Astronomy:HD 154857

From HandWiki
Short description: Star in the constellation of Ara
HD 154857
Observation data
Equinox J2000.0]] (ICRS)
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[1] mas
Distance209 ± 10 ly
(64 ± 3 pc)
Absolute magnitude (MV)3.07[2]
Details
Mass1.17 (± 0.05) M
Radius2.42 R
Luminosity4.61 L
Surface gravity (log g)5,579844548 g cgs
Temperature5445 K
Metallicity-0.23 (± 0.03) %
Age8.98 G years
Equatorial [ g ] 54,7 m/s2
Other designations
GC 23146, PPM 345752, TYC 8735-1682-1, CD-56° 6717, GSC 08735-01682, SAO 244491, uvby98 100154857, CPC 20 5475, CPD-56° 8059, HIP 84069
Database references
SIMBADdata

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]

The HD 154857 planetary system[3][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

  • List of extrasolar planets

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode2007A&A...474..653V. http://www.aanda.org/index.php?option=com_article&access=bibcode&Itemid=129&bibcode=2007A%2526A...474..653VFUL.  Vizier catalog entry
  2. 2.0 2.1 2.2 McCarthy, Chris et al. (2004). "Multiple Companions to HD 154857 and HD 160691". The Astrophysical Journal 617 (1): 575–579. doi:10.1086/425214. Bibcode2004ApJ...617..575M. 
  3. 3.0 3.1 O'Toole, Simon J. et al. (2007). "New Planets around Three G Dwarfs". The Astrophysical Journal 660 (2): 1636–1641. doi:10.1086/513563. Bibcode2007ApJ...660.1636O. 
  4. 4.0 4.1 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

Coordinates: Sky map 17h 11m 15.7219s, −56° 40′ 50.865″