Eta Cassiopeiae

light-years
Proper names: Eta Cassiopeiae, 24 Cassiopeiae
Catalog numbers:
     Gliese (Gl) 34, Henry Draper (HD) 4614, Bonner Durchmusterung (BD) +57°150, Hipparcos Input Catalog (HIC) 3821, Smithsonian Astrophysical Observatory (SAO) 21732, Aitken Double Star (ADS) 671, Hoffleit Bright Star (HR) 219, Struve (STF) 60
Age: 5800 million years
Source for age: Don C. Barry, "Chromospheric Age Dependence of…", APJ 334
Heavy element abundance: 65% of Sol
Standard error in heavy element abundance: 3%
Source for heavy element abundance: Strobel [Fe/H] Determinations
Arity: binary
Right Ascension and Declination: 0h49m5.798s, +57°48'58.44" (epoch 2000.0)
Distance from Sol: 19.42 light-years (5.953 parsecs)
Standard error in distance: 0.3677%
Source for distance: Hipparcos
Celestial (X,Y,Z) coordinates in ly: 10.11, 2.198, 16.43
Galactic (X,Y,Z) coordinates in ly: -10.54, 16.22, -1.619
Proper motion: 1.213 arcsec/yr (114.9° from north)
Radial Velocity: 8.2 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: -29.84, -11.08, -15.03

What do all these fields mean?

Data for A and B's orbit around one other:
Combined absolute visual magnitude: +4.55
Combined visual luminosity: 1.317 x Sol
Period: 480 years
Semimajor Axis: 71.40 A.U.s
Eccentricity: 0.497
Periastron distance: 35.91 A.U.s
Apastron distance: 106.9 A.U.s
Year in which periastron occurs: 1889.6
Source for orbit data: K.A. Strand
As seen from A:
     At periastron, B would appear as magnitude -15.16
     At apastron, B would appear as magnitude -12.79
As seen from B:
     At periastron, A would appear as magnitude -19.22
     At apastron, A would appear as magnitude -16.85


Component A:
Catalog numbers:
     Luyten Half-Second (LHS) 123
Spectral class: G3
Luminosity Class: V
Apparent visual magnitude: +3.45
Absolute visual magnitude: +4.58
Visual luminosity: 1.287 x Sol
Color indices: B-V= +0.57, U-B= +0.02, R-I= +0.22
Mass: 1.1 x Sol
Diameter: 1.011 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 1.134 A.U.s
Orbital period in CZ: 1.15181 years
Tidal index in CZ: 0.753766
Angular size of star in sky in CZ: 0.475092 degrees


Component B:
Catalog numbers:
     Luyten Half-Second (LHS) 122
Proper motion: 1.213 arcsec/yr (114.9° from north)
Radial Velocity: 10.5 km/sec
Source for proper motion and radial velocity: Gliese
Galactic (U,V,W) velocity components in km/s: -31.09, -9.154, -15.23
Spectral class: K7n
Luminosity Class: V
Apparent visual magnitude: +7.51
Absolute visual magnitude: +8.64
Visual luminosity: 0.0306 x Sol
Color indices: B-V= +1.39, U-B= +1.03, R-I= +0.59
Mass: 0.52 x Sol
Diameter: 0.646 x Sol
Source for diameter: Apparent Diameters and Absolute Radii of Stars (Fracassini+ 1988)
Comfort Zone (visual): 0.175 A.U.s
Orbital period in CZ: 37.0345 days
Tidal index in CZ: 97.2673
Angular size of star in sky in CZ: 1.970070 degrees

light-years
but not more than light-years away
Data for this star system were most recently updated on 4-April-2001.