TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3178 SUBJECT: GRB050401: Radio observation at 610 MHz with GMRT DATE: 05/04/05 06:45:08 GMT FROM: Poonam Chandra at Tata Inst. Fund.Res. GRB050401: Radio observation at 610 MHz with GMRT Poonam Chandra and Alak Ray (Tata Institute of Fundamental Research (TIFR), Mumbai) report the observation of GRB 050401 with the Giant Metrewave Radio Telescope (GMRT) on 2005 April 2.77 (UT) at 617 MHz frequency with a bandwidth of 32 MHz. No radio emission is seen either at the Optical Transient afterglow position (GCN 3163) or the revised Swift BAT position (GCN 3173). The map rms is 0.23 mJy and 2-Sigma upper limit to the GRB flux density is 0.46 mJy. We thank the GMRT staff, in particular the National Centre for Radio Astrophysics (NCRA) Director Dr. Rajaram Nityananda for making the observations possible, and Dr. Paolo Freire, Yashwant Gupta and collaborators for allowing a part of their time to be used for this observation. GMRT is run by NCRA-TIFR. This observation was Target of Opportunity observation and the observing time was granted as discretionary time at the GMRT.