Observations of 18 cm OH emission and absorption from Halley's comet.

The 1665 and 1667 MHz OH intensity toward Halley's comet has been monitored during the period October 1985 to April 1986. The flux density variation during the course of the apparition roughly follows the predictions of Schloerb and Gerard (1985), although a systematically lower flux than Schloerb and Gerard predicted is found. The relative intensities of these lines are approximately in the ratio expected for thermodynamic equilibrium.