HD 22496 b: The first ESPRESSO stand-alone planet discovery

Context. The ESPRESSO spectrograph is a new powerful tool developed to detect and characterize extrasolar planets. Its design allows an unprecedented radial velocity precision (down few tens of cm s −1 ) long-term thermomechanical stability. Aims. We present the first stand-alone detection planet by blind search using ESPRESSO; our aim show power instrument in characterizing planetary signals at different periodicities long observing time spans. Methods. used 41 measurements HD 22496 obtained within span 895 days with median photon noise 18 . A analysis was performed test presence planets system account for stellar activity this K5-K7 main-sequence star. For benchmarking comparison, we attempted 43 archive HARPS work compare results yielded two datasets. also four TESS sectors transits. Results. find variations compatible close-in orbital period P = 5.09071 ± 0.00026 when simultaneously accounting effects on longer timescales ( rot 34.99 −0.53 +0.58 days). physical properties minimum mass 5.57 −0.68 +0.73 M ⊕ , right dichotomic regime between rocky gaseous Although not transiting according data, if aligned spin axis, absolute must be below 16 no significant evidence additional data semi-amplitudes above 56 95% confidence. Conclusions. With modest set measurements, capable detecting low-mass constraining habitable zone K dwarfs down rocky-mass regime.