4): 781–802, doi:10.1093/pasj/60.4.781, Bibcode2008PASJ...60..781T. 
  7. 7.0 7.1 Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1, https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41.  The radius (R*) is given by:
    [math]\displaystyle{ \begin{align} 2\cdot R_* & = \frac{(34.9\cdot 2.63\cdot 10^{-3})\ \text{AU}}{0.0046491\ \text{AU}/R_{\bigodot}} \\ & \approx 19.7\cdot R_{\bigodot} \end{align} }[/math]
  8. 8.0 8.1 8.2 8.3 Sharma, Kaushal et al. (2016), "New atmospheric parameters and spectral interpolator for the MILES cool stars", Astronomy & Astrophysics 585: 27, doi:10.1051/0004-6361/201526111, A64, Bibcode2016A&A...585A..64S. 
  9. Uesugi, Akira; Fukuda, Ichiro (1970), "Catalogue of rotational velocities of the stars", Contributions from the Institute of Astrophysics and Kwasan Observatory (University of Kyoto), Bibcode1970crvs.book.....U. 
  10. "del Lep". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=del+Lep. 
  11. 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. 
  12. Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal 539 (2): 732–741, doi:10.1086/309278, Bibcode2000ApJ...539..732A. 
  13. Richichi, A. et al. (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.