HD 154857
Appearance
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Ara |
Right ascension | 17h 11m 15.72s[1] |
Declination | −56° 40′ 50.9″[1] |
Apparent magnitude (V) | 7.25 |
Characteristics | |
Spectral type | G5IV-V[2] |
B−V color index | 0.699 ± 0.001 |
Astrometry | |
Radial velocity (Rv) | 27.9 ± 0.2 km/s |
Proper motion (μ) | RA: 87.14 ± 0.56[1] mas/yr Dec.: -55.92 ± 0.46[1] mas/yr |
Parallax (π) | 15.57 ± 0.71 mas[1] |
Distance | 209 ± 10 ly (64 ± 3 pc) |
Absolute magnitude (MV) | 3.07[2] |
Details | |
Mass | 1.17 (± 0.05) M☉ |
Radius | 2.42 R☉ |
Luminosity | 4.61 L☉ |
Surface gravity (log g) | 5,579844548 g cgs |
Temperature | 5445 K |
Metallicity | -0.23 (± 0.03) % |
Age | 8.98 G years |
Equatorial [ g ] | 54,7 m/s2 |
Other designations | |
Database references | |
SIMBAD | data |
HD 154857 is a yellow main-sequence star approximately 209 light years[1] away in the constellation of Ara.
Planetary system
There is one confirmed and one unconfirmed planet discovered in 2004[2] and 2007[3] respectively. The confirmed planet HD 154857 b has mass >1.8 times that of Jupiter. It orbits the star 20% further than Earth-Sun distance, taking 409 days with 47% eccentricity. The previously reported additional object (HD 154857 c) was confirmed to have planetary nature in January 2014.[4]
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | >2.24±0.05 MJ | 1.291±0.008 | 408 ± 0.5 | 0.46 ± 0.02 | — | — |
c | ≥2.6 MJ | 5.36 | ~3470 | 0.06 | — | — |
See also
References
- ^ a b c d e f van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Vizier catalog entry
- ^ a b c McCarthy, Chris; et al. (2004). "Multiple Companions to HD 154857 and HD 160691". The Astrophysical Journal. 617 (1): 575–579. arXiv:astro-ph/0409335. Bibcode:2004ApJ...617..575M. doi:10.1086/425214.
- ^ a b O'Toole, Simon J.; et al. (2007). "New Planets around Three G Dwarfs". The Astrophysical Journal. 660 (2): 1636–1641. arXiv:astro-ph/0702213. Bibcode:2007ApJ...660.1636O. doi:10.1086/513563.
- ^ a b The Anglo-Australian Planet Search. XXIII. Two New Jupiter Analogs: Robert A. Wittenmyer, Jonathan Horner, C.G. Tinney, R.P. Butler, H.R.A. Jones, Mikko Tuomi, G.S. Salter, B.D. Carter, F. Elliott Koch, S.J. O'Toole, J. Bailey, D. Wright
External links
- "HD 154857". The Extrasolar Planets Encyclopaedia. Retrieved 2008-07-21.
- http://planetquest.jpl.nasa.gov