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WISE J080822.18$-$644357.3 was recently identified as a new M dwarf debrisdisc system and a candidate member of the 45 Myr-old Carina association. Giventhat the strength of its infrared excess ($L_{\rm IR}/L_{\rm \star}\simeq 0.1$)appears to be more consistent with a young protoplanetary disc, we present thefirst optical spectra of the star and reassess its evolutionary and membershipstatus. We find WISE J0808-6443 to be a Li-rich M5 star with strong H$\alpha$emission ($-125 < \textrm{EW} < -65$ \AA\ over 4 epochs) whose strength andbroad width are consistent with accretion at a low level ($\sim$10$^{-10}$$M_{\odot}$ yr$^{-1}$) from its disc. The spectral energy distribution of thestar is consistent with a primordial disc and is well-fit using atwo-temperature blackbody model with $T_{\rm inner}\simeq$ 1100 K and $T_{\rmouter}\simeq$ 240 K. AllWISE multi-epoch photometry shows the system exhibitssignificant variability in the 3.4 $\mu$m and 4.6 $\mu$m bands. We calculate animproved proper motion based on archival astrometry, and combined with a newradial velocity, the kinematics of the star are consistent with membership inCarina at a kinematic distance of $90\pm9$ pc. The spectroscopic andphotometric data are consistent with WISE J0808-6443 being a $\sim$0.1$M_{\odot}$ Classical T-Tauri star and one of the oldest known accreting M-typestars. These results provide further evidence that the upper limit on thelifetimes of gas-rich discs - and hence the timescales to form and evolveprotoplanetary systems - around the lowest mass stars may be longer thanpreviously recognised, or some mechanism may be responsible for regeneratingshort-lived discs at later stages of pre-main sequence evolution.

WISE J080822.18-644357.3 - a 45 Myr-old accreting M dwarf hosting a primordial disc