Ross 548
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cetus |
| Right ascension | 01h 36m 13.61558s |
| Declination | −11° 20′ 32.6318″ |
| Apparent magnitude (V) | 14.16±0.01 |
| Characteristics | |
| Evolutionary stage | White dwarf |
| Spectral type | DA4.0 |
| U−B color index | −0.5 |
| B−V color index | 0.2 |
| Variable type | ZZ Cet (DAV) |
| Astrometry | |
| Proper motion (μ) | RA: +460.845 mas/yr Dec.: −116.448 mas/yr |
| Parallax (π) | 30.5249±0.0546 mas |
| Distance | 106.8 ± 0.2 ly (32.76 ± 0.06 pc) |
| Absolute magnitude (MV) | 11.78±0.06 |
| Details | |
| Mass | 0.65±0.02 M☉ |
| Radius | 0.0118±0.0002 R☉ |
| Luminosity | 0.0029±0.0002 L☉ |
| Surface gravity (log g) | 8.108±0.025 cgs |
| Temperature | 12,281±125 K |
| Rotation | 37.84±1.99 h |
| Other designations | |
| ZZ Cet, EGGR 10, G 271-106, G 272-52, LTT 873, NLTT 5358, WD 0133-116 | |
| Database references | |
| SIMBAD | data |
Ross 548 is a white dwarf in the equatorial constellation of Cetus. With a mean apparent visual magnitude of 14.2 it is much too faint to be visible to the naked eye. Based on parallax measurements, it is located at a distance of 107 light years from the Sun. It was found to be variable in 1970 and in 1972 it was given the variable star designation ZZ Ceti. This is a pulsating white dwarf of the DAV type that is the prototype of the ZZ Ceti variable class., pp. 891, 895.
This DA-class white dwarf is the surviving core of a red giant star that ceased nuclear fusion while shedding its outer envelope. It has a (presumably) homogeneous core of carbon and oxygen, a relatively thin outer envelope of hydrogen, and a helium mantle. The object has 65% of the mass of the Sun, with 1.2% of the Sun's radius. It is radiating 0.3% of the luminosity of the Sun at an effective temperature of 12,281 K. Ross 548 is spinning with a period of ~38 hours. The dominant pulsation mode of this object has a period of 213.1326 seconds. It has up to 11 known pulsation modes in total.