47 Ursae Majoris d (sometimes abbreviated 47 Uma d) is an extrasolar planet approximately 46 light-years away in the constellation of Ursa Major. The planet was discovered located in a long-period orbit (38 years) around the star 47 Ursae Majoris. As of 2011, it is the outermost of three known planets in its planetary system. It has a mass of at least 1.64 times that of Jupiter. It is the longest-period planet detected by Doppler spectroscopy. The evidence of this planet was found by Bayesian Kepler periodogram in March 2010.[1]

An artist's impression of 47 UMa d | |
| Discovery | |
|---|---|
| Discovered by | Gregory and Fischer |
| Discovery site | |
| Discovery date | 6 March 2010 |
Detection method | Doppler spectroscopy (Bayesian Kepler periodogram) |
| Orbital characteristics | |
Semi-major axis | 11.6+2.1 −2.9[1] AU |
| Eccentricity | 0.16+0.09 −0.16[1] |
Orbital period (sidereal) | 14,002+4018 −5095[1] d ~38.33 y |
Time of periastron | 2,451,736+6783 −5051[1] |
Argument of periastron | 110+132 −160[1] |
| Star | 47 Ursae Majoris |
47 Ursae Majoris system | |
|---|---|
| Stars | |
| Planets | |