Post-perihelion SWAS observations of water vapor in the coma of Comet C/1999 H1 (Lee)

We have monitored the 1(10)-1(01) pure rotational transition of water vapor near 557 GHz toward Comet C/1999 H1 (Lee) over the period 1999 September 5 through 1999 December 8, using the Submillimeter Wave Astronomy Satellite. The measured antenna temperatures implied water production rates that declined from 3.2 x 10(28) s(-1) on 1999 September 5-8 to 1.2 x 1028 s(-1) on 1999 September 25-28. No statistically significant detections of water emission were obtained after 1999 September 28. These post-perihelion observations are consistent with a steady decline in the water production rate, Q(H2O), with increasing heliocentric distance, R-h, that can be fit with a power law Q(H2O) = 1.45 X 10(29) (R-h/AU)(-5.5) s(-1) over the range R-h = 1.3-1.7 AU. (C) 2001 Elsevier Science (USA).