58 Hydrae

58 Hydrae
Observation data
Epoch J2000      Equinox J2000
Constellation Hydra
Right ascension 14h 50m 17.30146s[1]
Declination −27° 57′ 37.3385″[1]
Apparent magnitude (V) 4.42[2]
Characteristics
Evolutionary stage giant
Spectral type K2.5 IIIb Fe-1:[3]
B−V color index 1.366±0.050[2]
Astrometry
Radial velocity (Rv)−8.7±1.5[2] km/s
Proper motion (μ) RA: −232.696[1] mas/yr
Dec.: −60.118[1] mas/yr
Parallax (π)11.4440 ± 0.5105 mas[1]
Distance290 ± 10 ly
(87 ± 4 pc)
Absolute magnitude (MV)−0.60[2]
Details[4]
Mass0.88 M☉
Radius33.40+0.41
−1.13[1] R☉
Luminosity310.19 L☉
Surface gravity (log g)1.35 cgs
Temperature4,210 K
Metallicity [Fe/H]−0.43±0.04[2] dex
Age8.1 Gyr
Other designations
E Hya, 58 Hya, CD−27°10073, HD 130694, HIP 72571, HR 5526, SAO 182911, LTT 5887[5]
Database references
SIMBADdata

58 Hydrae is a single[6] star in the equatorial constellation of Hydra, located around 290 light years away from the Sun based on parallax.[1] It has the Bayer designation E Hydrae; 58 Hydrae is the Flamsteed designation − a later designation of 6 Librae.[7] It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.42.[2] This object is moving closer to the Earth with a heliocentric radial velocity of −9 km/s.[2]

This is an aging giant star with a stellar classification of K2.5 IIIb Fe-1:,[3] most likely (98% chance) on the red giant branch.[4] The suffix notation indicates an underabundance of iron in the spectrum, and some uncertainty about the classification. It is around 8.1 billion years old with 0.88 times the mass of the Sun.[4] As a consequence of exhausting the hydrogen at its core, the star has expanded to 33.4[1] times the Sun's radius. It is radiating 310 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,210 K.[4]

  1. ^ a b c d e f g h Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d e f g Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Keenan1989 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference Stock2018 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Wagman1987 was invoked but never defined (see the help page).