Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Hydra |
Right ascension | 08h 41m 43.33591s [1] |
Declination | −15° 56′ 36.1727″ [1] |
Apparent magnitude (V) | 4.866 [2] |
Characteristics | |
Spectral type | K0 III CNII [3] |
U−B color index | +0.92 [4] |
B−V color index | +1.07 [4] |
Astrometry | |
Radial velocity (Rv) | −1.98±0.12 [1] km/s |
Proper motion (μ) |
RA: 3.676
[1]
mas/
yr Dec.: -97.743 [1] mas/ yr |
Parallax (π) | 15.9089 ± 0.1297 mas [1] |
Distance | 205 ± 2
ly (62.9 ± 0.5 pc) |
Absolute magnitude (MV) | +0.81 [5] |
Details [6] | |
Mass | 1.72±0.46 [7] M☉ |
Radius | 11.10+0.15 −0.69 [1] R☉ |
Luminosity | 54.445+0.536 −0.457 [1] L☉ |
Surface gravity (log g) | 2.8 cgs |
Temperature | 4,688±5 K |
Metallicity [Fe/H] | −0.01 dex |
Rotational velocity (v sin i) | 1.7 km/s |
Other designations | |
Database references | |
SIMBAD | data |
9 Hydrae is a single [9] star in the equatorial constellation of Hydra, [8] located 205 light years away from the Sun. [1] It is visible to the naked eye as a faint, yellow-orange hued star with an apparent visual magnitude of 4.87. [2] This body is moving closer to the Sun with a heliocentric radial velocity of −2 km/s. [1]
This is an aging giant star with a stellar classification of K0 III CNII, [3] where the suffix notation indicates an overabundance of cyanogen in the spectrum. It is a red clump giant, [10] which indicates it is on the horizontal branch and is generating energy through helium fusion at its core. The star has 1.7 [7] times the mass of the Sun but, as a consequence of evolving away from the main sequence, its envelope has swollen to 11 [1] times the Sun's radius. It is radiating 54 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,688 K. [6]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Hydra |
Right ascension | 08h 41m 43.33591s [1] |
Declination | −15° 56′ 36.1727″ [1] |
Apparent magnitude (V) | 4.866 [2] |
Characteristics | |
Spectral type | K0 III CNII [3] |
U−B color index | +0.92 [4] |
B−V color index | +1.07 [4] |
Astrometry | |
Radial velocity (Rv) | −1.98±0.12 [1] km/s |
Proper motion (μ) |
RA: 3.676
[1]
mas/
yr Dec.: -97.743 [1] mas/ yr |
Parallax (π) | 15.9089 ± 0.1297 mas [1] |
Distance | 205 ± 2
ly (62.9 ± 0.5 pc) |
Absolute magnitude (MV) | +0.81 [5] |
Details [6] | |
Mass | 1.72±0.46 [7] M☉ |
Radius | 11.10+0.15 −0.69 [1] R☉ |
Luminosity | 54.445+0.536 −0.457 [1] L☉ |
Surface gravity (log g) | 2.8 cgs |
Temperature | 4,688±5 K |
Metallicity [Fe/H] | −0.01 dex |
Rotational velocity (v sin i) | 1.7 km/s |
Other designations | |
Database references | |
SIMBAD | data |
9 Hydrae is a single [9] star in the equatorial constellation of Hydra, [8] located 205 light years away from the Sun. [1] It is visible to the naked eye as a faint, yellow-orange hued star with an apparent visual magnitude of 4.87. [2] This body is moving closer to the Sun with a heliocentric radial velocity of −2 km/s. [1]
This is an aging giant star with a stellar classification of K0 III CNII, [3] where the suffix notation indicates an overabundance of cyanogen in the spectrum. It is a red clump giant, [10] which indicates it is on the horizontal branch and is generating energy through helium fusion at its core. The star has 1.7 [7] times the mass of the Sun but, as a consequence of evolving away from the main sequence, its envelope has swollen to 11 [1] times the Sun's radius. It is radiating 54 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,688 K. [6]