Delta Normae

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Delta Normae
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Norma
Right ascension 16h 06m 29.43692s[1]
Declination −45° 10′ 23.4518″[1]
Apparent magnitude (V) 4.74[2]
Characteristics
Spectral type kA3hA7mF0 III:[3]
U−B color index +0.16[2]
B−V color index +0.24[2]
Astrometry
Radial velocity (Rv) −15.5±2.8[4] km/s
Proper motion (μ) RA: −16.19[1] mas/yr
Dec.: −38.45[1] mas/yr
Parallax (π) 26.66 ± 0.74[1] mas
Distance 122 ± 3 ly
(38 ± 1 pc)
Details
Mass 1.75[5] M
Radius 2.00[5] R
Luminosity 13.4[6] L
Surface gravity (log g) 4.04[7] cgs
Temperature 7,691[7] K
Metallicity [Fe/H] +0.32[7] dex
Rotational velocity (v sin i) 7[5] km/s
Age 62.5±12.5[5] Myr
Other designations
δ Nor, CD−44° 10625, FK5 596, HD 144197, HIP 78914, HR 5980, SAO 226500[8]
Database references
SIMBAD data

Delta Normae (δ Normae) is a star system in the southern constellation of Norma. It is visible to the naked eye with an apparent visual magnitude of 4.74.[2] Based upon an annual parallax shift of 26.66 mas as seen from Earth,[1] the system is located about 122 light years distant from the Sun.

Because the proper motion of the star has been found to change over time, this is most likely an astrometric binary.[9][10] The visible component is an Am star, which means it displays the spectrum of a metal-lined A-type chemically peculiar star. The stellar classification of kA3hA7mF0 III:[3] indicates it is an evolved giant with the K-lines of an A3 class star, the hydrogen lines of an A7 star, and F0 class metallic lines. It has a magnetic field with an effective strength of (169.73±151.7)×10−4 T.[11]

Delta Normae has an estimated 1.75 times the mass of the Sun and twice the Sun's mass. It is around 63 million years old, and, as with other Am stars, has a relatively low spin rate with a projected rotational velocity of 7 km/s.[5] The star is radiating 13.4[6] times the Sun's luminosity from its photosphere at an effective temperature of 7,691 km/s.[7]

References[edit]

  1. ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752Freely accessible, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c d Feinstein, A. (1974), "Photoelectric UBVRI observations of Am stars", Astronomical Journal, 79: 1290, Bibcode:1974AJ.....79.1290F, doi:10.1086/111675. 
  3. ^ a b 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, Bibcode:2006AJ....132..161G, arXiv:astro-ph/0603770Freely accessible, doi:10.1086/504637. 
  4. ^ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, Bibcode:2012A&A...546A..61D, arXiv:1208.3048Freely accessible, doi:10.1051/0004-6361/201219219, A61. 
  5. ^ a b c d e Plavchan, Peter; et al. (June 2009), "New Debris Disks Around Young, Low-Mass Stars Discovered with the Spitzer Space Telescope", The Astrophysical Journal, 698 (2): 1068–1094, Bibcode:2009ApJ...698.1068P, arXiv:0904.0819Freely accessible, doi:10.1088/0004-637X/698/2/1068. 
  6. ^ a b McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, Bibcode:2012MNRAS.427..343M, arXiv:1208.2037Freely accessible, doi:10.1111/j.1365-2966.2012.21873.x. 
  7. ^ a b c d Soubiran, C.; et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics, 515: A111, Bibcode:2010A&A...515A.111S, arXiv:1004.1069Freely accessible, doi:10.1051/0004-6361/201014247. 
  8. ^ "del Nor". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-12. 
  9. ^ Frankowski, A.; et al. (March 2007), "Proper-motion binaries in the Hipparcos catalogue. Comparison with radial velocity data", Astronomy and Astrophysics, 464 (1): 377–392, Bibcode:2007A&A...464..377F, arXiv:astro-ph/0612449Freely accessible, doi:10.1051/0004-6361:20065526. 
  10. ^ 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, Bibcode:2008MNRAS.389..869E, arXiv:0806.2878Freely accessible, doi:10.1111/j.1365-2966.2008.13596.x. 
  11. ^ Bychkov, V. D.; et al. (April 2009), "Catalogue of averaged stellar effective magnetic fields - II. Re-discussion of chemically peculiar A and B stars", Monthly Notices of the Royal Astronomical Society, 394 (3): 1338–1350, Bibcode:2009MNRAS.394.1338B, doi:10.1111/j.1365-2966.2008.14227.x.