55 Cancri (IHD 75732, LHS 2062, ρ1 Cancri, HR 3522, LDS
2619)
This star is quite similar to the Sun:
- Spectral Type G8V (Sun is G2V)
- Effective temperature 5279K (Sun is
5800K)
- Radius 1.15 x radius of the Sun.
- Mass 0.95 - 1.03 solar masses.
- Age 5.5 Gy. (Sun 4.6 Gy).
Apart from having several planets, 55 Cnc
has a companion star "55Cnc B" (not to be confused with "55 Cnc
b" which is a planet). The companion is a Red Dwarf of spectral type
M4 or M5. It is located about 1.44 arcminutes from the main star. The
pair are at a distance of 12.5pc (40.9ly) and their separation must be
at least 1000AU. Their orbital period round their common centre
of gravity must be of the order 20,000-30,000 years.
Five planets have been officially
announced as discoveries using the radial velocity method. They
have periods and masses of :
| |
Period (days) |
Mass (Jupiters) |
| b |
14.65 |
0.824 |
| c |
44.34 |
0.169 |
| d |
5218 |
3.835 |
| e |
2.817 |
0.034 |
| f |
260 |
0.144 |
This integration shows the 55 Cancri
system assuming a central mass of 0.95 solar masses and uses
orbital parameters taken from a
systemic radial velocity fit file based on Lick observatory
velocity measurements over a 19 year period.
|
