We report on the discovery of a double nucleus in M 83 , based on measurements of the line of sight velocity distribution of stars observed at near infrared wavelengths with the VLT ISAAC spectrograph .
We observe two peaks separated by 2 \aas@@fstack { \prime \prime } 7 in the velocity dispersion profile of light from late-type stars measured along a slit 0 \aas@@fstack { \prime \prime } 6 wide , centered on the peak of K band emission and with P.A .
51.7° .
The first peak coincides with the peak of the K band light distribution , widely assumed to be the galaxy nucleus .
The second peak , of almost equal strength , almost coincides with the center of symmetry of the outer isophotes of the galaxy .
The secondary peak location has little K band emission , and appears to be significantly extincted , even at near infrared wavelengths .
It also lies along a mid-infrared bar , previously identified by Gallais et al .
( 1991 ) and shows strong hydrogen recombination emission at 1.875 \mu m. If we interpret the observed stellar velocity dispersion as coming from a virialized system , the two nuclei would each contain an enclosed mass of 13.2 \times 10 ^ { 6 } M _ { \sun } within a radius of 5.4 pc .
These could either be massive star clusters , or supermassive dark objects .