Reduced spectra

Forums Comets Spectrum of Comet 46P/Wirtanen Reduced spectra

Robin Leadbeater

Here are my reduced spectra.

The diffuse coma integrated along the slit above and below the bright condensed region between 15 and 105 arcsec from the centre.  Since the coma extended beyond the length of the slit the sky background was measured separately and subtracted. All the usual molecular components are there (CN is particularly intense in the UV) but no obvious Sodium.

The bright central region (6 arcsec diameter), again with the  separately measured sky background subtracted showing the same emission components seen in the outer coma  superimposed on a continuum spectrum with absorption lines.

The overall shape of the continuum and the absorption features match that of the solar spectrum (here compared with a solar analogue star taken the same night), though there appears to be a lack of flux from the comet around 4000-5000A ie the reflected light from the comet is deficient in the blue part of the spectrum