The distance , star formation history and global properties of the Local Group dIrr galaxy SagDIG are derived based on an [ I - ( V - I ) ] colour–magnitude diagram of \sim 1550 stars .
A distance of 1.06 \pm 0.10 Mpc is obtained from the I magnitude of the TRGB .
This corresponds to 1.17 Mpc to the barycenter of the Local Group and 1.34 to M 31 , being DDO 210 , at 0.35 Mpc , the nearest galaxy to SagDIG .
The metallicity is estimated from the colour of the RGB to be [ Fe/H ] = -2.45 \pm 0.25 .
SagDIG is hence a probable member of the Local Group and a candidate for the lowest-metallicity star forming galaxy known .

The radial density profile of the galaxy has been obtained together with other integrated properties ( magnitude , colour and central surface density ) .
The galaxy density profile is fitted by an exponential law of scale length 27 \aas@@fstack { \prime \prime } 1 , corresponding to 140 pc .

The star formation history of SagDIG has been analysed , based on synthetic colour–magnitude diagrams .
The galaxy is currently in a high star formation activity epoch , forming stars at a rate about 10 times greater than the average for its entire life .
This is a common feature of galaxies classified as dIrrs .