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| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cassiopeia |
| Right ascension | 00h01m 15.85680s[1] |
| Declination | +60° 21′ 19.0259″[1] |
| Apparent magnitude (V) | 7.04[2] (6.3 – 8.8)[3] |
| Characteristics | |
| Spectral type | C-N7 III: C2 2 Li 10[4] |
| U−B color index | +4.29[5] |
| B−V color index | +2.835±0.040[2] |
| Variable type | SRb[3] |
| Astrometry | |
| Radial velocity (Rv) | −34.0±2[6] km/s |
| Proper motion (μ) | RA: +10.7693[1] mas/yr Dec.: −5.672[1] mas/yr |
| Parallax (π) | 2.1227 ± 0.0297 mas[1] |
| Distance | 1,540 ± 20 ly (471 ± 7 pc) |
| Details | |
| Radius | ~600[7] R☉ |
| Luminosity | 12,400[8] L☉ |
| Temperature | 3,095[8] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
WZ Cassiopeiae (WZ Cas) is a deep red hued star in the northern constellationofCassiopeia. It is a variable star with a magnitude that ranges from 6.3 down to 8.8,[3] placing it near the limit of naked eye visibility at peak magnitude. The estimated distance to this star, as determined from its annual parallax shiftof2.1 mas,[1] is about 1,540 light years. It is moving closer to the Earth with a heliocentric radial velocity of −34 km/s.[6]
This is an aging carbon star on the asymptotic giant branch.[7] Keenan (1993) assigned it a classificationofC-N7 III: C2 2 Li 10, which indicates it is of the N star subtype in the revised Morgan–Keenan system, with a C2 strength index of 2 (a measure of the excess of carbon over oxygen) and an anomalously strong line of lithium at 6707 Å.[4] It is losing mass at the rate of 6.5×10−9 M☉yr−1, which is on the low side for a star of this type. This is a semiregular variable of subtype SRb[3] with periods of 186 and 366 days due to radial pulsations.[7] It has expanded to around 600 times the Sun's radius and is radiating 12,400 times the Sun's luminosity[8] from its photosphere at a relatively cool[10] effective temperature of 3,095 K.[8]
A magnitude 8.4 B-type visual companion, designated HD 224869, is located at an angular separationof58″. The difference in the radial velocities for the two stars – 20 km/s – is too large for them to be dynamically associated.[11]
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