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We present post-outburst (~ 100 days after outburst) radio continuumobservation of the region (~ 30' x 30') around McNeil's nebula (V1647 Orionis).The observations were carried out using the Giant Metrewave Radio Telescope(GMRT), India, at 1272 MHz on 2004 Feb 14.5 UT. Although 8 sources have beendetected within a circular diameter of 25' centred on V1647 Ori, we did notdetect any radio continuum emission from McNeil's nebula. We assign a 5-sigmaupper limit of 0.15 mJy/beam for V1647 Ori where the beam size is 5.6" x 2.7".Even at higher frequencies of 4.9 and 8.5 GHz (VLA archival data), no radioemission has been detected from this region. Three scenarios namely, emissionfrom homogeneous HII region, ionised stellar wind and shock ionised gas, areexplored in the light of our GMRT upper-limit. For the case of homogeneous HIIregion, the radius of the emitting region is constrained to be <~ 26 AUcorresponding to a temperature >~ 2,500 K, which is consistent with thereported radio and H-alpha emission. In the ionised stellar wind picture, ourupper limit of radio emission translates to the ratio of mass loss rate andterminal velocity, (M_dot/v_infinity) < 1.2-1.8 x 10^(-10) (M_sun/yr)/(km/s).On the other hand, if the stellar wind shocks the dense neutral (molecular)cloud, the radio upper limit implies that the fraction of the wind encounteringthe dense obstacle is <50%. Based on a recent measurement of X-ray outburst andlater monitoring, the expected radio emission has been estimated. Using ourradio limit, the radius (<~ 36 AU) and electron density (>~ 7.2 x 10^7 cm^(-3)of the radio emitting plasma have been constrained using a two phase medium inpressure equilibrium for a volume filling factor of 0.9.Comment: To appear in Astronomy and Astrophysics (8 pages including 1 Table  and 3 Figures

Post-outburst radio observation of the region around McNeil's nebula (V1647 Orionis)