6 Hydrae

This article is about 'a Hydrae'. Not to be confused with α (alpha) Hydrae.
6 Hydrae
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Hydra
Right ascension 08h 40m 01.47182s[1]
Declination −12° 28′ 31.3433″[1]
Apparent magnitude (V) 4.98[2]
Characteristics
Evolutionary stage giant
Spectral type K3 III[3]
B−V color index 1.415±0.001[2]
Astrometry
Radial velocity (Rv)−7.8±0.6[4] km/s
Proper motion (μ) RA: −81.619[1] mas/yr
Dec.: −1.646[1] mas/yr
Parallax (π)8.7394 ± 0.1769 mas[1]
Distance373 ± 8 ly
(114 ± 2 pc)
Absolute magnitude (MV)−0.40[2]
Details
Radius32.7+0.5
−2.6[1] R☉
Luminosity267±6[1] L☉
Surface gravity (log g)1.91[5] cgs
Temperature4,080+173
−30[1] K
Metallicity [Fe/H]−0.21[5] dex
Other designations
a Hya, 6 Hya, BD−11°2420, HD 73840, HIP 42509, HR 3431, SAO 154515[6]
Database references
SIMBADdata

6 Hydrae is a single[7] star in the equatorial constellation of Hydra,[6] located 373 light-years away from the Sun.[1] It has the Bayer designation a Hydrae; 6 Hydrae is the Flamsteed designation. This object is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.98.[2] It is moving closer to the Earth with a heliocentric radial velocity of −8 km/s.[4] Eggen (1995) listed it as a proper motion candidate for membership in the IC 2391 supercluster.[8]

This is an aging giant star with a stellar classification of K3 III,[3] which indicates it has exhausted the hydrogen at its core and evolved away from the main sequence. As a consequence, it has expanded to 33[1] times the radius of the Sun. The star is radiating 267[1] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,080 K.[1]

  1. ^ a b c d e f g h i j k l Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference houk1978 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference McWilliam1990 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Eggen1995 was invoked but never defined (see the help page).