Further improved X-ray position and possible optical/nIR counterpart for XTE J1637-489

We report a further refinement of the position of the recently discovered X-ray transient XTE J1637-498 (Markwardt, Pereira and Swank, ATEL #1699). Using 1 ks of Swift XRT Photon Counting mode data and 3 Swift UVOT v band images from the observation described in Wijnands et al. (ATEL #1700), we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue) of RA, Dec = 249.26112, -49.86128 deg which is equivalent to:
RA (J2000): 16 37 2.67
Dec (J2000): -49 51 40.6
with an uncertainty of 1.8 arcsec (radius, 90% confidence).