| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cetus[1] |
| Right ascension | 00h 77m 01.3977s[2] |
| Declination | +00° 47′ 22.401″[2] |
| Apparent magnitude (V) | 8.05 |
| Characteristics | |
| Spectral type | K3IV[3] |
| Astrometry | |
| Proper motion (μ) | RA: −5.398±0.105[2]mas/yr Dec.: −49.564±0.063[2]mas/yr |
| Parallax (π) | 8.2083±0.0476 mas[2] |
| Distance | 397 ± 2 ly (121.8 ± 0.7 pc) |
| Absolute magnitude (MV) | +2.78[1] |
| Details | |
| Mass | 1.40 ± 0.14[4] M☉ |
| Radius | 3.97 ± 0.43[4] R☉ |
| Luminosity | 9[4] L☉ |
| Temperature | 4,921[2] K |
| Metallicity[Fe/H] | +0.14[4] dex |
| Age | 3.30 ± 1.11[4] Gyr |
| Other designations | |
| BD+00°142,HIP 4297,SAO 109532,2MASS 2MASS J00550140+0047223, Gaia DR2 2537319343919089024 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HD 5319 is an 8thmagnitudestar approximately 319light years away in theconstellationCetus. It is asubgiant star ofspectral type K3, having run out ofhydrogen in its core. When it wasmain-sequence, the spectral type was early F or late A.
Theabsolute magnitude (apparent magnitude at 10parsecs) is 3.05, which would translate to easy naked eye visibility, but its distance is ten times greater, so itsapparent magnitude is 8.05 (100 times fainter than its absolute magnitude), it is not visible to thenaked eye andbinoculars are needed.
On January 11, 2007, theCalifornia and Carnegie Planet Search team found anextrasolar planet with a minimum mass 1.76 times that ofJupiter orbiting the star. It was published in the December 1, 2007 edition of theAstrophysical Journal.[5] A second planet was discovered in November 2014. Orbital simulations of the dynamical stability of the planetary system indicate that it is likely in a 4:3mean motion resonance.[3] Previous computer simulations have shown an inability to reproduce this resonance in gas giant systems using a variety of formation and migration mechanisms.[6] Additional analysis on the stability of the system show that the planets orbits may have to beinclined to one another to maintain stability,[7] although simplest solution as in 2019 still indicate the planetary system of HD 5319 is unstable.[8]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥1.56±0.29 MJ | 1.57±0.13 | 638.6±1.2 | 0.015±0.016 | — | — |
| c | ≥1.02±0.22 MJ | 1.94±0.16 | 877.0±4.9 | 0.109±0.067 | — | — |
