Fabry-Perot Observations of Comet Hale-Bopp tex2html_wrap_inline12 Velocity Fields

F.L. Roesler, D.A. Klinglesmith III, F. Scherb, E.J. Mierkiewicz (U Wisc), R.J. Oliversen (NASA/GSFC)

We have obtained Doppler-sliced images of tex2html_wrap_inline12 emission from Comet Hale-Bopp, using a 15-cm, dual-etalon, Fabry-Perot/CCD imaging spectrometer at the McMath-Pierce 0.8-meter west auxiliary telescope of the National Solar Observatory on Kitt Peak. The 6-arcmin field of view was centered on the comet nucleus, and the spectral resolution was 0.4Å (20km/sec). The observations consisted of ``data cubes,'' i.e., a sequence of images of the 6158Å emission doublet at velocity steps of 12.5 or 25km/sec, covering a range from -75km/sec to +75km/sec in the comet reference frame. We were able to follow the comet for 1 to 1 tex2html_wrap_inline16 hours each clear night. We obtained useable data cubes on at least ten nights between February 25 and April 16. These data are being examined to investigate the comet-solar wind interaction. We will present both still images and time-lapse movies showing sequences of ion velocities and accelerations on the plane of the sky.