We have observed GRS 1739–278 with the ROSAT HRI on March 31 , 1996 .
The improved X-ray position proves the identification with an earlier discovered variable radio source .
We derive an extinction of A _ { V } = 14 \pm 2 from the dust scattering halo , which implies a distance of d \approx 6–8.5 kpc .
Thus , GRS 1739–278 radiates at least near the Eddington limit for a 1 M _ { \odot } compact object .

The existence of the dust scattering halo necessitates a prolonged X-ray activity period prior to the ROSAT observation .
Combined with the non-detection by Granat during an earlier galactic center observation , we speculate that the X-ray turn-on of GRS 1739–278 happened in Nov./Dec .
1995 .