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Nu Coronae Borealis

ν Coronae Borealis (lower red star) in optical light
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Corona Borealis
Right ascension	16 22 29.21855
Declination	+33° 42′ 12.5274″
Apparent magnitude (V)	+5.396
Characteristics
Spectral type	K5 III
U−B color index	+1.787
B−V color index	+1.525
Astrometry
Radial velocity (Rv)	−41.1±0.2 km/s
Proper motion (μ)	RA: −5.42 mas/yr Dec.: +50.56 mas/yr
Parallax (π)	5.49 ± 0.24 mas
Distance	590 ± 30 ly (182 ± 8 pc)
Absolute magnitude (MV)	−0.78
Details
Radius	50 R☉
Luminosity	530 L☉
Surface gravity (log g)	1.76 cgs
Temperature	3,940 K
Metallicity	−0.16 dex
Rotational velocity (v sin i)	3.1 km/s
Other designations
ν Coronae Borealis, 21 CrB, BD+34 2774, HD 147767, HIP 80214, HR 6108, SAO 65259
Database references
SIMBAD	data

Nu Coronae Borealis is a solitary, orange-hued star located in the northern constellation of Corona Borealis. It is faintly visible to the naked eye, having an apparent visual magnitude of +5.4. Based upon an annual parallax shift of 5.49 mas, it is located roughly 590 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction of 0.1 due to interstellar dust.

This is an evolved red giant star with a stellar classification of K5 III. The measured angular diameter of Nu Coronae Borealis is 2.53±0.16 mas. At its estimated distance, this yields a physical size of about 50 times the radius of the Sun. Nu Coronae Borealis is radiating 530 times the Sun's luminosity from its photosphere at an effective temperature of 3,940 K.

References

1. ^ van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
2. ^ Jennens, P. A.; Helfer, H. L. (September 1975), "A new photometric metal abundance and luminosity calibration for field G and K giants", Monthly Notices of the Royal Astronomical Society, 172 (3): 667–679, Bibcode:1975MNRAS.172..667J, doi:10.1093/mnras/172.3.667.
3. ^ Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
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, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
5. Huang, W.; et al. (2012), "A catalogue of Paschen-line profiles in standard stars", Astronomy & Astrophysics, 547: A62, arXiv:1210.7893, Bibcode:2012A&A...547A..62H, doi:10.1051/0004-6361/201219804, S2CID 119286159.
6. ^ Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, vol. 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R_*) is given by:

   ${\displaystyle {\begin{aligned}2\cdot R_{*}&={\frac {(182\cdot 2.53\cdot 10^{-3})\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&\approx 99\cdot R_{\bigodot }\end{aligned}}}$

7. ^ McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
8. ^ McWilliam, Andrew (1990), "High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances", The Astrophysical Journal Supplement Series, 74: 1075, Bibcode:1990ApJS...74.1075M, doi:10.1086/191527.
9. De Medeiros, J. R.; et al. (November 2000), "Rotation and lithium in single giant stars", Astronomy and Astrophysics, 363: 239–243, arXiv:astro-ph/0010273, Bibcode:2000A&A...363..239D.
10. "nu02 CrB". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-25.{{cite web}}: CS1 maint: postscript (link)
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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
12. Famaey, B.; et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics, 430 (1): 165–186, arXiv:astro-ph/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272, S2CID 17804304.
13. Richichi, A.; et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.

• K-type giants
• Corona Borealis
• Bayer objects
• Durchmusterung objects
• Flamsteed objects
• Henry Draper Catalogue objects
• Hipparcos objects
• Bright Star Catalogue objects