Two temperate super-Earths transiting a nearby late-type M dwarf

In the age of JWST, temperate terrestrial exoplanets transiting nearby late-type M dwarfs provide unique opportunities for characterising their atmospheres, as well searching biosignature gases. We report here discovery and validation two super-Earths LP 890-9 (TOI-4306, SPECULOOS-2), a relatively low-activity (32 pc) M6V star. The inner planet, 890-9b, was first detected by TESS (and identified TOI-4306.01) based on four sectors data. Intensive photometric monitoring system with SPECULOOS Southern Observatory then led to second outer 890-9c (also SPECULOOS-2c), previously undetected TESS. orbital period this planet later confirmed MuSCAT3 follow-up observations. With mass 0.118$\pm$0.002 $M_\odot$, radius 0.1556$\pm$0.0086 $R_\odot$, an effective temperature 2850$\pm$75 K, is second-coolest star found host planets, after TRAPPIST-1. has 2.73 d, $1.320_{-0.027}^{+0.053}$ $R_\oplus$, receives incident stellar flux 4.09$\pm$0.12 $S_\oplus$. similar size $1.367_{-0.039}^{+0.055}$ $R_\oplus$ 8.46 d. 0.906 $\pm$ 0.026 $S_\oplus$, it located within conservative habitable zone, very close its limit. Although masses planets remain be measured, we estimated potential atmospheric characterisation via transmission spectroscopy using mass-radius relationship that, TRAPPIST-1 second-most favourable habitable-zone known so far. remarkable offers another rare opportunity study around our smallest coolest neighbours.