Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Apus |
Right ascension | 14h 33m 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]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Apus |
Right ascension | 14h 33m 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]