Nu¹ Coronae Borealis

Nu¹ Coronae Borealis is a solitary,[7] red-hued star located in the northern constellation of Corona Borealis. It is faintly visible to the naked eye, having an apparent visual magnitude of 5.20.[2] Based upon an annual parallax shift of 5.0 mas,[8] it is located roughly 650 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction of 0.1 due to interstellar dust.[9] This object is drifting closer with a radial velocity of −13 km/s.[4]

For other stars with this Bayer designation, see ν Coronae Borealis.

Nu¹ Coronae Borealis

ν^1 Coronae Borealis (upper red star) in optical light
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Corona Borealis
Right ascension	16^h 22^m 21.42545^s[1]
Declination	+33° 47′ 56.5825″[1]
Apparent magnitude (V)	5.20[2]
Characteristics
Spectral type	M2 III[3]
B−V color index	1.64[3]
Astrometry
Radial velocity (Rv)	−13.17±0.35[4] km/s
Proper motion (μ)	RA: +4.265[1] mas/yr Dec.: −37.877[1] mas/yr
Parallax (π)	5.0069 ± 0.1323[1] mas
Distance	650 ± 20 ly (200 ± 5 pc)
Absolute magnitude (MV)	−1.19[3]
Details
Radius	67.1±7.1[5] R☉
Luminosity	975±30[1] L☉
Temperature	3,936+565 −295[1] K
Other designations
ν^1 Coronae Borealis, 20 CrB, BD+34 2773, HD 147749, HIP 80197, HR 6107, SAO 65257[6]
Database references
SIMBAD	data

This is an evolved red giant star with a stellar classification of M2 III.[3] It is a variable star of uncertain type, showing a change in brightness with an amplitude of 0.0114 magnitude and a frequency of 0.22675 cycles per day, or 4.41 days/cycle.[10] It has about 67[5] times the Sun's radius and is radiating 975 times the Sun's luminosity from its photosphere at an effective temperature of 3,936 K.[1]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
2. 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, Bibcode:2002yCat.2237....0D.
3. 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.
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, A61.
5. Dyck, H. M.; Benson, J. A.; Van Belle, G. T.; Ridgway, S. T. (1996), "Radii and Effective Temperatures for K and M Giants and Supergiants", The Astronomical Journal, 111 (1): 521–533, Bibcode:1996AJ....111.1705D, doi:10.1086/117910.
6. "nu01 CrB". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-26.
7. 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.
8. 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.
9. 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.
10. Koen, Chris; Eyer, Laurent (2002), "New periodic variables from the Hipparcos epoch photometry", Monthly Notices of the Royal Astronomical Society, 331: 45, arXiv:astro-ph/0112194, Bibcode:2002MNRAS.331...45K, doi:10.1046/j.1365-8711.2002.05150.x.