HD 147018

HD 147018 is a star in the southern constellation of Triangulum Australe.^[5] It has a yellow-orange hue with an apparent visual magnitude of 8.30,^[2] 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,^[1] but is drifting closer with a radial velocity of −27.5 km/s.^[2]

HD 147018

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Triangulum Australe
Right ascension	16h 23m 00.14702s[1]
Declination	−61° 41′ 19.5629″[1]
Apparent magnitude (V)	8.30[2]
Characteristics
Spectral type	G8/K0V[3]
Apparent magnitude (B)	9.063[2]
Apparent magnitude (J)	6.963±0.023[2]
Apparent magnitude (H)	6.640±0.044[2]
Apparent magnitude (K)	6.571±0.021[2]
B−V color index	0.763±0.002[2]
Astrometry
Radial velocity (Rv)	−27.5±0.3[2] km/s
Proper motion (μ)	RA: −177.498[1] mas/yr Dec.: −316.244[1] mas/yr
Parallax (π)	24.7079±0.0434 mas[1]
Distance	132.0 ± 0.2 ly (40.47 ± 0.07 pc)
Absolute magnitude (MV)	5.14[2]
Details[4]
Mass	0.927±0.031 M☉
Radius	0.94±0.02[1] R☉
Luminosity	0.712±0.002[1] L☉
Surface gravity (log g)	4.38±0.16 cgs
Temperature	5,441±55 K
Metallicity [Fe/H]	0.10±0.05 dex
Rotational velocity (v sin i)	1.56 km/s
Age	6.36±4.33 Gyr
Other designations
CD−61°5387, CPD−61°5655, HIP 80250, SAO 253526, LTT 6522, NLTT 42574[5]
Database references
SIMBAD	data
Exoplanet Archive	data

The stellar classification of HD 147018 is G8/K0V^[3] or G9V,^[4] 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 93%^[4] of the mass of the Sun and 94%^[1] of the Sun's radius. The metallicity, or abundance of heavier elements, is higher than in the Sun.^[4] The star is radiating 71%^[1] of the luminosity of the Sun from its photosphere at an effective temperature of 5,441 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.^[4]

The HD 147018 planetary system^[4]

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	—	—

See also

• List of extrasolar planets