WOH G64
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Dorado |
| Right ascension | 04h 55m 10.5252s |
| Declination | −68° 20′ 29.998″ |
| Apparent magnitude (V) | 17.7–18.8 |
| Characteristics | |
| A | |
| Evolutionary stage | OH/IR extreme red supergiant or red hypergiant |
| Spectral type | M5I–M7.5e |
| Apparent magnitude (K) | 6.849 |
| Apparent magnitude (R) | 15.69 |
| Apparent magnitude (G) | 15.0971 |
| Apparent magnitude (I) | 12.795 |
| Apparent magnitude (J) | 9.252 |
| Apparent magnitude (H) | 7.745 |
| Variable type | Slow irregular variable + symbiotic |
| B | |
| Spectral type | B |
| Astrometry | |
| Radial velocity (Rv) | 285±2 km/s |
| Proper motion (μ) | RA: +1.689 mas/yr Dec.: −0.013 mas/yr |
| Distance | 163,000 ly (50,000 pc) |
| Absolute magnitude (MV) | −6.00 |
| Details | |
| A | |
| Mass | ~20 M☉ |
| Radius | 1,540±77 R☉ |
| Luminosity | 282,000+34,400 −30,700 L☉ |
| Surface gravity (log g) | −0.5±0.1 cgs |
| Temperature | 3,400±25 K |
| Age | ≤5 Myr |
| Other designations | |
| LI-LMC 181, MSX LMC 1182, IRAS 04553–6825, 2MASS J04551048−6820298 | |
| Database references | |
| SIMBAD | data |
WOH G64 (IRAS 04553–6825) is a symbiotic binary in the Large Magellanic Cloud, roughly 50 kiloparsecs (163,000 light-years) from Earth.
The primary component is an extreme red supergiant or red hypergiant that may be the largest known star with a well-defined radius, calculated to be around 1,540 times that of the Sun (R☉). At this radius, an object travelling at the speed of light would take over 6 hours to go around its surface, compared to just 14.5 seconds for the Sun. It is also one of the most luminous and massive red supergiants, with a luminosity around 282,000 times the solar luminosity (L☉) and a mass roughly 20 times that of the Sun (M☉). If placed at the center of the Solar System, the star's photosphere would engulf the orbit of Jupiter. The secondary component, being recently confirmed, is comparatively nowhere near as well-studied but it is at least understood to be a B-type star.
WOH G64 is surrounded by an optically thick dust envelope of roughly a light year in diameter, containing 3 to 9 times the Sun's mass of expelled material that was created by the strong stellar wind of the red supergiant primary.