Fabry-Perot Observations of Comet Austin

We present preliminary results of a program to observe Comet Austin (1990cl) from 16 April to 4 May and from 11 May to 27 May 1990 using the West Auxiliary of the McMath Solar Telescope on Kitt Peak, Arizona. The observations were made with a 15-cm dual-etalon Fabry-Perot scanning and imaging spectrometer with two modes of operation: a high resolution mode with a velocity resolution of 1.2 km/s and a medium resolution mode with a velocity resolution of 10 km/s. Scanning data was obtained with an RCA C31034A photomultiplier tube and imaging data was obtained with a Photometrics LN2 cooled CCD camera with a 516 by 516 Ford chip. The results include: (1) information on the coma outflow velocity from high resolution spectral profiles of [OI]6300 and NH2 emissions, (2) gaseous water production rates from medium resolution observations of [OI]6300, (3) spectra of H2O+ emissions in order to study the ionized component of the coma, (4) spatial distribution of H2O+ emission features from sequences of velocity resolved images (datacubes), and (5) spatial distribution of [OI]6300 and NH2 emission from medium resolution images. The field of view on the sky was 10.5 arcminutes in diameter. In the imaging mode the CCD was binned 4 by 4 resulting in 7".6 per pixel and a subarray readout for a field of view of 10'.5.