HD 154345
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Hercules[1] |
| Right ascension | Template:RA[2] |
| Declination | Template:DEC[2] |
| Apparent magnitude (V) | +6.76[1] |
| Characteristics | |
| Spectral type | G8V[3] |
| U−B Template:Engvar | 0.27 |
| B−V Template:Engvar | Script error: No such module "val".[1] |
| Astrometry | |
| Radial velocity (Rv) | Script error: No such module "val".[2] km/s |
| Proper motion (μ) | RA: 123.274 mas/yr[2] Dec.: 853.639 mas/yr[2] |
| Parallax (π) | 54.7359±0.0176 mas[2] |
| Distance | Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc) |
| Absolute magnitude (MV) | +5.41[1] |
| Details[4] | |
| Mass | Script error: No such module "val".[5] Template:Solar mass |
| Radius | Script error: No such module "val". Template:Solar radius |
| Luminosity | Script error: No such module "val". Template:Solar luminosity |
| Surface gravity (log g) | Script error: No such module "val". cgs |
| Temperature | Script error: No such module "val". K |
| Metallicity [Fe/H] | Script error: No such module "val".[6] dex |
| Rotation | Script error: No such module "val".[7] |
| Age | Script error: No such module "val". Gyr |
| Metallicity [Fe/H] | {{{metal_fe2}}} dex |
| Other designations | |
| Template:Odlist[8] | |
| Database references | |
| SIMBAD | data |
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HD 154345 is a star in the northern constellation of Hercules. With an apparent visual magnitude of +6.76[1] it is a challenge to view with the naked eye, but using binoculars it is an easy target.[9] The distance to this star is 59.6 light years based on parallax, but it is drifting closer with a radial velocity of −47 km/s.[2] At least one exoplanet is orbiting this star.[10]
The stellar classification of HD 154345 is G8V,[3] matching an ordinary G-type main-sequence star that is generating energy by core hydrogen fusion. The magnetic activity cycle of this star is curiously correlated with the radial velocity variations induced by its putative planetary companion.[11][12] It is around four[4] billion years old and is spinning with a rotation period of 28 days.[7] The star is smaller and less massive than the Sun. It is radiating 62% of the luminosity of the Sun from its photosphere at an effective temperature of 5,557 K.[4]
Planetary system
In 2006, a long-period, wide-orbiting planet was observed by radial velocity, and published in May 2007, gaining the designation HD 154345 b.[10] It has been called a "Jupiter twin".[13] While the existence of HD 154345 b has been unclear due to the correlation of its orbital period with the star's activity cycle,[11] a study in 2021 further confirmed its planetary nature.[14]
The complete observation of its nine-year orbit rules out any interior planets of minimum mass (m sini) greater than 0.3 Jupiter.[13] The star rotates at an inclination of 50Script error: No such module "Su". degrees relative to Earth.[7] It is probable that the planet shares that inclination.[15][16] In 2023, the inclination and true mass of HD 154345 b were determined via astrometry, consistent within the margin of error with the stellar rotational inclination.[17] More precise measurements found a nearly edge-on inclination.[5]
The system's habitable zone stretches from Script error: No such module "val". out to Script error: No such module "val"., and is narrower than the Sun's. It forms a stable region where an Earth-mass exoplanet could orbit.[18]
Template:OrbitboxPlanet begin Template:OrbitboxPlanet
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References
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