AX J1949.8+2534 is a candidate supergiant fast X-ray transient ( SFXT ) observed in outburst by INTEGRAL ( IGR J19498+2534 ) .
We report on the results of six Neil Gehrels Swift-XRT , one Chandra , and one NuSTAR observation of the source .
We find evidence of rapid X-ray variability on a few ks timescales .
Fortunately , Chandra observed the source in a relatively bright state , allowing us to confidently identify the optical/NIR counterpart of the source .
We also obtained an optical spectrum of this counterpart , which shows an H \alpha emission line and He I absorption features .
The photometry and spectrum of the source allow us to constrain its distance , \sim 7 - 8 kpc , and reddening , A _ { V } = 8.5 - 9.5 .
We find that the star is likely an early B-type Ia supergiant , confirming that AX J1949.8+2534 is indeed an SFXT .