HD 121504 is a star with an orbiting exoplanet in the southern constellation of Centaurus. It is located at a distance of 136 light years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of 19.6 km/s.[5] With an apparent visual magnitude of 7.54,[1] this star is too faint to be visible to the naked eye. It shows a high proper motion, traversing the celestial sphere at an angular rate of 0.270 arcsec yr−1.[8]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Centaurus[1] |
Right ascension | 13h 57m 17.239s[2] |
Declination | −56° 02′ 24.16″[2] |
Apparent magnitude (V) | 7.54[1] |
Characteristics | |
Spectral type | G2V[3] |
B−V color index | 0.593±0.002[4][1] |
Astrometry | |
Radial velocity (Rv) | 19.603±0.0004[5] km/s |
Proper motion (μ) | RA: −249.354 mas/yr[2] Dec.: −84.570 mas/yr[2] |
Parallax (π) | 24.0593 ± 0.0269 mas[2] |
Distance | 135.6 ± 0.2 ly (41.56 ± 0.05 pc) |
Absolute magnitude (MV) | 4.27[1] |
Details | |
Mass | 1.16±0.02[6] M☉ |
Radius | 1.15±0.03[6] R☉ |
Luminosity | 1.62±0.04[6] L☉ |
Surface gravity (log g) | 4.38±0.03[6] cgs |
Temperature | 6,089±47[6] K |
Metallicity [Fe/H] | 0.16[4] dex |
Rotation | 8.6 days[4] |
Rotational velocity (v sin i) | 2.6[4] km/s |
Age | 1.9±1.0[6] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Exoplanet Archive | data |
The spectrum of this star presents as an ordinary G-type main-sequence star, a yellow dwarf similar in appearance to the Sun, having a stellar classification of G2V.[3] It is roughly two billion years old and is spinning with a rotation period of 8.6 days. The star has 16% more mass than the Sun and a 15% greater radius.[6] The metallicity (the abundance of elements more massive than helium) is higher than solar.[4] The star is radiating 162% of the luminosity of the Sun from its photosphere at an effective temperature of 6,089 K.[6]
A nearby visual companion, designated as SAO 241323 has been proposed as a component of the system. However, the pair form an optical binary with an angular separation of 34.2″,[4] and in reality this is a white giant star located thousands of light years away.[citation needed]
In 2000 the Geneva Extrasolar Planet Search Team announced the discovery of an extrasolar planet orbiting the star.[9]
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | >1.22 MJ | 0.33 | 63.33 ± 0.03 | 0.03 ± 0.01 | — | — |