Bibcode
                                    
                            Distler, Adam; Soares-Furtado, Melinda; Vanderburg, Andrew; Schulte, Jack; Becker, Juliette; Mann, Andrew W.; Howell, Steve B.; Kraus, Adam L.; Kerr, Ronan; Barkaoui, Khalid; Briceño, César; Collins, Karen A.; Conti, Dennis; Jenkins, Jon M.; Limbach, Mary Anne; Quinn, Samuel N.; Schwarz, Richard P.; Seager, Sara; Turner, Jake D.; Twicken, Joseph D.; Winn, Joshua N.; Ziegler, Carl
    Bibliographical reference
                                    The Astronomical Journal
Advertised on:
    
                        3
            
                        2025
            
  Citations
                                    1
                            Refereed citations
                                    1
                            Description
                                    We present the discovery and characterization of TOI-4364b, a young mini-Neptune in the tidal tails of the Hyades cluster, identified through TESS transit observations and ground-based follow-up photometry. The planet orbits a bright M dwarf (K = 9.1 mag) at a distance of 44 pc, with an orbital period of 5.42 days and an equilibrium temperature of   K. The host star's well-constrained age of 710 Myr makes TOI-4364b an exceptional target for studying early planetary evolution around low-mass stars. We determined a planetary radius of  , indicating that this planet is situated near the upper edge of the radius valley. This suggests that the planet retains a modest H/He envelope. As a result, TOI-4364b provides a unique opportunity to explore the transition between rocky super-Earths and gas-rich mini-Neptunes at the early stages of evolution. Its radius, which may still evolve as a result of ongoing atmospheric cooling, contraction, and photoevaporation, further enhances its significance for understanding planetary development. Furthermore, TOI-4364b's moderately high transmission spectroscopy metric of 44.2 positions it as a viable candidate for atmospheric characterization with instruments such as JWST. This target has the potential to offer crucial insights into atmospheric retention and loss in young planetary systems.