| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Apus |
| Right ascension | 14h33m 07.636s[1] |
| Declination | −81° 20′ 14.13″[1] |
| Apparent magnitude (V) | 13.75[2] |
| Characteristics | |
| Evolutionary stage | Compact star |
| Spectral type | DA4.1[2] |
| U−B color index | −0.530 |
| B−V color index | 0.25 |
| Variable type | ZZ Cet[2][3] |
| Astrometry | |
| Radial velocity (Rv) | 58.0[4] km/s |
| Proper motion (μ) | RA: −154.665 mas/yr[1] Dec.: −389.971 mas/yr[1] |
| Parallax (π) | 47.7874 ± 0.0295 mas |
| Distance | 68.25 ± 0.04 ly (20.93 ± 0.01 pc) |
| Absolute magnitude (MV) | 11.86[2] |
| Details | |
| Mass | 0.705±0.023[5] M☉ |
| Radius | 0.011±0.001[5] R☉ |
| Luminosity | 0.00347[6] L☉ |
| Surface gravity (log g) | 8.17±0.04[2] cgs |
| Temperature | 12,330±182[2] K |
| Rotation | 13 h[7] |
| Other designations | |
| Database references | |
| SIMBAD | data |
MY Apodis, also known as L 19-2, GJ 2108, or WD 1425-811, is a single[6] white dwarf star located in the far southern constellation Apus. It is a low-amplitude variable star[9] with an average apparent visual magnitude of 13.75[2] and thus is much too faint to be visible to the naked eye. Based on parallax measurements, this star is located at a distance of 68.3 light-years from the Sun. It is drifting further away with a radial velocity of 58.0[4]
This compact stellar remnant has a class of DA4.1,[2] which indicates a hydrogen-rich outer atmosphere. It is a pulsating white dwarf (ZZ Ceti star) that varies photometrically with an amplitude of 0.05 in visual magnitude.[3] The low-amplitude variability of this ZZ Ceti analog was discovered by James E. Hesser and associates in 1974, who found it showed periods of 192.75±0.1 and 113.77±0.1 seconds.[9] By 2015, ten different pulsation modes had been identified, and it remained stable over four decades of observation.[10]
MY Apodis has 70.5%[5] of the mass of the Sun compressed down into 1.1%[5] of the Sun's radius. It is spinning rapidly with a rotation period of 13 hours.[7] The star is radiating just 0.35%[6] of the luminosity of the Sun at an effective temperature of 12,330 K.[2] Astroseismological models suggest the star has a thin outer hydrogen shell with a mass of 1.0×10−4 M☉, an intermediate helium layer of 1.5 to 2.0×10−2 M☉, and a core of 20% carbon and 80% oxygen that extends out to 60% of the stellar radius.[7]
