WepresentthediscoveryandcharacterizationofanewtransitingplanetfromCampaign17ofthe Kepler extendedmission K2 .HD 119130 bisawarmsub-Neptuneona17-dorbitaroundabright ( V = 9.9 \mathrm { mag } ) solar-likeG3 Vstarwithamassandradiusof M _ { \star } = 1.00 \pm 0.03 \mathrm { M _ { \odot } } and R _ { \star } = 1.09 \pm 0.03 \mathrm { R _ { \odot } } , respectively.Wemodelsimultaneouslythe K2 photometryandCARMENESspectroscopicdataandderivearadiusof R _ { \mathrm { p } } = 2.63 _ { -0.10 } ^ { +0.12 } \mathrm { R _ { \oplus } } andmassof M _ { \mathrm { p } } = 24.5 _ { -4.4 } ^ { +4.4 } \mathrm { M _ { \oplus } } , yieldingameandensityof \rho _ { \mathrm { p } } = 7.4 _ { -1.5 } ^ { +1.6 } \mathrm { g cm ^ { -3 } } , whichmakesitoneofthedensestsub-Neptuneplanetsknowntodate.WealsodetectalineartrendinradialvelocitiesofHD 119130 ( \dot { \gamma } _ { RV } = -0.40 ^ { +0.07 } _ { -0.07 } \mathrm { m s ^ { -1 } d ^ { -1 } } ) thatsuggestsalong-periodcompanionwithaminimummassontheorderof 33 \mathrm { M _ { \oplus } } .Ifconfirmed , itwouldsupportaformationscenarioofHD 119130 bbymigrationcausedbyKozai-Lidovoscillations .