56 Ursae Majoris (56 UMa) is a star in the constellation Ursa Major. Its apparent magnitude is 5.03.[2] It is a single-lined spectroscopic binary with an orbital period of about 45 years.[5] The companion star is likely a heavy neutron star born by a supernova that exploded around 100,000 years ago.[6]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ursa Major |
| Right ascension | 11h 22m 49.58373s[1] |
| Declination | +43° 28′ 57.7267″[1] |
| Apparent magnitude (V) | 5.03[2] |
| Characteristics | |
| Spectral type | G7IIIBa0.3[3] |
| U−B color index | +0.82[4] |
| B−V color index | +1.02[4] |
| Astrometry | |
| Radial velocity (Rv) | 1.01 ± 0.05[5] km/s |
| Proper motion (μ) | RA: -37.42[1] mas/yr Dec.: -14.26[1] mas/yr |
| Parallax (π) | 6.12 ± 0.27 mas[1] |
| Distance | 530 ± 20 ly (163 ± 7 pc) |
| Orbit[6] | |
| Period (P) | 16911+438 −401 d |
| Semi-major axis (a) | 22.9+1.0 −1.1 au |
| Eccentricity (e) | 0.562+0.012 −0.012 |
| Inclination (i) | 68+3.6 −3.4° |
| Longitude of the node (Ω) | 60+3 −3° |
| Periastron epoch (T) | 2468401+432 −385 |
| Argument of periastron (ω) (secondary) | 286+2.3 −2.3° |
| Details[6] | |
| 56 UMa A | |
| Mass | 4.3 ± 0.2 M☉ |
| Surface gravity (log g) | 2.3 ± 0.6 cgs |
| Temperature | 4917 ± 34 K |
| 56 UMa B | |
| Mass | 1.31+0.11 −0.12 M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
References
edit- ^ a b c d e 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.
- ^ a b 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.
- ^ Lu, Phillip K. (1991). "Taxonomy of barium stars". Astronomical Journal. 101: 2229–2254. Bibcode:1991AJ....101.2229L. doi:10.1086/115845.
- ^ a b Fernie, J. D. (1983). "New UBVRI photometry for 900 supergiants". Astrophysical Journal Supplement Series. 52 (7–22): 7. Bibcode:1983ApJS...52....7F. doi:10.1086/190856.
- ^ a b Pourbaix, D.; et al. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727–732. arXiv:astro-ph/0406573. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213. S2CID 119387088.
- ^ a b c Escorza, A.; Karinkuzhi, D.; Jorissen, A.; Van Eck, S.; Schmelz, J. T.; Verschuur, G. L.; Boffin, H. M. J.; De Rosa, R. J.; Van Winckel, H. (2023). "A neutron star candidate in the long-period binary 56 UMa". Astronomy and Astrophysics. 670: L14. arXiv:2301.06531. Bibcode:2023A&A...670L..14E. doi:10.1051/0004-6361/202245796. S2CID 255941814.
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