54 Piscium

Planetary System : 54 Piscium
System Summary

54 Piscium is located about 36.2 light-years from Sol. It lies in the northwestern corner (0:39:21.8+21:15:1.7, ICRS 2000.0) of Constellation Pisces -- northeast of Algenib (Gamma Pegasi), southeast of Alpheratz (Alpha Andromedae), southwest of Delta Andromedae and Mirach (Beta Andromedae), west of the Triangulum Galaxy (M33) and Sheratan (Beta Arietis), and northwest of spiral galaxy M74 (NGC 628) and Delta and Epsilon Piscium. On January 16, 2003, astronomers announced the discovery of a Saturn-sized, planetary companion to this star (exoplanets.org -- more details below). (See an animation of the planetary and potentially habitable zone orbits of this system, with a table of basic orbital and physical characteristics.)

The Star

54 Piscium is an orange-red main-sequence dwarf star of spectral and luminosity type K0+ V. The star may have 79 percent of Sol's mass (exoplanets.org), 86 percent of its diameter (Johnson and Wright, 1983, page 645), and 46 to 49 percent of its luminosity. It appears to be around 1.1 times as enriched as Sol with elements heavier than hydrogen ("metallicity"), based on its abundance of iron (exoplanets.org). 54 Piscium is not chromospherically active (Fischer et al, 2003, in pdf), but it is a New Suspected Variable star designated NSV 245. Useful catalogue numbers and designations for the star include: 54 Psc, HR 166*, Gl 27, Hip 3093, HD 3651, BD+20 85, SAO 74175, LHS 1116, LTT 10224, and LFT 59.

The orbit of an Earth-like planet with surface water would be centered within 0.68 AU -- around the orbital distance Venus in the Solar System -- and take around 240 days (two-thirds of a year) to complete. However, the inner, eccentric orbit of a giant planetary companion "b" recently discovered around 54 Piscium would probably disturb the orbit of such an Earth-type planet. Astronomers would find it very difficult to detect an Earth-sized planet around this star using present methods.

System Components
(Mass in Multiples of Jupiter's Mass)

Location
Constellation:  Pisces
Right Ascension:  00 39 21.8061
Declination:  +21 15 01.701
Distance from Sol:  35.87 Light Years

Basic Data 

Spectral Type:  K0 V
Apparent Magnitude:  5.8
Mass:  0.79 Solar Masses
Radius:  0.9 Solar Radii
Effective Temperature:  5250 Kelvin
Metallicity:  0.05 [Fe/H]
1.12 times Solar
 
 Habitability
  
Inner Edge of Habitability Zone:  0.37 AU
Outer Edge of Habitability Zone:  1.16 AU
Estimated Stellar Lifespan  20282 million years
 

54 Piscium b

Blue Giant, Eccentric

Basic Data
Parent Star:  54 Piscium (K0 V)
Discovery Status:  Confirmed
Planet Type:  Blue Giant, Eccentric
 
  Physical Data
Mass ( M sin i ):  0.2 Jupiters
Periastron Distance:  0.1 AU
Mean Distance:  0.284 AU
Apastron Distance:  0.46 AU
Orbital Period:  62.23 Days
Eccentricity:  0.63
Argument of Perihelion (omega):  235.7°
 
 
  Inferred Properties
Average Angular Size of Star:  1.685°
Planet Appearance:
 Blue with sparse sulfur based clouds
Periastron Temp:  664 Kelvin
Mean Temp:  404 Kelvin
Apastron Temp:  316 Kelvin
 
 
 Discovery Facts
Year Discovered:  2003
Detection Method:  Doppler Spectroscopy
Discovered By:  FISCHER D., BUTLER P., MARCY G., VOGT S. & HENRY G.  

  Planetary Orbit Around 54 Piscium

Position In Pisces