Iota Cassiopeiae
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Cassiopeia |
ι Cas A | |
Right ascension | 02h 29m 03.960s[1] |
Declination | +67° 24′ 08.70″[1] |
Apparent magnitude (V) | 4.61[1](4.65 / 8.48)[2] |
ι Cas B | |
Right ascension | 02h 29m 03.567s[1] |
Declination | +67° 24′ 07.01″[1] |
Apparent magnitude (V) | 6.87[1] |
ι Cas C | |
Right ascension | 02h 29m 05.086s[1] |
Declination | +67° 24′ 05.53″[1] |
Apparent magnitude (V) | 9.05[3](9.14 / 11.84)[3] |
Characteristics | |
U−B color index | +0.03[4] |
B−V color index | +0.12[4] |
ι Cas A | |
Spectral type | A3p / G6[2] |
Variable type | α2 CVn[5] |
ι Cas B | |
Spectral type | F5[2] |
ι Cas C | |
Spectral type | K4 / M2[3] |
U−B color index | +0.18[4] |
B−V color index | +0.72[4] |
Astrometry | |
Radial velocity (Rv) | 1.2 ± 2[6] km/s |
Proper motion (μ) | RA: -26.61[7] mas/yr Dec.: 38.21[7] mas/yr |
Parallax (π) | 24.55 ± 0.81 mas[7] |
Distance | 133 ± 4 ly (41 ± 1 pc) |
Absolute magnitude (MV) | 1.62 ± 0.07 (Aa) 5.60 ± 0.17 (Ab)[8] |
Orbit[8] | |
Primary | ι Cas Aa |
Companion | ι Cas Ab |
Period (P) | 50.2 ± 1.0 yr |
Semi-major axis (a) | 0.429 ± 0.007″ |
Eccentricity (e) | 0.642 ± 0.009 |
Inclination (i) | 149.0+1.7 −1.6° |
Longitude of the node (Ω) | 180.0+2.7 −2.8° |
Periastron epoch (T) | B 1993.24 ± 0.08 |
Argument of periastron (ω) (secondary) | 331.3+2.6 −2.7° |
Orbit[9] | |
Primary | ι Cas A |
Companion | ι Cas B |
Period (P) | 620 yr |
Semi-major axis (a) | 2.88″ |
Eccentricity (e) | 0.75 |
Inclination (i) | 115° |
Longitude of the node (Ω) | 0.8° |
Periastron epoch (T) | B 1640 |
Argument of periastron (ω) (secondary) | 283° |
Details | |
ι Cas Aa | |
Mass | 1.99 ± 0.28[2] M☉ |
Radius | 2.3 ± 0.4[10] R☉ |
Luminosity | 24[10] L☉ |
Temperature | 8360 ± 275[10] K |
Rotation | 1.74033 d[10] |
Rotational velocity (v sin i) | 48[10] km/s |
Age | 100[8] Myr |
ι Cas Ab | |
Mass | 0.69 ± 0.12[2] M☉ |
ι Cas B | |
Mass | 1.4[9] M☉ |
Temperature | 6540[3] K |
ι Cas Ca | |
Temperature | 4520 ± 20[3] K |
ι Cas Cb | |
Temperature | 3590 ± 45[3] K |
Other designations | |
ι Cas A: TYC 4058-1504-1 | |
ι Cas B: TYC 4058-1504-2 | |
ι Cas C: TYC 4058-1505-1 | |
Database references | |
SIMBAD | ι Cas |
ι Cas AB | |
ι Cas A | |
ι Cas B | |
ι Cas C |
Iota Cassiopeiae (ι Cas, ι Cassiopeiae) is a star system in the constellation Cassiopeia. The system has a combined apparent magnitude of 4.53,[11] making it visible to the naked eye. Based on its parallax, it is located about 133 light-years (41 parsecs) from Earth.[7]
Components
Iota Cassiopeiae is known to be a quintuple star system. The brightest star system, ι Cassiopeiae A, contains a white-colored A-type main-sequence star with a mean apparent magnitude of +4.61.[1] The primary component is a tighter binary star system itself. The two stars themselves were resolved by adaptive optics, revealing two stars. These are designated Aa and Ab (although confusingly they may also be labeled as A and Aa, respectively). The primary is classified as an Alpha2 Canum Venaticorum-type variable star and the brightness of the system varies from magnitude +4.45 to +4.53 with a period of 1.74 days,[5] because of its magnetic field.[10] The fainter companion is a G-type star with a mass of only 0.69 M☉.[2] The orbital period of the system is about 50 years.[8]
A second component, ι Cassiopeiae B, is a yellow-white F-type main sequence dwarf with an apparent magnitude of +6.87.[1] The semimajor axis of its orbit is 2.88 arcseconds, and it has an orbital period of 620 years around ι Cassiopeiae A.[9]
The third astrometric component, ι Cassiopeiae C, is another binary like ι Cassiopeiae A. It comprises two stars, a K-type star and a M-type star.[3] It orbits at an angular distance of 7 arcseconds from the A-B primary.[12]
References
- ^ a b c d e f g h i j Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H.
- ^ a b c d e f Drummond, Jack; Milster, Scott; Ryan, Patrick; Roberts, Jr., Lewis C. (2003). "ι Cassiopeiae: Orbit, Masses, and Photometry from Adaptive Optics Imaging in the I and H Bands". The Astrophysical Journal. 585 (2): 1007. Bibcode:2003ApJ...585.1007D. doi:10.1086/346224.
- ^ a b c d e f g Christou, Julian C.; Drummond, Jack D. (2006). "Measurements of Binary Stars, Including Two New Discoveries, with the Lick Observatory Adaptive Optics System". The Astronomical Journal. 131 (6): 3100. Bibcode:2006AJ....131.3100C. doi:10.1086/503255.
- ^ a b c d Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
- ^ a b Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....1.2025S.
- ^ Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Washington. Bibcode:1953GCRV..C......0W.
- ^ a b c d van Leeuwen, F.; et al. (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 c d De Rosa, R. J.; Patience, J.; Vigan, A.; Wilson, P. A.; Schneider, A.; McConnell, N. J.; Wiktorowicz, S. J.; Marois, C.; Song, I.; MacIntosh, B.; Graham, J. R.; Bessell, M. S.; Doyon, R.; Lai, O. (2012). "The Volume-limited A-Star (VAST) survey - II. Orbital motion monitoring of A-type star multiples". Monthly Notices of the Royal Astronomical Society. 422 (4): 2765. arXiv:1112.3666. Bibcode:2012MNRAS.422.2765D. doi:10.1111/j.1365-2966.2011.20397.x. S2CID 102487103.
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: CS1 maint: unflagged free DOI (link) - ^ a b c Heintz, W. D. (1996). "A Study of Multiple-Star Systems". The Astronomical Journal. 111: 408. Bibcode:1996AJ....111..408H. doi:10.1086/117792.
- ^ a b c d e f Aurière, M.; Wade, G. A.; Silvester, J.; Lignières, F.; Bagnulo, S.; Bale, K.; Dintrans, B.; Donati, J. F.; Folsom, C. P.; Gruberbauer, M.; Hui Bon Hoa, A.; Jeffers, S.; Johnson, N.; Landstreet, J. D.; Lèbre, A.; Lueftinger, T.; Marsden, S.; Mouillet, D.; Naseri, S.; Paletou, F.; Petit, P.; Power, J.; Rincon, F.; Strasser, S.; Toqué, N. (2007). "Weak magnetic fields in Ap/Bp stars". Astronomy and Astrophysics. 475 (3): 1053. arXiv:0710.1554. Bibcode:2007A&A...475.1053A. doi:10.1051/0004-6361:20078189. S2CID 54850596.
- ^ "* iot Cas". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 15 May 2017.
- ^ Tokovinin, A. A. (1997). "MSC - a catalogue of physical multiple stars". Astronomy and Astrophysics Supplement Series. 124: 75–84. Bibcode:1997A&AS..124...75T. doi:10.1051/aas:1997181. (HR 707[permanent dead link])
- Alpha2 Canum Venaticorum variables
- Bayer objects
- Cassiopeia (constellation)
- Multiple star systems
- Spectroscopic binaries
- A-type main-sequence stars
- F-type main-sequence stars
- G-type main-sequence stars
- HR objects
- Henry Draper Catalogue objects
- Hipparcos objects
- Durchmusterung objects
- Ap stars
- Variable star stubs
- Multiple star stubs