YZ Cassiopeiae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cassiopeia |
| Right ascension | 00h 45m 39.0777s[1] |
| Declination | +74° 59′ 17.063″[1] |
| Apparent magnitude (V) | 5.6/6.0[2] |
| Characteristics | |
| Spectral type | A2IV[1] |
| B−V color index | 0.067[3] |
| Variable type | Algol variable |
| Astrometry | |
| Radial velocity (Rv) | +8.9±0.9[1] km/s |
| Proper motion (μ) | RA: -14.93[1] mas/yr Dec.: -21.86[1] mas/yr |
| Parallax (π) | 11.24 ± 0.55[1] mas |
| Distance | 290 ± 10 ly (89 ± 4 pc) |
| Orbit[1][4] | |
| Companion | TYC 4307-2168-1 |
| Period (P) | 86 580[4] yr |
| Other designations | |
YZ Cassiopeiae (21 Cas) is a star system 89 parsecs (290 light years) away from Earth, in the constellation Cassiopeia.[1] It comprises three stars: an eclipsing Algol-type binary and a visually fainter star about 3000 AU distant.[4]
The primary star in the YZ Cassiopeiae system is a white subgiant (main sequence) star of spectral type A1m[3] and 2.31 solar masses[4] (M☉) with a less massive main sequence dwarf star of type F2V[3] and 1.35 M☉.[4] The apparent magnitude of the eclipsing binary varies from 5.65 to 6.05[3] with a period of 4.4672 days.[4] Combined, they appear to have a spectral type of A2IV.[4]
The binary has a dimmer (magnitude 9.7 according to Norton,[2] or 10.5 by SIMBAD) companion of 0.8 M☉[4] orbiting with a period of about 86 580 years.[4]
References
- 1 2 3 4 5 6 7 8 9 10 "SIMBAD query result: V* YZ Cas -- Eclipsing binary of Algol type". Centre de Données astronomiques de Strasbourg. Retrieved 2008-09-05.
- 1 2 Norton, Arthur P. (1973). Norton's Star Atlas. p. 118. ISBN 0-85248-900-5.
- 1 2 3 4 Jerzy M. Kreiner, Chun-Hwey Kim, Il-Seong Nha. YZ CAS: Atlas of O-C Diagrams of Eclipsing Binary Stars
- 1 2 3 4 5 6 7 8 9 Tokovinin 1997-1999. J/A+AS/124/75. Multiple star catalogue (MSC)
Coordinates: 
00h 45m 39.0777s, +74° 59′ 17.063″
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