R. Luque, G. Nowak, E. Pallé, F. Dai, A. Kaminski, E. Nagel, D. Hidalgo, F. Bauer, M. Lafarga, J. Livingston, O. Barragán, T. Hirano, M. Fridlund, D. Gandolfi, A. B. Justesen, M. Hjorth, V. Van Eylen, J. N. Winn, M. Esposito, J. C. Morales, S. Albrecht, R. Alonso, P. J. Amado, P. Beck, J. A. Caballero, J. Cabrera, W. D. Cochran, Sz. Csizmadia, H. Deeg, Ph. Eigmüller, M. Endl, A. Erikson, A. Fukui, S. Grziwa, E. W. Guenther, A. P. Hatzes, E. Knudstrup, J. Korth, K. W. F. Lam, **M. N. Lund**, S. Mathur, P. Montañes-Rodríguez, N. Narita, D. Nespral, P. Niraula, M. Pätzold, C. M. Persson, J. Prieto-Arranz, A. Quirrenbach, H. Rauer, S. Redfield, A. Reiners, I. Ribas, A. M. S. Smith

**Detection and characterization of an ultra-dense sub-Neptune planet orbiting the Sun-like star HD 119130
** See arXiv version

*Submitted to A&A; 9 pages, 8 figures, 4 tables*

**Abstract**

We present the discovery and characterization of a new transiting planet from Campaign 17 of the Kepler extended mission K2. HD 119130 b is a warm sub-Neptune on a 17-d orbit around a bright (V = 9.9 mag) solar-like G3 V star with a mass and radius of \(M_\star = 1.00\pm0.03\,\mathrm{M_\odot}\) and \(R_\star = 1.09\pm0.03\,\mathrm{R_\odot}\), respectively. We model simultaneously the K2 photometry and CARMENES spectroscopic data and derive a radius of \(R_\mathrm{p} = 2.63_{-0.10}^{+0.12}\,\mathrm{R_\oplus}\) and mass of \(M_\mathrm{p} = 24.5_{-4.4}^{+4.4}\,\mathrm{M_\oplus}\), yielding a mean density of \(\rho_\mathrm{p} = 7.4_{-1.5}^{+1.6}\,\mathrm{g\,cm^{-3}}\), which makes it one of the densest sub-Neptune planets known to date. We also detect a linear trend in radial velocities of HD 119130 (\(\dot{\gamma}_{\rm RV}= -0.40^{+0.07}_{-0.07}\,\mathrm{m\,s^{-1}\,d^{-1}}\)) that suggests a long-period companion with a minimum mass on the order of \(33\,\mathrm{M_\oplus}\). If confirmed, it would support a formation scenario of HD 119130 b by migration caused by Kozai-Lidov oscillations.