Rho(1) Cancri

Proper names: Rho(1) Cancri, 55 Cancri, Rho Cancri
Catalog numbers:
Gliese (Gl) 324, Henry Draper (HD) 75732, Bonner Durchmusterung (BD) +28°1660, Hipparcos Input Catalog (HIC) 43587, Smithsonian Astrophysical Observatory (SAO) 80478, Hoffleit Bright Star (HR) 3522
Heavy element abundance: 143% of Sol
Standard error in heavy element abundance: 19%
Source for heavy element abundance: Strobel [Fe/H] Determinations
Arity: binary
Points of interest:
The A star has at least one planet. The planet's mass is at least 0.8 times that of Jupiter, with a diameter anywhere from 0.35 to 1.35 times that of Jupiter -- all perfectly good values for a gas-giant planet. Its orbit is nearly circular, too, indicating that this probably isn't a brown dwarf. However, like the planet orbiting 51 Pegasi, 55 Cancri A's planet orbits very close to the star, at a distance of only 0.11 A.U.s (thus completing one orbit every 14.76 days).

Right Ascension and Declination: 8h52m35.832s, +28°19'51.16" (epoch 2000.0)
Distance from Sol: 40.9 light-years (12.5 parsecs)
Standard error in distance: 1.0417%
Source for distance: Hipparcos
Celestial (X,Y,Z) coordinates in ly: -24.6, 26.2, 19.4
Galactic (X,Y,Z) coordinates in ly: -30.6, -9.50, 25.3
Proper motion: 0.528 arcsec/yr (243.9° from north)
Radial Velocity: 27.2 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: -36.6, -18.3, -7.21

What do all these fields mean?

Data for A and B's orbit around one other:
Combined absolute visual magnitude: +5.46
Combined visual luminosity: 0.57 x Sol
Observed Separation: 1065 A.U.s
As seen from A:
B would appear as magnitude -3.78
As seen from B:
A would appear as magnitude -10.98

Component A:
Catalog numbers:
     Luyten Half-Second (LHS) 2062
Spectral class: G8
Luminosity Class: V
Apparent visual magnitude: +5.95
Absolute visual magnitude: +5.46
Visual luminosity: 0.57 x Sol
Color indices: B-V= +0.86, U-B= +0.62, R-I= +0.26
Mass: 0.85 x Sol
Diameter: 0.91 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 0.76 A.U.s
Orbital period in CZ: 259.937 days
Tidal index in CZ: 1.97444
Angular size of star in sky in CZ: 0.642492 degrees
Detected companions: 1
Companion b:
     Mass: 0.8 x Jupiter, minimum
     Period: 14.76 days
     Semimajor Axis: 0.11 A.U.s

Component B:
Catalog numbers:
Giclas (G) 47-9, Luyten Half-Second (LHS) 2063
Right Ascension and Declination: 8h49m42s, +28°30'30" (epoch 1950.0)
Celestial (X,Y,Z) coordinates in ly: -24.2, 26.5, 19.5
Galactic (X,Y,Z) coordinates in ly: -30.9, -9.36, 25.0
Proper motion: 0.538 arcsec/yr (243.7° from north)
Radial Velocity: 25.2 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: -35.4, -17.8, -9.29
Spectral class: M3.5
Luminosity Class: V
Apparent visual magnitude: +13.14
Absolute visual magnitude: +12.65
Visual luminosity: 0.00076 x Sol
Color indices: B-V= +1.64, U-B= +1.20, R-I= +1.30
Mass: 0.13 x Sol
Diameter: 0.3 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 0.028 A.U.s
Orbital period in CZ: 4.62914 days
Tidal index in CZ: 6225.59
Angular size of star in sky in CZ: 5.807884 degrees

Data for this star system were most recently updated on 4-April-2001.