The young HD 73583 (TOI-560) planetary system: two 10-M⊕ mini-Neptunes transiting a 500-Myr-old, bright, and active K dwarf

We present the discovery and characterisation of two transiting planets observed by \textit{TESS} in light curves young bright (V=9.67) star HD73583 (TOI-560). perform an intensive spectroscopic photometric space- ground-based follow-up order to confirm characterise system. found that is a ($\sim 500$~Myr) active with rotational period $12.08 \pm 0.11 $\,d, mass radius $ 0.73 0.02 M_\odot$ $0.65 R_\odot$, respectively. b ($P_b=6.3980420 _{ - 0.0000062 }^{+0.0000067}$ d) has $10.2 _{-3.1}^{+3.4} M_\oplus$ and$2.79 0.10 R_\oplus$, respectively, gives density $2.58 _{-0.81}^{ 0.95} {\rm g\,cm^{-3}}$. c ($P_c= 18.87974 _{-0.00074 }^{+0.00086}$) $9.7_{-1.7} ^ {+1.8} $2.39_{-0.09}^{+0.10} this translates $3.88 _{-0.80}^{+0.91} Both are consistent worlds made solid core surrounded volatile envelope. Because their youth host brightness, they both excellent candidates transmission spectroscopy studies. expect ongoing atmospheric mass-loss for caused stellar irradiation. estimate detection evaporating signatures on H He would be challenging, but doable future instruments.