HD 154345
Coordinates: 
17h 02m 36.40s, +47° 04′ 54.77″
17h 02m 36.40s, +47° 04′ 54.77″| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Hercules |
| Right ascension | 17h 02m 36.40381s[1] |
| Declination | +47° 04′ 54.7642″[1] |
| Apparent magnitude (V) | +6.76[2] |
| Characteristics | |
| Spectral type | G8V[3] |
| U−B color index | 0.27 |
| B−V color index | 0.728±0.005[2] |
| Absolute magnitude (MV) | +5.41[2] |
| Details Gyr | |
GCRV 9834[7] | |
| Database references | |
| SIMBAD | data |
HD 154345 is a
light years based on parallax, but it is drifting closer with a radial velocity of −47 km/s.[1] At least one exoplanet is orbiting this star.[9]
The
rotation period of 28 days.[6] 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.[9] It has been called a "Jupiter twin".[12] While the existence of HD 154345 b has been unclear due to the correlation of its orbital period with the star's activity cycle,[10] a study in 2021 further confirmed its planetary nature.[13]
The complete observation of its nine-year orbit rules out any interior planets of minimum mass (m sini) greater than 0.3 Jupiter.[12] The star rotates at an inclination of 50+40
−26 degrees relative to Earth.[6] It is probable that the planet shares that inclination.[14][15] 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.[16]
The system's habitable zone stretches from 0.64 AU out to 1.26 AU, and is narrower than the Sun's. It forms a stable region where an Earth-mass exoplanet could orbit.[17]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (years) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 1.19+0.14 −0.11 MJ |
4.2+0.14 −0.15 |
9.15±0.11 | 0.157+0.03 −0.029 |
69+13 −12 or 111+12 −13° |
— |
References
- ^ S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ S2CID 119257644.
- ^ doi:10.1086/110413.
- ^ S2CID 53971692. A5.
- S2CID 62799777. A55.
- ^ S2CID 6708869.
- ^ "HD 154345". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-01-19.
- ^ "The astronomical magnitude scale". International Comet Quarterly. Retrieved 2021-01-19.
- ^ S2CID 35682784.
- ^ Bibcode:2015tyge.conf....8W.
- Bibcode:2015IAUGA..2258453W. 2258453.
- ^ S2CID 16808434.
- S2CID 235186973.
- ^ "hd_154345_b". Extrasolar Planets Encyclopaedia. 1995. Retrieved November 12, 2012.
- S2CID 38743202.
- ^ S2CID 257663647.
- . A98.
External links
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