Nu2 Coronae Borealis
 ν2 Coronae Borealis (lower red star) in optical light | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Corona Borealis |
| Right ascension | 16h 22m 29.21832s[1] |
| Declination | +33° 42′ 12.5247″[1] |
| Apparent magnitude (V) | +5.396[2] |
| Characteristics | |
| Evolutionary stage | RGB[3][1] |
| Spectral type | K5 III[4] |
| U−B color index | +1.787[2] |
| B−V color index | +1.525[2] |
| Astrometry | |
| Radial velocity (Rv) | −41.1±0.2[5] km/s |
| Proper motion (μ) | RA: −5.537[1] mas/yr Dec.: +49.931[1] mas/yr |
| Parallax (π) | 5.7163±0.0624 mas[1] |
| Distance | 571 ± 6 ly (175 ± 2 pc) |
| Absolute magnitude (MV) | −0.78[6] |
| Details | |
| Mass | 1.1[7] M☉ |
| Radius | 64[1] R☉ |
| Luminosity | 880[1] L☉ |
| Surface gravity (log g) | 1.76[8] cgs |
| Temperature | 3,940[8] K |
| Metallicity [Fe/H] | −0.16[8] dex |
| Rotational velocity (v sin i) | 3.1[9] km/s |
| Other designations | |
| ν2 Coronae Borealis, 21 CrB, BD+34 2774, HD 147767, HIP 80214, HR 6108, SAO 65259[10] | |
| Database references | |
| SIMBAD | data |
Nu2 Coronae Borealis is a solitary,[11] 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.[2] Based upon an annual parallax shift of 5.72 mas, it is located roughly 571 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction of 0.1 due to interstellar dust.[12]
This is an evolved red giant star with a stellar classification of K5 III.[4] The measured angular diameter of Nu2 Coronae Borealis is 2.53±0.16 mas.[13] At its estimated distance, this yields a physical size of about 64 times the radius of the Sun. Nu2 Coronae Borealis is radiating 880 times the Sun's luminosity from its photosphere at an effective temperature of 3,940 K.
The star ν1 Coronae Borealis lies 6′ borth of ν2. ν1 is also a red giant with almost the same apparent magnitude, but is a more luminous asymptotic giant branch star.[14]
References
[edit]- ^ a b c d e f g h Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d 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.
- ^ Gontcharov, G. A. (2011), "The red giant branch in the Tycho-2 catalogue", Astronomy Letters, 37 (10): 707, arXiv:1607.00557, Bibcode:2011AstL...37..707G, doi:10.1134/S1063773711090040.
- ^ a b 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.
- ^ 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.
- ^ 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.
- ^ Khalatyan, A.; Anders, F.; Chiappini, C.; Queiroz, A. B. A.; Nepal, S.; Dal Ponte, M.; Jordi, C.; Guiglion, G.; Valentini, M.; Torralba Elipe, G.; Steinmetz, M.; Pantaleoni-González, M.; Malhotra, S.; Jiménez-Arranz, Ó.; Enke, H.; Casamiquela, L.; Ardèvol, J. (2024), "Transferring spectroscopic stellar labels to 217 million Gaia DR3 XP stars with SHBoost", Astronomy and Astrophysics, 691: A98, arXiv:2407.06963, Bibcode:2024A&A...691A..98K, doi:10.1051/0004-6361/202451427.
- ^ a b c 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.
- ^ 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.
- ^ "nu02 CrB", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2017-08-25.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ Eggen, Olin J. (1992), "Asymptotic Giant Branch Stars Near the Sun", The Astronomical Journal, 104: 275, Bibcode:1992AJ....104..275E, doi:10.1086/116239.
