HD 147018
Star in the southern constellation of Triangulum Australe
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HD 147018 is a star in the southern constellation of Triangulum Australe.[7] It has a yellow-orange hue with an apparent visual magnitude of 8.30,[1] which is too faint to be seen with the naked eye but can be viewed with a small telescope. The star is located at a distance of 132 light years from the Sun based on parallax,[2] but is drifting closer with a radial velocity of −27.5 km/s.[1]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Triangulum Australe[1] |
| Right ascension | 16h 23m 00.14788s[2] |
| Declination | −61° 41′ 19.5599″[2] |
| Apparent magnitude (V) | 8.30[1] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | G8/K0V[3] |
| Apparent magnitude (B) | 9.063[1] |
| Apparent magnitude (J) | 6.963±0.023[1] |
| Apparent magnitude (H) | 6.640±0.044[1] |
| Apparent magnitude (K) | 6.571±0.021[1] |
| B−V color index | 0.763±0.002[1] |
| Astrometry | |
| Radial velocity (Rv) | −27.5±0.3[1] km/s |
| Proper motion (μ) | RA: −177.896[2] mas/yr Dec.: −316.435[2] mas/yr |
| Parallax (π) | 24.7763±0.0217 mas[2] |
| Distance | 131.6 ± 0.1 ly (40.36 ± 0.04 pc) |
| Absolute magnitude (MV) | 5.14[1] |
| Details | |
| Mass | 0.96±0.12[4] M☉ |
| Radius | 0.93±0.04[4] R☉ |
| Luminosity | 0.71±0.02[4] L☉ |
| Surface gravity (log g) | 4.48±0.08[4] cgs |
| Temperature | 5,489±110 K |
| Metallicity [Fe/H] | 0.10±0.05[5] dex |
| Rotation | 31.1 days[6] |
| Rotational velocity (v sin i) | 1.56[5] km/s |
| Age | 6.36±4.33[5] Gyr |
| Other designations | |
| CD−61°5387, CPD−61°5655, HIP 80250, SAO 253526, LTT 6522, NLTT 42574[7] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
The stellar classification of HD 147018 is G8/K0V[3] or G9V,[5] matching a late G-type main-sequence star that is generating energy through core hydrogen fusion. It is roughly six billion years old and is spinning with a projected rotational velocity of 1.56 km/s. The star has 96% of the mass of the Sun and 93% of the Sun's radius.[4] The metallicity, or abundance of heavier elements, is higher than in the Sun.[5] The star is radiating 71% of the luminosity of the Sun from its photosphere at an effective temperature of 5,489 K.[4]
In August 2009, two extrasolar planets, HD 147018 b and HD 147018 c, were reported to be orbiting this star. The planets were found using the radial velocity method, using the CORALIE spectrograph at La Silla Observatory, Chile.[5]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥2.12±0.07 MJ | 0.2388±0.0039 | 44.236±0.008 | 0.4686±0.0081 | — | — |
| c | ≥6.56±0.32 MJ | 1.922±0.039 | 1,008±18 | 0.133±0.011 | — | — |