We report the detection of the H i line at 21 cm from the circumstellar shell around the AGB star X Her using the position-switching technique with the Nançay Radio Telescope .
At the star position the line shows 2 components : ( i ) a broad one ( FWHM \sim 13 km s ^ { -1 } ) centered at - 72.2 km s ^ { -1 } , and ( ii ) a narrow one ( FWHM \sim 4 km s ^ { -1 } ) centered at \sim - 70.6 km s ^ { -1 } .
Our map shows that the source associated to the broad component is asymmetric with material flowing preferentially towards the North-East .
This source extends to \sim 10′ ( \sim 0.4 pc ) from the star in that direction .
On the other hand , the narrow component is detected only at the star position and indicates material flowing away from the observer .
The total mass of atomic hydrogen is \sim 6.5 10 ^ { -3 } M _ { \odot } which , within a factor 2 , agrees with the estimate obtained from IRAS data at 60 \mu m .