 HD 40307 d is an extrasolar planet orbiting the star HD 40307 , located 42 light @-@ years from Earth in the direction of the southern constellation Pictor . The planet was discovered by the radial velocity method , using the HARPS apparatus in June 2008 . It is the most massive of the six proposed planets in the system . The planet is about 20 times the mass of Jupiter and orbits its star with a period of 143 days .
The planet is the first extrasolar planet discovered to have a mass that is less than that of Jupiter but larger than that of Neptune . The planet has a very large ecc