Location of WZ Doradus on the map (circled) | |
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Dorado |
Right ascension | 05h07m 34.02686s[1] |
Declination | −63° 23′ 58.8474″[1] |
Apparent magnitude (V) | 5.20 - 5.32[2] |
Characteristics | |
Evolutionary stage | AGB[3] |
Spectral type | M3 III[4] |
U−B color index | +1.85[5] |
B−V color index | +1.65[5] |
Variable type | SRb[2] |
Astrometry | |
Radial velocity (Rv) | 19.3±2.8[6] km/s |
Proper motion (μ) | RA: +13.210 mas/yr[1] Dec.: −44.813 mas/yr[1] |
Parallax (π) | 5.6282 ± 0.1116 mas[1] |
Distance | 580 ± 10 ly (178 ± 4 pc) |
Absolute magnitude (MV) | −1.00[7] |
Details | |
Mass | 1.4[8] M☉ |
Radius | 88.3+6.6 −10.0[9] R☉ |
Luminosity | 1,248±47[9] L☉ |
Surface gravity (log g) | 0.50[10] cgs |
Temperature | 3,603±125[10] K |
Other designations | |
21 G. Doradus[11], WZ Dor, CD−63°188, CPD−63°420, FK5 2389, GC 6314, HD 33684, HIP 23840, HR 1695, SAO 249198, TIC 55298910[12] | |
Database references | |
SIMBAD | data |
WZ Doradus (HD 33684; HR 1695; 21 G. Doradus) is a solitary red-hued variable star[13] located in the southern constellation Dorado. It has an average apparent magnitude of 5.21,[14] making it faintly visible to the naked eye under ideal conditions. Gaia DR3 parallax measurements imply a distance of 580 light-years[1] and it is currently receding with a heliocentric radial velocityof19.3 km/s.[6] At its current distance, WZ Doradus is diminished by two-tenths of a magnitude due to interstellar extinction and it has an absolute magnitude of −1.00.[7]
HD 33684 was first observed to vary in brightness by astronomer P. M. Corben in 1971.[15] It was said to have an amplitude of 0.18 magnitudes. A year later, HD 33684 was given the variable star designation WZ Doradus.[16] It was again observed in 1973 by Olin J. Eggen and he noticed that it varied within 40 days.[17] A 1998 survey found no strong emissions indicating dust around the star.[18] Another survey also found no technetium in its spectrum.[19] WZ Doradus is a semiregular variable of subtype SRb that varies between 5.2 and 5.32 within an average period of 40 days.[2] Tabur et al. (2009) found two periods for the star after it was widely believed to only have one period.[20]
Amplitude (mag) | Period (days) |
---|---|
0.042 | 26.0 |
0.026 | 44.6 |
WZ Doradus has a stellar classification of M3 III,[4] indicating that it is an evolved red giant. It is currently on the asymptotic giant branch,[3] generating energy via the fusion of hydrogen and helium shells around an inert carbon core. As a result of its evolved state, it has expanded to 88.3 times the radius of the Sun[9] and it now radiates 1,248 times the luminosity of the Sun[9] from its enlarged photosphere at an effective temperatureof3,603 K.[10]