HD 154857

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HD 154857
Observation data
Epoch J2000.0
Constellation
(pronunciation)
Ara
Right ascension 17h 11m 15.7219s
Declination –56° 40′ 50.865″
Apparent magnitude (V) 7.25
Distance 223.55 ly
(68.54 pc)
Spectral type G5V
Other designations
HIP 84069, SAO 244491

HD 154857 is a star in the constellation Ara. Like our Sun, it is a yellow dwarf.

Contents

[edit] Planets

There is one confirmed and one unconfirmed planet discovered in 2004 and 2007 respectively.

[edit] HD 154857 b

HD 154857 b
Extrasolar planet List of extrasolar planets
Orbital elements
Semimajor axis (a) 1.2±0.2 AU
Eccentricity (e) 0.47±0.02
Orbital period (P) 409±1 d
Angular distance (θ) 17.518 mas
Longitude of
periastron
(ω) 59±4°
Time of periastron (T0) 2450346±5 JD
Semi-amplitude (K) 50.4±1 m/s
Physical characteristics
Mass (m) > 1.8±0.4 MJ
Discovery information
Discovery date 2004
Discoverer(s) McCarthy et al.
Detection method Radial velocity
Discovery status Published

HD 154857 b is an extrasolar planet of gas giant mass that orbits the star in an eccentric orbit. This planet was detected by using Anglo-Australian Telescope (AAT) UCLE spectrometer.

[edit] HD 154857 c

HD 154857 c
Extrasolar planet List of extrasolar planets
Orbital elements
Eccentricity (e) 0.25
Orbital period (P) 1900 d
Discovery information
Discovery date 2007
Discoverer(s) O' Toole
Detection method Radial velocity
Discovery status Unconfirmed

HD 154857 c is a possible planet discovered in 2007, together with HD 23127 b and HD 159868 b. More measurements are required to confirm its existence.

[edit] References

[edit] External links