Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Hydrus |
Right ascension | 02h 45m 32.63435s [1] |
Declination | −67° 36′ 59.8268″ [1] |
Apparent magnitude (V) | 4.83 [2] |
Characteristics | |
Spectral type | A2IV [2] |
U−B color index | +0.09 [3] |
B−V color index | +0.06 [3] |
Astrometry | |
Radial velocity (Rv) | +3.60 [4] km/s |
Proper motion (μ) |
RA: +66.41
[1]
mas/
yr Dec.: +43.38 [1] mas/ yr |
Parallax (π) | 11.47 ± 0.17 mas [1] |
Distance | 284 ± 4
ly (87 ± 1 pc) |
Absolute magnitude (MV) | 0.13 [2] |
Details | |
Mass | 2.44 [5] M☉ |
Radius | 3.9 [5] R☉ |
Luminosity | 79.55 [2] L☉ |
Surface gravity (log g) | 3.72 [6] cgs |
Temperature | 9,144 [6] K |
Rotational velocity (v sin i) | 116 [6] km/s |
Other designations | |
Database references | |
SIMBAD | data |
Zeta Hydri, Latinized from ζ Hydri, is a single, [7] white-hued star in the southern constellation of Hydrus. It is faintly visible to the naked eye with an apparent magnitude of 4.83. [2] This distance to this star can be estimated from its annual parallax shift of 11.47 mas, [1] showing it to be about 284 light years away. It is moving further away from the Sun with a radial velocity of +3.6 km/s. [4]
The spectrum of this star matches a stellar classification of A2 IV, [2] suggesting it is a subgiant star that is in the process of evolving away from the main sequence as the supply of hydrogen at its core becomes exhausted. It has a high rate of spin, showing a projected rotational velocity of 116 km/s. [6] This is giving the star a slight oblate shape with an equatorial bulge that is 5% larger than the polar radius. [8] It has 2.4 times the mass of the Sun and nearly four times the Sun's radius. [5] Zeta Hydri is radiating 80 [2] times the Sun's luminosity into space from its photosphere at an effective temperature of 9,144 K. [6]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Hydrus |
Right ascension | 02h 45m 32.63435s [1] |
Declination | −67° 36′ 59.8268″ [1] |
Apparent magnitude (V) | 4.83 [2] |
Characteristics | |
Spectral type | A2IV [2] |
U−B color index | +0.09 [3] |
B−V color index | +0.06 [3] |
Astrometry | |
Radial velocity (Rv) | +3.60 [4] km/s |
Proper motion (μ) |
RA: +66.41
[1]
mas/
yr Dec.: +43.38 [1] mas/ yr |
Parallax (π) | 11.47 ± 0.17 mas [1] |
Distance | 284 ± 4
ly (87 ± 1 pc) |
Absolute magnitude (MV) | 0.13 [2] |
Details | |
Mass | 2.44 [5] M☉ |
Radius | 3.9 [5] R☉ |
Luminosity | 79.55 [2] L☉ |
Surface gravity (log g) | 3.72 [6] cgs |
Temperature | 9,144 [6] K |
Rotational velocity (v sin i) | 116 [6] km/s |
Other designations | |
Database references | |
SIMBAD | data |
Zeta Hydri, Latinized from ζ Hydri, is a single, [7] white-hued star in the southern constellation of Hydrus. It is faintly visible to the naked eye with an apparent magnitude of 4.83. [2] This distance to this star can be estimated from its annual parallax shift of 11.47 mas, [1] showing it to be about 284 light years away. It is moving further away from the Sun with a radial velocity of +3.6 km/s. [4]
The spectrum of this star matches a stellar classification of A2 IV, [2] suggesting it is a subgiant star that is in the process of evolving away from the main sequence as the supply of hydrogen at its core becomes exhausted. It has a high rate of spin, showing a projected rotational velocity of 116 km/s. [6] This is giving the star a slight oblate shape with an equatorial bulge that is 5% larger than the polar radius. [8] It has 2.4 times the mass of the Sun and nearly four times the Sun's radius. [5] Zeta Hydri is radiating 80 [2] times the Sun's luminosity into space from its photosphere at an effective temperature of 9,144 K. [6]