Astronomy:Upsilon1 Cassiopeiae
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cassiopeia |
| Right ascension | 00h 55m 00.15523s[1] |
| Declination | +58° 58′ 21.7108″[1] |
| Apparent magnitude (V) | 4.82[2] |
| Characteristics | |
| Spectral type | K2 III[3] |
| U−B color index | +1.25[2] |
| B−V color index | +1.21[2] |
| Astrometry | |
| Radial velocity (Rv) | −23.57[4] km/s |
| Proper motion (μ) | RA: −33.50±0.36[1] mas/yr Dec.: −40.82±0.33[1] mas/yr |
| Parallax (π) | 9.93 ± 0.49[1] mas |
| Distance | 330 ± 20 ly (101 ± 5 pc) |
| Absolute magnitude (MV) | −0.644[4] |
| Details | |
| Mass | 1.39[5] M☉ |
| Radius | 21[6] R☉ |
| Luminosity | 174[5] L☉ |
| Surface gravity (log g) | 1.76[4] cgs |
| Temperature | 4,422±14[5] K |
| Metallicity [Fe/H] | −0.25[4] dex |
| Rotational velocity (v sin i) | 1.1[7] km/s |
| Age | 4.75[5] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Upsilon1 Cassiopeiae (υ1 Cassiopeiae) is an astrometric binary[9] star system in the northern constellation of Cassiopeia. It is visible to the naked eye with an apparent visual magnitude of 4.82.[2] Based upon an annual parallax shift of 9.93 mas as seen from Earth,[1] this system is located about 330 light years from the Sun.
The visible component is an evolved K-type giant star with a stellar classification of K2 III.[3] With an estimated age of 4.75 billion years,[5] it is a red clump star that is generating energy through the fusion of helium at its core.[10] The measured angular diameter, after correction for limb darkening, is 1.97±0.02 mas.[11] At the estimated distance of the star, this yields a physical size of about 21 times the radius of the Sun.[6] It has 1.39 times the mass of the Sun and is radiating 174 times the Sun's luminosity from its expanded photosphere at an effective temperature of 4,422 K.[5]
There is a magnitude 12.50 visual companion at an angular separation of 17.80 arc seconds along a position angle of 61°, as of 2003. A more distant magnitude 12.89 companion lies at a separation of 93.30 arc seconds along a position angle of 125°, as measured in 2003. Neither star appears to be physically associated with υ1 Cas.[12]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 2.3 Argue, A. N. (1966), "UBV photometry of 550 F, G and K type stars", Monthly Notices of the Royal Astronomical Society 133 (4): 475, doi:10.1093/mnras/133.4.475, Bibcode: 1966MNRAS.133..475A.
- ↑ 3.0 3.1 Eggen, O. J. (1962), "Space-velocity vectors for 3483 stars with proper motion and radial velocity", Royal Observatory Bulletin 51: 79, Bibcode: 1962RGOB...51...79E.
- ↑ 4.0 4.1 4.2 4.3 Soubiran, C. et al. (2008), "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants", Astronomy and Astrophysics 480 (1): 91–101, doi:10.1051/0004-6361:20078788, Bibcode: 2008A&A...480...91S.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 Luck, R. Earle (September 2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal 150 (3): 23, doi:10.1088/0004-6256/150/3/88, 88, Bibcode: 2015AJ....150...88L.
- ↑ 6.0 6.1 Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1, https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41. The radius (R*) is given by:
- [math]\displaystyle{ \begin{align} 2\cdot R_* & = \frac{(101\cdot 1.97\cdot 10^{-3})\ \text{AU}}{0.0046491\ \text{AU}/R_{\bigodot}} \\ & \approx 42.8\cdot R_{\bigodot} \end{align} }[/math]
- ↑ De Medeiros, J. R. et al. (November 2000), "Rotation and lithium in single giant stars", Astronomy and Astrophysics 363: 239–243, Bibcode: 2000A&A...363..239D.
- ↑ "ups01 Cas". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=ups01+Cas.
- ↑ 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Valentini, M.; Munari, U. (November 2010), "A spectroscopic survey of faint, high-Galactic-latitude red clump stars. I. The high resolution sample", Astronomy and Astrophysics 522: A79, doi:10.1051/0004-6361/201014870, Bibcode: 2010A&A...522A..79V, http://orbi.ulg.ac.be/jspui/handle/2268/142442.[yes|permanent dead link|dead link}}]
- ↑ Richichi, A. et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics 431 (2): 773–777, doi:10.1051/0004-6361:20042039, Bibcode: 2005A&A...431..773R.
- ↑ Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M.
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