Doppler Observations of the Impact of Comet S 1 . 9 Fragment A

In this paper we present an attempt to detect Doppler effect on Jupiter during the impact of the fragment A of the comet, Shoemaker-Levy 9. We give a short description of the technique used to observe the impact, then present the observations and finally a theoretical analysis and interpretation. The instrumentation used is an advanced and more sensitive version of the Magneto-Optical Filter (normally used in Helioseisrnology to detect global oscillations of the Sun) and a 40 cm aperture telescope. The observed signal consists of a double peak transient that could be interpreted as the signature of an expanding perturbation. Introduction For the past several years, we have been observing global solar oscillations manifested as a doppler shift of the sodium D absorption lines. The line-of-sight velocity variations are measured using a Magneto Optical Filter (MOF) in which two extremely narrow passbands are switched sequentially between two wavelengths. The difference in intensity in the two wings of the solar line profile yields the instantaneous velocity. Sunlight is sufficiently intense that no telescope is needed, the sun being tracked continuously with a simple heliostat.